Coupler and laser chip

Abstract

The utility model provides a first coupler and a laser chip. The coupler comprises a substrate, an N-InP layer, a P-InP layer, a waveguide layer and a doping layer. The waveguide layer comprises a nonlinear transition section, a first non-transition section and a second non-transition section. The non-linear transition section outer contour line comprises a first arc line and a second arc line. The first arc line is recessed towards the waveguide center. The second arc protrudes towards the center of the waveguide. The waveguide width between the first arc line and the second arc line tends to the waveguide width of the second non-transition section, so that the width changes quickly when the waveguide width is large, and changes slowly when the waveguide width is small, the fundamental mode coupling efficiency is ensured, excitation of a high-order mode is avoided, the heat insulation length of the non-linear transition section is shortened, and the power consumption is reduced. Therefore, the overall length of the first coupler is effectively shortened. The doping layer has a high refractive index, so that more light fields can be distributed in the layer structure, and light spots can be further amplified. When light spots of the same size are formed, the required waveguide width is small based on the doping layer, and dependence on the waveguide width is weakened.

Description

Technical Field

[0001] This disclosure relates to the field of optical communication technology, and in particular to a coupler and a laser chip. Background Technology

[0002] With the development of new business and application models such as cloud computing, mobile internet, and video, advancements in optical communication technology have become increasingly important. In optical communication technology, the optical module, as one of the key components in optical communication equipment, enables photoelectric signal conversion; and in the development of optical communication technology, the data transmission rate of optical modules is required to continuously improve. Utility Model Content

[0003] Some embodiments provide a coupler and a laser chip, which perform mode switching through the coupler to achieve relatively low-loss coupling between the laser chip and optical fibers of different sizes.

[0004] In some embodiments, a coupler is provided, comprising:

[0005] Substrate;

[0006] An N-InP layer is located above the substrate;

[0007] The P-InP layer is located above the N-InP layer;

[0008] The waveguide layer includes a nonlinear gradient segment, a first non-gradient segment, and a second non-gradient segment. One end of the nonlinear gradient segment is connected to the first non-gradient segment, and the other end is connected to the second non-gradient segment. The outer contour of the nonlinear gradient segment includes a first arc and a second arc. The first arc is concave towards the center of the waveguide, and the second arc is convex towards the center of the waveguide. Along the direction from the first non-gradient segment to the second non-gradient segment, the waveguide width between the first arc and the second arc gradually decreases.

[0009] A doped layer is located within the N-InP layer, and the refractive index of the doped layer is greater than that of the P-InP layer.

[0010] The above technical solution has the following advantages or beneficial effects: The coupler includes a substrate, an N-InP layer, a P-InP layer, a waveguide layer, and a doped layer. The refractive indices of the N-InP layer and the P-InP layer are both lower than the refractive index of the waveguide layer, thus confining the light field within the waveguide layer for transmission. The waveguide layer includes a nonlinear gradient section, a first non-gradient section, and a second non-gradient section. One end of the nonlinear gradient section is connected to the first non-gradient section, and the other end is connected to the second non-gradient section. The outer contour of the nonlinear gradient section includes a first arc and a second arc. The first arc is a concave arc, recessed towards the center of the waveguide. The second arc is a convex arc, protruding towards the center of the waveguide. Furthermore, the waveguide width between the first and second arcs tends to be the waveguide width of the second non-gradient section. This ensures that the width changes rapidly when the waveguide width is large and slowly when the waveguide width is narrow, thereby ensuring the fundamental mode coupling efficiency and avoiding the excitation of higher-order modes. The thermal insulation length of the nonlinear gradient section is shortened, thus effectively shortening the overall length of the first coupler. A doped layer is formed within the N-InP layer. This doped layer has a high refractive index, which helps to distribute more light field within the layer structure, further amplifying the spot size. Therefore, when forming the same spot size, the required waveguide width is smaller due to the doped layer, reducing dependence on waveguide width and simplifying the waveguide etching process.

[0011] In some embodiments, the refractive index of the doped layer is greater than that of the P-InP layer and less than that of the waveguide layer.

[0012] The above technical solution has the following advantages or beneficial effects: the refractive index of the doped layer is greater than that of the P-InP layer. The higher refractive index of the doped layer helps to distribute more light field within the layer structure, further amplifying the spot size. The refractive index of the doped layer is lower than that of the waveguide layer, allowing the main light field to be distributed more extensively within the waveguide layer for transmission, which helps to reduce transmission loss.

[0013] In some embodiments, the waveguide width of the first non-gradient segment is greater than the waveguide width of the second non-gradient segment.

[0014] The above technical solution has the following advantages or beneficial effects: the width of the first non-gradient waveguide segment depends on the single-mode conditions of the laser chip, while the width of the second non-gradient waveguide segment depends on the coupling efficiency with the fiber array. If the width of the first non-gradient waveguide segment is greater than that of the second non-gradient waveguide segment, it facilitates the coupling between the first non-gradient segment and the laser chip, improving their coupling efficiency. It also facilitates the coupling between the second non-gradient segment and the fiber array, improving their coupling efficiency as well.

[0015] In some embodiments, the waveguide layer is buried within the P-InP layer.

[0016] The above technical solution has the following advantages or beneficial effects: the P-InP layer has a high refractive index, and the waveguide layer is buried in the P-InP layer, which helps to confine the light field within the waveguide layer for transmission and reduce transmission loss.

[0017] In some embodiments, a laser chip is provided, comprising:

[0018] The light-emitting area includes a first end and a second end. The first end emits a first light beam, and the second end emits a second light beam. Neither the first light beam nor the second light beam carries information.

[0019] A first beam splitter is located on the optical path of the first beam transmission to split the first beam into a first beam splitter and a second beam splitter; the first beam splitter and the second beam splitter are transmitted along one side of the light-emitting area;

[0020] The second beam splitter is located on the optical path of the second beam transmission to split the second beam into a third beam splitter and a fourth beam splitter; the third beam splitter and the fourth beam splitter are transmitted along the other side of the light-emitting area;

[0021] The first electroabsorption modulation region is located on the transmission optical path of the first split beam and is configured to modulate the first split beam to generate a first optical signal.

[0022] The second electro-absorption modulation region is located on the transmission optical path of the second beam splitter and is configured to modulate the second beam splitter to generate a second optical signal; the second electro-absorption modulation region and the first electro-absorption modulation region are respectively located on one side of the light-emitting region;

[0023] The third electroabsorption modulation region is located on the transmission optical path of the third beam splitter and is configured to modulate the signal of the third beam splitter to generate a third optical signal.

[0024] The fourth electro-absorption modulation region is located on the transmission optical path of the fourth beam splitter and is configured to modulate the signal of the fourth beam splitter to generate a fourth optical signal; the fourth electro-absorption modulation region and the third electro-absorption modulation region are respectively located on the other side of the light-emitting region;

[0025] The first coupler is located on the output optical path of the first electroabsorption modulation region and is used to perform mode conversion on the first optical signal.

[0026] The second coupler, located on the output optical path of the second electroabsorption modulation region, is used to perform mode conversion on the second optical signal;

[0027] The third coupler, located in the output optical path of the third electroabsorption modulation region, is used to perform mode conversion on the third optical signal;

[0028] The fourth coupler, located on the output optical path of the fourth electroabsorption modulation region, is used to perform mode conversion on the fourth optical signal.

[0029] The above technical solution has the following advantages or beneficial effects: The laser chip includes a light-emitting region, a first beam splitter, a second beam splitter, a first electro-absorption modulation region, a second electro-absorption modulation region, a third electro-absorption modulation region, and a fourth electro-absorption modulation region. The light-emitting region includes a first end and a second end. The first end emits a first beam, and the second end emits a second beam. Neither the first nor the second beam carries information. The first beam splitter is located on the transmission optical path of the first beam to split the first beam into a first beam splitter and a second beam splitter. The second beam splitter is located on the transmission optical path of the second beam to split the second beam into a third beam splitter and a fourth beam splitter. The transmission optical path of the first beam splitter has a first electro-absorption modulation region, the transmission optical path of the second beam splitter has a second electro-absorption modulation region, the transmission optical path of the third beam splitter has a third electro-absorption modulation region, and the transmission optical path of the fourth beam splitter has a fourth electro-absorption modulation region. The first electro-absorption modulation region modulates the signal of the first beam splitter to generate a first optical signal. The second electro-absorption modulation region modulates the signal of the second beam splitter to generate a second optical signal. The third electro-absorption modulation region modulates the signal of the third beam splitter, generating the third optical signal. The fourth electro-absorption modulation region modulates the signal of the fourth beam splitter, generating the fourth optical signal. At this point, the laser chip achieves optical signal array output, improving chip integration and transmission rate. The first and second beams output from the first beam splitter propagate along one side of the emitting region, while the third and fourth beams output from the second beam splitter propagate along the other side of the emitting region. Therefore, the first and second electro-absorption modulation regions are located on one side of the emitting region, and the third and fourth electro-absorption modulation regions are located on the other side, which is beneficial for laser chip miniaturization.

[0030] The laser chip integrates a first coupler, a second coupler, a third coupler, and a fourth coupler. The first coupler, located in the output optical path of the first electroabsorption modulation region, performs mode conversion on the first optical signal to match the mode of the fiber array. The second coupler, located in the output optical path of the second electroabsorption modulation region, performs mode conversion on the second optical signal to match the mode of the fiber array. The third coupler, located in the output optical path of the third electroabsorption modulation region, performs mode conversion on the third optical signal to match the mode of the fiber array. The fourth coupler, located in the output optical path of the fourth electroabsorption modulation region, performs mode conversion on the fourth optical signal to match the mode of the fiber array. By performing mode conversion, the small light spot output by the laser chip is converted into a large light spot to match the mode of the fiber array, thereby achieving relatively low-loss coupling between the laser chip and optical fibers of different sizes.

[0031] In some embodiments, the first coupler includes:

[0032] Substrate;

[0033] An N-InP layer is located above the substrate;

[0034] The P-InP layer is located above the N-InP layer;

[0035] The waveguide layer includes a nonlinear gradient segment, a first non-gradient segment, and a second non-gradient segment. One end of the nonlinear gradient segment is connected to the first non-gradient segment, and the other end is connected to the second non-gradient segment. The first non-gradient segment faces the first electro-absorption modulation region.

[0036] A doped layer is located within the N-InP layer, and the refractive index of the doped layer is greater than that of the P-InP layer.

[0037] The above technical solution has the following advantages or beneficial effects: The first coupler includes a substrate, an N-InP layer, a P-InP layer, a waveguide layer, and a doped layer. The refractive indices of both the N-InP layer and the P-InP layer are lower than the refractive index of the waveguide layer, thus confining the light field within the waveguide layer for transmission. The outer contour of the nonlinear gradient section is an arc, with one side being the first arc and the other side being the second arc. The first arc is concave, recessed towards the center of the waveguide. The second arc is convex, protruding towards the center of the waveguide. Furthermore, the waveguide width between the first and second arcs tends to be the same as the waveguide width of the second non-gradient section. This ensures that the waveguide width changes rapidly when it is large and slowly when it is narrow, thereby ensuring the fundamental mode coupling efficiency and avoiding the excitation of higher-order modes. The thermal insulation length of the nonlinear gradient section is shortened, thus effectively shortening the overall length of the first coupler. A doped layer is formed in the N-InP layer. The doped layer has a high refractive index, which helps to distribute more light field in this layer structure, further amplifying the spot size. When forming the same spot size, the required waveguide width is smaller due to the setting of the doped layer, which reduces the dependence on the waveguide width and reduces the difficulty of the waveguide etching process.

[0038] In some embodiments, the laser chip includes:

[0039] A first transmission waveguide connects the first end of the light-emitting area to the first beam splitter to receive the first beam into the first beam splitter.

[0040] A second transmission waveguide connects the second end of the light-emitting region to the second beam splitter to guide the second beam into the second beam splitter. The second transmission waveguide includes:

[0041] The first bending zone bends from the second end of the light-emitting zone toward the first end to turn the transmission direction of the second beam to the first end of the light-emitting zone, thereby placing the first beam splitter and the second beam splitter on the same side of the light-emitting zone.

[0042] The above technical solution has the following advantages or beneficial effects: The laser chip includes a first transmission waveguide and a second transmission waveguide. The first transmission waveguide connects the first end of the emitting region to the first beam splitter, guiding the first beam emitted from the emitting region into the first beam splitter. The second transmission waveguide connects the second end of the emitting region to the second beam splitter, guiding the second beam emitted from the emitting region into the second beam splitter. The second transmission waveguide includes a first bending region, which bends from the second end of the emitting region towards the first end, turning the transmission direction of the second beam back to the first end of the emitting region. This allows the first beam splitter and the second beam splitter to be located on the same side of the emitting region, which is beneficial for miniaturizing the laser chip.

[0043] In some embodiments, the laser chip includes:

[0044] A third transmission waveguide connects the first output end of the first beam splitter to the first electro-absorption modulation region to transmit the first beam to the first electro-absorption modulation region. The third transmission waveguide includes a second bend region.

[0045] A fourth transmission waveguide connects the second output end of the first beam splitter to the second electro-absorption modulation region to transmit the second beam to the second electro-absorption modulation region. The fourth transmission waveguide includes a third bending region. The third bending region and the second bending region bend toward one side of the light-emitting region to guide the second beam and the first beam to one side of the light-emitting region, respectively.

[0046] The fifth transmission waveguide connects the first output end of the second beam splitter to the third electro-absorption modulation region to transmit the third beam to the third electro-absorption modulation region. The fifth transmission waveguide includes a fourth bend region.

[0047] A sixth transmission waveguide connects the second output end of the second beam splitter to the fourth electro-absorption modulation region to transmit the fourth beam to the fourth electro-absorption modulation region. The sixth transmission waveguide includes a fifth bending region. The fifth bending region and the fourth bending region bend toward the other side of the light-emitting region to guide the fourth beam and the third beam to the other side of the light-emitting region, respectively.

[0048] The above technical solution has the following advantages or beneficial effects: The laser chip includes a third transmission waveguide, a fourth transmission waveguide, a fifth transmission waveguide, and a sixth transmission waveguide. The third transmission waveguide connects the first output end of the first beam splitter to the first electro-absorption modulation region, and receives the first beam output from the first output end of the first beam splitter into the first electro-absorption modulation region. The first electro-absorption modulation region modulates the signal of the first beam to generate a first optical signal. The fourth transmission waveguide connects the second output end of the first beam splitter to the second electro-absorption modulation region, and receives the second beam output from the second output end of the first beam splitter into the second electro-absorption modulation region. The second electro-absorption modulation region modulates the signal of the second beam to generate a second optical signal. The fifth transmission waveguide connects the first output end of the second beam splitter to the third electro-absorption modulation region, and receives the third beam output from the first output end of the second beam splitter into the third electro-absorption modulation region. The third electro-absorption modulation region modulates the signal of the third beam to generate a third optical signal. The sixth transmission waveguide connects the second output end of the second beam splitter to the fourth electro-absorption modulation region, allowing the fourth beam output from the second output end of the second beam splitter to enter the fourth electro-absorption modulation region. The fourth electro-absorption modulation region modulates the fourth beam to generate a fourth optical signal.

[0049] The third transmission waveguide includes a second bending region, guiding the transmission direction of the first beam splitter. The fourth transmission waveguide includes a third bending region, guiding the transmission direction of the second beam splitter. The third and second bending regions bend towards one side of the light-emitting region to guide the second and first beam splitters to one side of the light-emitting region, respectively. Therefore, the first and second electro-absorption modulation regions are located on one side of the light-emitting region. The fifth transmission waveguide includes a fourth bending region, and the sixth transmission waveguide includes a fifth bending region. The fifth and fourth bending regions bend towards the other side of the light-emitting region to guide the fourth and third beam splitters to the other side of the light-emitting region, respectively. Therefore, the third and fourth electro-absorption modulation regions are located at the other end of the light-emitting region. This rationally distributes the transmission directions of multiple optical signals, avoids optical crosstalk, and the rational deployment of the first, second, third, and fourth electro-absorption modulation regions is beneficial for chip miniaturization.

[0050] In some embodiments, the first electroabsorption modulation region and the second electroabsorption modulation region are offset from each other on one side of the light-emitting region; the third electroabsorption modulation region and the fourth electroabsorption modulation region are offset from each other on the other side of the light-emitting region.

[0051] The first electroabsorption modulation region includes:

[0052] Substrate;

[0053] An N-InP layer is located above the substrate;

[0054] The second active layer is located above the N-InP layer;

[0055] The P-InP layer is located above the second active layer;

[0056] First electrode section;

[0057] Second electrode section;

[0058] A first radio frequency electrode is connected to the first electrode portion by a first electrical connection bridge to electrically connect the first radio frequency electrode and the first electrode portion, so as to input a first differential drive modulation signal to the first electroabsorption modulation region.

[0059] The second radio frequency electrode is connected to the second electrode portion by a second electrical connection bridge to electrically connect the second radio frequency electrode and the second electrode portion, so as to input the second differential drive modulation signal to the first electroabsorption modulation region.

[0060] The first DC electrode is connected to the first RF electrode by a first connecting resistor and a third electrical connecting bridge to electrically connect the first DC electrode and the first RF electrode, and further electrically connect the first DC electrode and the first electrode portion to input a first differential reverse bias voltage to the first electroabsorption modulation region.

[0061] The second DC electrode is connected to the second RF electrode by a second connecting resistor and a fourth electrical connecting bridge, so as to electrically connect the second DC electrode and the second RF electrode, and further electrically connect the second DC electrode and the second electrode portion, so as to input a second differential reverse bias voltage to the first electroabsorption modulation region.

[0062] The above technical solution has the following advantages or beneficial effects: the first, second, third, and fourth electro-absorption modulation regions adopt a differential driving mode to reduce power consumption. These electro-absorption modulation regions have the same structure. The first electro-absorption modulation region includes a substrate, an N-InP layer, a second active layer, a P-InP layer, a first electrode portion, and a second electrode portion. P-type carriers are transported to the second active layer via the first electrode portion and the P-InP layer, and N-type carriers are transported to the second active layer via the second electrode portion and the N-InP layer. To achieve differential driving, the first electro-absorption modulation region includes a first radio frequency electrode, a second radio frequency electrode, a first DC electrode, and a second DC electrode. The first radio frequency electrode is electrically connected to the first electrode portion to input a first differential driving modulation signal to the first electro-absorption modulation region. The second radio frequency electrode is electrically connected to the second electrode portion to input a second differential driving modulation signal to the first electro-absorption modulation region. The first DC electrode is electrically connected to the first radio frequency electrode, and the first DC electrode is electrically connected to the first electrode portion to input a first differential reverse bias voltage to the first electro-absorption modulation region. When the second DC electrode is electrically connected to the second RF electrode, it is also electrically connected to the second electrode section, inputting a second differential reverse bias voltage to the second electroabsorption modulation region. Under the action of the first and second differential reverse bias voltages, the first electroabsorption modulation region operates. When the first electroabsorption modulation region operates, the first and second electrode sections simultaneously apply a first differential drive modulation signal and a second differential drive modulation signal with opposite phases, forming a differential drive mode. Based on the electro-optic modulation effect, the light entering the second active layer is modulated by the differential drive modulation signal, generating an optical signal carrying information.

[0063] In some embodiments, the first DC electrode is located on one side of the first RF electrode, and the second RF electrode is located on the other side of the first RF electrode;

[0064] The first radio frequency electrode is located on one side of the second radio frequency electrode, and the second DC electrode is located on the other side of the second radio frequency electrode.

[0065] The above technical solution has the following advantages or beneficial effects: With the first DC electrode located on one side of the first RF electrode and the second RF electrode located on the other side of the first RF electrode, the first DC electrode, the first RF electrode, and the second RF electrode are arranged sequentially. With the first RF electrode located on one side of the second RF electrode and the second DC electrode located on the other side of the second RF electrode, the first DC electrode, the first RF electrode, the second RF electrode, and the second DC electrode are arranged sequentially on the surface of the laser chip. This linear arrangement occupies a small area, which is beneficial for arranging all the electrodes of the four electro-absorption modulation regions on the surface of the laser chip, thereby meeting the differential drive mode requirements of the four electro-absorption modulation regions. Attached Figure Description

[0066] To more clearly illustrate the technical solutions in this disclosure, the accompanying drawings used in some embodiments of this disclosure will be briefly described below. Obviously, the drawings described below are merely drawings of some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings. Furthermore, the drawings described below can be regarded as schematic diagrams and are not intended to limit the actual size of the product, the actual flow of the method, the actual timing of the signals, etc. involved in the embodiments of this disclosure.

[0067] Figure 1 This is a partial architecture diagram of an optical communication system according to some embodiments;

[0068] Figure 2 This is a partial structural diagram of a host computer according to some embodiments;

[0069] Figure 3 This is a structural diagram of an optical module according to some embodiments;

[0070] Figure 4 An exploded view of an optical module according to some embodiments;

[0071] Figure 5a This is a structural diagram of the internal structure of an optical module according to some embodiments;

[0072] Figure 5b This is an exploded view of the interior of an optical module according to some embodiments;

[0073] Figure 6a This is a schematic diagram of the structure of a light emitting component according to some embodiments. Figure 1 ;

[0074] Figure 6b This is a schematic diagram of the structure of a light emitting component according to some embodiments. Figure 2 ;

[0075] Figure 7a This is a schematic diagram of the optical path of an optical receiving component according to some embodiments;

[0076] Figure 7b This is a structural diagram of a refracting element according to some embodiments;

[0077] Figure 7c An exploded view of a refracting element according to some embodiments;

[0078] Figure 8a An exploded view of a circuit board assembly according to some embodiments;

[0079] Figure 8b This is a cross-sectional view of a circuit board assembly according to some embodiments;

[0080] Figure 9aThis is a partial view of a circuit board assembly according to some embodiments;

[0081] Figure 9b This is a partial structural diagram of a light emitting component according to some embodiments;

[0082] Figure 10a This is a diagram of the internal structure of a laser chip according to some embodiments;

[0083] Figure 10b This is a schematic diagram of the optical path of a laser chip according to some embodiments;

[0084] Figure 11a This is a diagram of a first coupler structure according to some embodiments;

[0085] Figure 11b This is a cross-sectional view of a first coupler according to some embodiments;

[0086] Figure 11c This is a schematic diagram of a waveguide layer planar structure according to some embodiments;

[0087] Figure 11d This is a schematic diagram of another waveguide layer planar structure according to some embodiments;

[0088] Figure 12 This is a cross-sectional structural diagram of a light-emitting region according to some embodiments;

[0089] Figure 13 This is a three-dimensional structural diagram of a light-emitting area according to some embodiments;

[0090] Figure 14 This is a partial cross-sectional view of a laser chip according to some embodiments;

[0091] Figure 15 A first electroabsorption modulation region profile structure according to some embodiments Figure 1 ;

[0092] Figure 16 A first electroabsorption modulation region profile structure according to some embodiments Figure 2 ;

[0093] Figure 17 A first electroabsorption modulation region profile structure according to some embodiments Figure 3 ;

[0094] Figure 18 A first electroabsorption modulation region profile structure according to some embodiments Figure 4 ;

[0095] Figure 19 This is a laser component structure according to some embodiments;

[0096] Figure 20 An exploded view of a laser assembly according to some embodiments;

[0097] Figure 21 A surface structure of a laser component according to some embodiments Figure 1 ;

[0098] Figure 22 This is a surface layout structure diagram of a laser component according to some embodiments;

[0099] Figure 23 A surface structure of a laser component according to some embodiments Figure 2 ;

[0100] Figure 24 This is a schematic diagram of a capacitor arrangement according to some embodiments;

[0101] Figure 25 This is a schematic diagram of a laser chip circuit according to some embodiments;

[0102] Figure 26 This is a schematic diagram of the structure of a laser chip according to some embodiments;

[0103] Figure 27 A laser chip structure according to some embodiments Figure 1 ;

[0104] Figure 28 A laser chip structure according to some embodiments Figure 2 ;

[0105] Figure 29 A laser chip structure according to some embodiments Figure 3 ;

[0106] Figure 30 This is a schematic diagram of a laser chip fabrication method according to some embodiments;

[0107] Figure 31 This is a schematic diagram of the fabrication process of a first electrical connection bridge according to some embodiments;

[0108] Figure 32 This is a schematic diagram of a laser chip fabrication process according to some embodiments. Figure 1 ;

[0109] Figure 33 This is a schematic diagram of a laser chip fabrication process according to some embodiments. Figure 2 ;

[0110] Figure 34 This is a schematic diagram of a laser chip fabrication process according to some embodiments. Figure 3 . Detailed Implementation

[0111] The following description, in conjunction with the accompanying drawings, provides a clear and detailed account of some embodiments of this disclosure. However, the described embodiments are merely some, and not all, of the embodiments described herein. All other embodiments obtained by those skilled in the art based on the embodiments provided herein are within the scope of protection of this disclosure.

[0112] Unless the context otherwise requires, throughout the specification and claims, the term "comprising" is interpreted as open and inclusive, meaning "including, but not limited to"; the terms "first" and "second" should not be construed as indicating or implying relative importance or indicating an upper limit on the number; the term "multiple" means two or more; the term "connection" should be interpreted broadly, for example, "connection" can be a fixed connection, a detachable connection, or an integral part, and can be a direct connection or an indirect connection through an intermediate medium; the use of the terms "applicable to" or "configured to" implies open and inclusive language, which does not exclude applicability to or configuration to devices performing additional tasks or steps; descriptions such as "parallel," "perpendicular," "identical," "consistent," and "aligned" are not limited to absolute mathematical theoretical relationships, but also include acceptable error ranges arising in practice, and differences based on the same design concept but due to manufacturing reasons.

[0113] In optical communication technology, to establish information transmission between information processing devices, information is loaded onto light, and the speed of light propagation is used to transmit the information. This light carrying information is called an optical signal. When optical signals are transmitted in optical information transmission equipment, optical power loss can be reduced, enabling long-distance transmission of optical signals. At the same time, the cost of optical information transmission equipment such as optical fibers is lower than that of electrical information transmission equipment such as copper wires. Therefore, optical communication technology can achieve high-speed, long-distance, and low-cost information transmission.

[0114] Information processing equipment typically includes optical network units (ONUs), gateways, routers, switches, mobile phones, computers, servers, tablets, televisions, etc., while optical information transmission equipment typically includes optical fibers and optical waveguides. Information processing equipment can only recognize and process electrical signals, while optical communication technology uses optical signals for transmission, requiring optical modules to convert between optical and electrical signals.

[0115] An optical module enables the conversion between optical signals and electrical signals between information processing equipment and optical information transmission equipment. In some embodiments, at least one of the optical signal input or output terminals of the optical module is connected to an optical fiber, and at least one of the electrical signal input or output terminals of the optical module is connected to an optical network terminal. A first optical signal from the optical fiber is transmitted to the optical module, which converts the first optical signal into a first electrical signal and transmits the first electrical signal to the optical network terminal. A second electrical signal from the optical network terminal is transmitted to the optical module, which converts the second electrical signal into a second optical signal and transmits the second optical signal to the optical fiber.

[0116] Since multiple information processing devices can transmit information via electrical signals, at least one of these devices needs to be directly connected to the optical module, rather than all of them. Here, the information processing device directly connected to the optical module is also referred to as the host computer of the optical module. Furthermore, the optical signal input or output terminal of the optical module is called the optical port, and the electrical signal input or output terminal is called the electrical port.

[0117] Figure 1 This is a partial structural diagram of an optical communication system according to some embodiments. Figure 1 As shown, the optical communication system mainly includes a remote information processing device 1000, a local information processing device 2000, a host computer 100 for optical modules, an optical module 200, an optical fiber 101, and a network cable 103. Among them, the optical fiber 101 is an optical information transmission device, and the network cable 103 is an electrical information transmission device.

[0118] In some embodiments, one end of the optical fiber 101 extends toward the remote information processing device 1000, and the other end of the optical fiber 101 is connected to the optical module 200 through the optical port of the optical module 200. The optical signal can undergo total internal reflection in the optical fiber 101, and the propagation of the optical signal in the direction of total internal reflection can almost maintain the original optical power. The optical signal undergoes multiple total internal reflections in the optical fiber 101 to transmit the optical signal from the remote information processing device 1000 to the optical module 200, or to transmit the optical signal from the optical module 200 to the remote information processing device 1000, thereby realizing long-distance information transmission based on low power loss.

[0119] The optical communication system includes one or more optical fibers 101. In some embodiments, the optical fiber 101 is detachably connected to the optical module 200; in some embodiments, the optical fiber 101 is non-detachably connected to the optical module 200.

[0120] The host computer 100 is configured to provide data signals to the optical module 200, or receive data signals from the optical module 200, or monitor or control the working status of the optical module 200.

[0121] The host computer 100 includes a housing for accommodating the optical module 200, and an optical module interface 102 disposed on the housing. The optical module 200 is inserted into the housing through the optical module interface 102 to establish a unidirectional or bidirectional electrical signal connection between the host computer 100 and the optical module 200.

[0122] The host computer 100 also includes an external power interface that can connect to an electrical signal network. In some embodiments, the external power interface includes a Universal Serial Bus (USB) interface or a network cable interface 104. The network cable interface 104 is configured to connect a network cable 103 to establish a unidirectional or bidirectional electrical signal connection between the host computer 100 and the network cable 103.

[0123] One end of the network cable 103 is connected to the local information processing device 2000, and the other end is connected to the host computer 100, so as to establish an electrical signal connection between the local information processing device 2000 and the host computer 100 through the network cable 103. In some embodiments, a third electrical signal emitted by the local information processing device 2000 is transmitted to the host computer 100 through the network cable 103. The host computer 100 generates a second electrical signal based on the third electrical signal. The second electrical signal from the host computer 100 is transmitted to the optical module 200. The optical module 200 converts the second electrical signal into a second optical signal and transmits the second optical signal to the optical fiber 101. The second optical signal is transmitted in the optical fiber 101 to the remote information processing device 1000.

[0124] In some embodiments, a first optical signal from a remote information processing device 1000 is transmitted through an optical fiber 101, and the first optical signal from the optical fiber 101 is transmitted to an optical module 200. The optical module 200 converts the first optical signal into a first electrical signal, and transmits the first electrical signal to a host computer 100. The host computer 100 generates a fourth electrical signal based on the first electrical signal and transmits the fourth electrical signal to a local information processing device 2000.

[0125] In some embodiments, the optical module is a tool for converting optical signals to electrical signals. During the conversion process, the information does not change, but the encoding or decoding method of the information changes.

[0126] In addition to optical network terminals, the host computer 100 also includes optical line terminals (OLTs), optical network equipment (ONTs), or data center servers.

[0127] Figure 2This is a partial structural diagram of a host computer according to some embodiments. To clearly show the connection relationship between the optical module 200 and the host computer 100, Figure 2 Only the structure of the host computer 100 related to the optical module 200 is shown. For example... Figure 2 As shown, in some embodiments, the host computer 100 further includes a PCB circuit board 105 disposed in the receiving cavity, and a cage 106 disposed on the surface of the PCB circuit board 105; the optical module 200 is inserted into the cage 106 and fixed by the cage 106.

[0128] In some embodiments, a heat sink 107 is provided on the cage 106 to dissipate heat for the optical module; in some embodiments, the heat sink 107 has protruding structures such as fins to increase the heat dissipation area.

[0129] In some embodiments, an electrical connector is provided inside the cage 106, which is configured to connect to the electrical port of the optical module 200.

[0130] In some embodiments, the optical module 200 is inserted into the cage 106 of the host computer 100, and the cage 106 fixes the optical module 200. The heat generated by the optical module 200 is conducted to the cage 106 and then diffused through the heat sink 107.

[0131] In some embodiments, the optical module 200 is inserted into the cage 106 of the host computer 100, and the electrical port of the optical module 200 is connected to the electrical connector inside the cage 106, thereby establishing an electrical signal connection between the optical module 200 and the host computer 100.

[0132] In some embodiments, the optical port of the optical module 200 is connected to the optical fiber 101, thereby enabling the optical module 200 to establish an optical signal connection with the optical fiber 101.

[0133] Figure 3 This is a structural diagram of an optical module according to some embodiments. Figure 4 This is an exploded view of an optical module according to some embodiments. Figure 3 and Figure 4 As shown, in some embodiments, the optical module 200 includes a shell, which comprises an upper shell 201 and a lower shell 202. The upper shell 201 covers the lower shell 202, forming two openings 204 and 205, one of which is an electrical port and the other is an optical port. In some embodiments, the shell forms an opening that serves as both an electrical port and an optical port.

[0134] In some embodiments, the upper housing 201 and the lower housing 202 are made of metal materials, which facilitates electromagnetic shielding and heat dissipation.

[0135] The assembly method of combining the upper housing 201 and the lower housing 202 facilitates the installation of the circuit board 300, the light emitting component 400, the light receiving component 500, etc. into the housing. The upper housing 201 and the lower housing 202 can encapsulate and protect the above-mentioned devices.

[0136] The direction of the line connecting the two openings 204 and 205 can be consistent with or inconsistent with the length direction of the optical module 200. For example, opening 204 is located at the end of the optical module 200. Figure 3 The opening 205 is also located at the end of the optical module 200 (right end). Figure 3 (The left end). Alternatively, opening 204 is located at the end of optical module 200, while opening 205 is located on the side of optical module 200.

[0137] In some embodiments, the lower housing 202 includes a base plate 2021 and two lower side plates 2022 located on both sides of the base plate 2021 and perpendicular to the base plate 2021; the upper housing 201 includes a cover plate 2011, which covers the two lower side plates 2022 of the lower housing 202 to form the aforementioned housing.

[0138] In some embodiments, the lower housing 202 includes a base plate 2021 and two lower side plates 2022 located on both sides of the base plate 2021 and perpendicular to the base plate 2021; the upper housing 201 includes a cover plate 2011 and two upper side plates located on both sides of the cover plate 2011 and perpendicular to the cover plate 2011. The two upper side plates and the two lower side plates 2022 are combined to realize that the upper housing 201 covers the lower housing 202.

[0139] like Figure 3 and Figure 4As shown, in some embodiments, the optical module includes a circuit board 300 disposed within a housing. The circuit board 300 includes circuit traces, electronic components, and chips, etc. The electronic components and chips are connected according to the circuit design through the circuit traces to realize functions such as power supply, electrical signal transmission, and grounding. Electronic components may include, for example, capacitors, resistors, transistors, and metal-oxide-semiconductor field-effect transistors (MOSFETs). Chips may include microcontroller units (MCUs), laser driver chips, transimpedance amplifiers (TIAs), limiting amplifiers (LAs), clock and data recovery chips (CDRs), power management chips, and digital signal processing (DSP) chips.

[0140] In some embodiments, the circuit board includes a rigid circuit board, which, due to its relatively rigid material, can also serve a load-bearing function, such as being able to stably support the aforementioned electronic components and chips; the rigid circuit board can also be inserted into an electrical connector in the cage 106 of the host computer 100.

[0141] In some embodiments, the circuit board further includes a flexible circuit board, which can be used independently or in conjunction with a rigid circuit board.

[0142] In some embodiments, the circuit board further includes gold fingers formed on its end surface, the gold fingers consisting of a plurality of independent pins.

[0143] In some implementations, the gold fingers 301 are disposed on one side of the surface of the circuit board 300 (e.g., Figure 4 (as shown on the upper surface); In some implementations, the gold fingers 301 are disposed on the upper and lower surfaces of the circuit board 300 to provide a greater number of pins, thereby adapting to situations where the number of pins is large.

[0144] In some implementations, the gold fingers of the circuit board extend from the opening 204 and are inserted into the electrical connector of the host computer 100; the circuit board is inserted into the cage 106, and the gold fingers 301 are connected to the electrical connector inside the cage 106. The gold fingers 301 are configured to establish an electrical connection with the host computer, enabling electrical connection functions such as power supply, grounding, two-wire synchronous serial (Inter-Integrated Circuit, I2C) signal transmission, and data signal transmission.

[0145] In some embodiments, the optical module 200 further includes an unlocking component 600 located outside its housing. The unlocking component 600 is configured to establish a fixed connection between the optical module 200 and the host computer, or to release the fixed connection between the optical module 200 and the host computer.

[0146] For example, the unlocking component 600 is located on the outside of the two lower side plates 2022 of the lower housing 202, and includes a locking component that matches the cage 106 of the host computer 100. When the optical module 200 is inserted into the cage 106, the locking component of the unlocking component 600 fixes the optical module 200 in the cage 106; when the unlocking component 600 is pulled, the locking component of the unlocking component 600 moves accordingly, thereby changing the connection relationship between the locking component and the host computer, so as to release the fixation between the optical module 200 and the host computer, thereby allowing the optical module 200 to be pulled out of the cage 106.

[0147] In some embodiments, the optical module includes a light emitting component 400.

[0148] In some embodiments, the optical module includes an optical receiving component 500.

[0149] In some embodiments, at least one of the light emitting component 400 or the light receiving component 500 is located on the side of the circuit board 300 away from the gold finger 301.

[0150] In some embodiments, the light emitting component 400 and the light receiving component 500 are physically separated from the circuit board 300, and then electrically connected to the circuit board 300 through corresponding flexible circuit boards or electrical connectors.

[0151] In some embodiments, at least one of the light emitting component or the light receiving component may be directly disposed on the circuit board 300. For example, at least one of the light emitting component or the light receiving component may be disposed on the surface of the circuit board 300 or the side of the circuit board 300.

[0152] Figure 5a This is a diagram illustrating the internal structure of an optical module according to some embodiments. Figure 5b This is an exploded view of the interior of an optical module according to some embodiments. Figure 5a and Figure 5b As shown, in some embodiments, the surface of the circuit board 300 is provided with a light receiving component 500 and a light emitting component 400.

[0153] In some embodiments, the light emitting component 400 is configured to receive electrical signals and convert the electrical signals into optical signals.

[0154] In some embodiments, the light emitting component 400 may include a housing 440 and a cover plate 450. The housing 440 and the cover plate 450 are closed together to form a cavity. The cavity can be used to house and protect devices such as laser components. The housing 440 includes a base plate and a side plate, the side plate being connected to the top edge of the base plate, the base plate and the side plate forming a housing with a top opening. The top of the side plate supports and connects to the emitting cover plate 450.

[0155] In some embodiments, the light emitting component 400 may include a laser assembly 410. The laser assembly 410 is disposed inside a housing 440. The housing 440 has good thermal conductivity, which is beneficial for heat dissipation of the laser assembly 410. The laser assembly 410 includes a substrate 420 and a laser chip 900. The laser chip 900 is electrically connected to the substrate 420, and the substrate 420 is electrically connected to the circuit board 300, thereby establishing an electrical connection between the laser chip 900 and the circuit board 300, supplying power to the laser chip 900 or inputting high-frequency signals. The laser assembly 410 can emit multi-channel optical signals to achieve high-speed transmission.

[0156] In some embodiments, a circuit pattern is formed on the surface of the substrate 420, including signal traces, pads, etc. The laser chip 900 is electrically connected to the corresponding circuit pattern on the surface of the substrate 420 to supply power or input high-frequency signals to the laser chip 900 through the substrate 420.

[0157] In some embodiments, the laser chip 900 is located on the surface of the substrate 420, or the laser chip 900 is embedded in the substrate 420.

[0158] In some embodiments, the optical emitting component 400 may include an optical fiber array 430. The optical fiber array 430 is located inside the housing 440. The optical fiber array 430 includes a fixing member 431 and an optical fiber bundle 432. The optical fiber bundle 432 is fixed by the fixing member 431 and includes multiple optical fibers, which can correspondingly transmit the optical signals emitted by the laser chip 900, realize multi-channel transmission, and improve the overall transmission rate. For example, if the laser chip 900 emits four optical signals, the optical fiber bundle 432 includes four optical fibers to correspondingly transmit the four optical signals.

[0159] In some embodiments, the laser chip 900 is coupled to the end face of the fiber array 430, and the multiple optical signals emitted by the laser chip 900 are directly coupled into the laser chip 900.

[0160] In some embodiments, the light receiving component 500 is located on one side of the light emitting component 400. The light receiving component 500 is configured to receive optical signals and convert the optical signals into electrical signals.

[0161] In some embodiments, the light receiving component 500 may include a refracting element 510.

[0162] In some embodiments, the light receiving component 500 may include a light receiving chip 520.

[0163] In some embodiments, the light receiving component 500 may include a TIA530.

[0164] In some embodiments, the refracting element 510 includes an optical fiber 511 extending toward the optical receiver chip 520, with the end of the optical fiber 511 exposed above the optical receiver chip 520. A reflective end face 512 is formed at the end of the optical fiber 511, and this reflective end face 512 is exposed above the optical receiver chip 520. The reflective end face 512 is used to reflect and change the transmission direction of the optical signal transmitted through the optical fiber 511, thereby reflecting the optical signal transmitted through the optical fiber 511 to the optical receiver chip 520, thus achieving a reversal of the optical path.

[0165] In some embodiments, the TIA530 is located on the surface of the circuit board 300 and is situated to one side of the optical receiver chip 520. The optical receiver chip 520 converts the received optical signal into a photocurrent signal, and the TIA530 converts the photocurrent signal into a photovoltage signal and amplifies the photovoltage signal.

[0166] Figure 6a This is a schematic diagram of the structure of a light emitting component according to some embodiments. Figure 1 , Figure 6b This is a schematic diagram of the structure of a light emitting component according to some embodiments. Figure 2 .like Figure 6a and Figure 6b As shown, in some embodiments, the light emitting component 400 includes a housing 440 and a cover plate 450, which are connected to form an emitting cavity, which can be used to accommodate laser components, lenses and other devices.

[0167] In some embodiments, housing 440 includes a base plate and a side plate, the side plate being connected to the top edge of the base plate, the base plate and the side plate forming a housing with a top opening. The top of the side plate supports and connects to a launch cover 450.

[0168] In some embodiments, such as Figure 6a As shown, a first notch 441 is formed on the side plate at the left end of the housing 440, and the first notch 441 connects to the inner cavity of the housing 440. The fiber optic array 430 passes through the first notch 441, and multiple fibers of the fiber optic array 430 extend from inside the housing 440 along the first notch 441.

[0169] In some embodiments, such as Figure 6b In the indicated direction, a second notch 442 is formed at the right end of the housing 440. The bottom of the second notch 442 extends to the bottom plate of the housing 440, and both sides of the second notch 442 extend to the side plates on both sides of the housing 440.

[0170] In some embodiments, a first boss 443 and a second boss 444 are formed on the top of the housing 440. The first boss 443 and the second boss 444 are formed by the outer wall of the side plate of the housing 440 protruding outward from the housing 440. The right end of the first boss 443 and the right end of the second boss 444 extend beyond the right side of the second notch 442.

[0171] Figure 7a This is a schematic diagram of the optical path of an optical receiving component according to some embodiments. Figure 7b This is a structural diagram of a refracting element according to some embodiments. Figure 7c This is an exploded view of a refractive element according to some embodiments. For example... Figures 7a-7c As shown, in some embodiments, the reflective end face 512 reflects the optical signal transmitted by the optical fiber 511 to change the transmission direction of the optical signal in the optical fiber 511, thereby reflecting the optical signal transmitted by the optical fiber 511 to the optical receiving chip 520 to realize optical signal reception.

[0172] In some embodiments, the refracting element 510 may include an optical fiber 511. The light-emitting end face of the optical fiber 511 has a reflective end face 512.

[0173] In some embodiments, the refracting element 510 may include a first optical fiber support portion 513 and a second optical fiber support portion 514. The first optical fiber support portion 513 and the second optical fiber support portion 514 are arranged vertically opposite each other, and a plurality of optical fibers 511 are held between them. The plurality of optical fibers 511 form an optical fiber array. A V-groove 517 is formed on the bottom surface of the first optical fiber support portion 513 to embed the optical fibers 511.

[0174] In some embodiments, the refracting element 510 may include an optical fiber fixing portion 515. The optical fiber fixing portion 515 is located at the tail of the second optical fiber support portion 514 to fix the optical fiber 511. The optical fiber fixing portion 515 protects and cushions the optical fiber 511, thereby preventing fiber breakage. Exemplarily, the optical fiber fixing portion 515 is made of soft rubber, which protects and cushions the optical fiber 511.

[0175] In some embodiments, the length of the first optical fiber support portion 513 is longer than that of the second optical fiber support portion 514, and there is a space between the end of the second optical fiber support portion 514 and the end of the first optical fiber support portion 513, which is reserved for coating space of the optical fiber fixing portion 515.

[0176] In some embodiments, the reflective end face 512 is an inclined surface, and the received optical signal transmitted by the optical fiber 511 undergoes total internal reflection at the reflective end face 512. For example, the inclination angle of the reflective end face 512 is 46-50°, such as 48°.

[0177] In some embodiments, the optical fiber 511 passes through one end of the first optical fiber support 513 and extends to the outside of the other end of the first optical fiber support 513, such that the reflective end face 512 is located outside the other end of the first optical fiber support 513. One end of the optical fiber fixing part 515 is connected to one end of the second optical fiber support 514, and the other end of the optical fiber fixing part 515 is fixedly connected to the end of the optical fiber 511 to support the end of the optical fiber 511.

[0178] In some embodiments, a protective surface 516 is formed on the end face of the first optical fiber support portion 513. The protective surface 516 surrounds the side of the reflective end face 512 to protect the reflective end face 512. For example, the protective surface 516 is an inclined surface with an inclination angle of 46-50°, such as 48°.

[0179] In some embodiments, the reflective end face 512 and the protective end face 516 are formed by grinding and polishing. The end face of the optical fiber 511 is ground to a certain tilt angle to form the reflective end face 512. The optical fiber 511 is cylindrical, and the cross-section of the reflective end face 512 after grinding is elliptical, so the bottom of the optical fiber 511 is exposed relative to the first optical fiber support portion 513.

[0180] In some embodiments, a certain gap is left between the fiber fixing part 515 and the surface of the circuit board 300 to prevent the fiber fixing part 515 from sticking to the optical adhesive on the surface of the circuit board 300 used to fix the second fiber support part 514, and to maintain the binding force of the fiber fixing part 515 on the fiber 511.

[0181] In some embodiments, the light receiver chip 520 is located on the surface of the circuit board 300. When the model of the light receiver chip 520 is fixed, its thickness is fixed, and therefore the distance from its photosensitive surface to the surface of the circuit board 300 is fixed.

[0182] In some embodiments, the preset distance between the reflective end face 512 and the light receiving chip 520 is small to ensure that the light signal reflected from the reflective end face 512 can be transmitted to the photosensitive surface of the light receiving chip 520 and then received by the light receiving chip 520. The thickness of the second optical fiber support portion 514 is small to ensure that the distance between the reflective end face 512 and the light receiving chip 520 meets the preset distance. For example, the thickness of the second optical fiber support portion 514 is smaller than that of the first optical fiber support portion 513 to ensure that the distance between the reflective end face 512 and the light receiving chip 520 meets the preset distance.

[0183] In some embodiments, there is a certain distance between the end of the second optical fiber support 514 and the reflective end face 512, and the length of the second optical fiber support 514 does not extend below the reflective end face 512, leaving space for the optical receiving chip 520 to be installed, so as to ensure that the distance from the reflective end face 512 to the optical receiving chip 520 meets the preset distance.

[0184] Figure 8a This is an exploded view of a circuit board assembly according to some embodiments. Figure 8b This is a cross-sectional view of a circuit board assembly according to some embodiments. For example... Figure 8a and Figure 8b As shown, in some embodiments, the surface of the circuit board 300 is provided with a light receiving component 500 and a light emitting component 400.

[0185] In some embodiments, the surface of the circuit board 300 has a through hole 302. The housing 440 is embedded in the through hole 302, thereby fixing the housing 440 to the circuit board 300.

[0186] In some embodiments, the fiber bundle 432 extends out of the housing 440 through the first notch 441 of the housing 440.

[0187] In some embodiments, the sidewalls on both sides of the bottom end of the housing 440 are recessed inward to support the circuit board 300 on both sides, thereby embedding the housing 440 in the through hole 302.

[0188] Figure 9a This is a partial view of a circuit board assembly according to some embodiments. Figure 9b This is a partial structural diagram of a light emitting component according to some embodiments. Figure 9a and Figure 9b As shown, in some embodiments, the surface of the circuit board 300 is provided with a light receiving component 500 and a light emitting component 400.

[0189] In some embodiments, the surface of the circuit board 300 has a through hole 302. The housing 440 is embedded in the through hole 302, thereby fixing the housing 440 to the circuit board 300.

[0190] In some embodiments, the laser chip 900 can be a single-channel laser chip or an array-emitting laser chip. The following embodiments use an array-emitting laser chip as an example for illustrative purposes.

[0191] In some embodiments, the laser chip 900 emits multi-channel optical signals. The laser chip 900 has multiple output ports, which are optically connected to the input ports of the fiber array 430, thereby transmitting multiple optical signals to the corresponding optical fibers within the fiber bundle 432.

[0192] In some embodiments, the laser chip 900 is coupled to the end face of the fiber array 430. The laser chip 900 and the fiber array 430 are fixedly connected by a refractive index matching optical adhesive.

[0193] In some embodiments, a circuit pattern is formed on the surface of the substrate 420. The substrate 420 is electrically connected to the circuit board 300.

[0194] In some embodiments, the laser chip 900 may be an EML laser chip. An EML laser chip includes a distributed feedback laser (DFB) and an electro absorption modulator (EAM). Correspondingly, the laser chip 900 includes a light-emitting region and an electro absorption modulation region.

[0195] In some embodiments, the light-emitting region emits light from the edge, and the emitted light does not carry a signal. An electro-absorption modulation region is disposed in the light-emitting path of the light-emitting region to modulate the signal-free light emitted by the light-emitting region, thereby generating an optical signal.

[0196] In some embodiments, a bias current circuit is provided on the surface of the circuit board 300. The output terminal of the bias current circuit is electrically connected to the surface of the substrate 420, and the surface of the substrate 420 is electrically connected to the light-emitting area, thereby establishing an electrical connection between the bias current circuit and the light-emitting area to apply a forward bias current to the light-emitting area. When the forward bias current is greater than a threshold, the light-emitting area emits light.

[0197] In some embodiments, a bias voltage circuit is provided on the surface of the circuit board 300. The output terminal of the bias voltage circuit is electrically connected to the substrate 420, and the surface of the substrate 420 is electrically connected to the electroabsorption modulation region, thereby establishing an electrical connection between the bias voltage circuit and the electroabsorption modulation region to apply a reverse bias voltage to the electroabsorption modulation region.

[0198] In some embodiments, a driving circuit is provided on the surface of the circuit board 300. The output terminal of the driving circuit is electrically connected to the substrate 420, and the surface of the substrate 420 is electrically connected to the electroabsorption modulation region, thereby establishing an electrical connection between the driving circuit and the electroabsorption modulation region to input a driving modulation signal to the electroabsorption modulation region.

[0199] In some embodiments, a reverse bias voltage and a modulation current signal are provided to the electroabsorption modulation region. Under the action of the reverse bias voltage, the intensity of the light emitted by the light-emitting region changes with the modulation current signal, thereby modulating the intensity and generating an optical signal carrying information.

[0200] In some embodiments, the electroabsorption modulation region is a PIN device that alters the light transmittance using the electroabsorption effect, wherein the I layer is composed of multiple quantum well waveguides. Modulation of the optical signal can be achieved through its quantum confinement effect. When a reverse electric field is applied to the active region of the electroabsorption modulation region, the PIN is reverse-biased, causing a shift in the electron-hole pair energy levels of the multiple quantum wells, thereby shifting the absorption peak position and ultimately modulating and generating an optical signal.

[0201] Figure 10a This is a diagram of the internal structure of a laser chip according to some embodiments. Figure 10b This is a schematic diagram of the optical path of a laser chip according to some embodiments. Figure 10a and Figure 10b As shown, in some embodiments, the laser chip 900 is an on-chip integrated edge-emitting multi-channel optical signal, realizing multi-channel integration.

[0202] In some embodiments, the laser chip 900 integrates an on-chip light-emitting region, an electro-absorption modulation region, and an end-face coupler to realize optical signal array output and low-loss coupling with the fiber array 430 to improve the transmission rate.

[0203] In some embodiments, the laser chip 900 includes a light-emitting region. The light-emitting region emits a beam of light without carrying information from each end of the active region.

[0204] In some embodiments, the laser chip 900 integrates a beam splitter to split a beam of light emitted from the light-emitting region, thereby emitting multiple beams. An electro-absorption modulation region is located on the transmission path of the corresponding light to modulate its signal. Taking the laser chip 900 emitting four beams as an example, the laser chip 900 includes a first beam splitter and a second beam splitter. The first beam splitter splits the light emitted from one end of the active region, and the second beam splitter splits the light emitted from the other end of the active region, generating four beams. The first beam splitter and the second beam splitter can each be a 1×2 multimode interference coupler.

[0205] In some embodiments, the laser chip 900 includes multiple electro-absorption modulation regions. The multiple beams generated by beam splitting are transmitted via transmission waveguides, and each beam undergoes signal modulation through its respective electro-absorption modulation region to emit multi-channel optical signals. For example, if the laser chip 900 emits four optical signals, then the laser chip 900 includes one light-emitting region and four electro-absorption modulation regions.

[0206] In some embodiments, the output end face of the laser chip 900 integrates multiple end face couplers to perform mode conversion, converting the small light spot output by the laser chip 900 into a large light spot to match the mode spot of the fiber array 430, thereby achieving relatively low-loss coupling between the laser chip 900 and optical fibers of different sizes.

[0207] The following example illustrates the use of a laser chip 900 emitting four optical signals.

[0208] In some embodiments, the laser chip 900 may include a light-emitting region 910. The light-emitting region 910 emits a beam of light without carrying information from each end of the active region. One end of the light-emitting region 910 emits a first beam, and the other end emits a second beam. Neither the first beam nor the second beam carries information. If the end emitting the first beam is defined as the first end of the light-emitting region 910, and the end emitting the second beam is defined as the second end of the light-emitting region 910, then the light-emitting region 910 includes a first end and a second end, with the first end emitting the first beam and the second end emitting the second beam.

[0209] In some embodiments, the second beam is guided to the same propagation direction as the first beam. For example, the propagation direction of the second beam is guided from the second end to the first end so that the second beam's propagation direction is aligned with that of the first beam.

[0210] In some embodiments, the laser chip 900 may include a first beam splitter 920. The first beam splitter 920 is located in the transmission optical path of the first beam, and the first beam is input into the first beam splitter 920, where it is split into a first beam splitter and a second beam splitter. The first beam splitter is output from a first output end of the first beam splitter 920, and the second beam splitter is output from a second output end of the first beam splitter 920.

[0211] In some embodiments, the laser chip 900 may include a second beam splitter 930. The second beam splitter 930 and the first beam splitter 920 are located on the same side of the light-emitting region. Exemplarily, the second beam splitter 930 and the first beam splitter 920 are located on the same side as the first end. The second beam splitter 930 is located in the transmission optical path of the second beam, and the second beam is fed into the second beam splitter 930, where it is split into a third beam and a fourth beam. The third beam is output from the first output end of the second beam splitter 930, and the fourth beam is output from the second output end of the second beam splitter 930. Thus, there are four beams to be modulated in the output optical path of the light-emitting region 910.

[0212] In some embodiments, the laser chip 900 may include a first electro-absorption modulation region 940. The first electro-absorption modulation region 940 is optically connected to the first output end of the first beam splitter 920 to receive the first beam split. The first electro-absorption modulation region 940 is located in the transmission optical path of the first beam split to modulate the signal of the first beam split, thereby generating a first optical signal.

[0213] In some embodiments, the laser chip 900 may include a second electro-absorption modulation region 950. The second electro-absorption modulation region 950 is optically connected to the second output end of the first beam splitter 920 to receive the second beam split. The second electro-absorption modulation region 950 is located in the transmission optical path of the second beam split to modulate the signal of the second beam split, thereby generating a second optical signal.

[0214] In some embodiments, the laser chip 900 may include a third electroabsorption modulation region 960. The third electroabsorption modulation region 960 is optically connected to the first output end of the second beam splitter 930 to receive the third beam. The third electroabsorption modulation region 960 is located in the transmission optical path of the third beam to modulate the signal of the third beam, thereby generating a third optical signal.

[0215] In some embodiments, the laser chip 900 may include a fourth electro-absorption modulation region 970. The fourth electro-absorption modulation region 970 is optically connected to the second output end of the second beam splitter 930 to receive the fourth beam. The fourth electro-absorption modulation region 970 is located on the transmission optical path of the fourth beam to modulate the signal of the fourth beam, generating a fourth optical signal. Thus, the laser chip 900 modulates and generates four optical signals, realizing an optical signal array output, improving chip integration, and increasing transmission rate.

[0216] In some embodiments, the first electroabsorption modulation region 940 and the second electroabsorption modulation region 950 may be located on one side of the light-emitting region 910, and the third electroabsorption modulation region 960 and the fourth electroabsorption modulation region 970 may be located on the other side of the light-emitting region 910. The reasonable distribution of multiple electroabsorption modulation regions is beneficial for chip miniaturization.

[0217] In some embodiments, the first end of the light-emitting region 910 is optically connected to the first beam splitter 920, and the second end of the light-emitting region 910 is optically connected to the second beam splitter 930. The two light-emitting ends of the first beam splitter 920 are optically connected to the first electro-absorption modulation region 940 and the second electro-absorption modulation region 950, respectively, and the two light-emitting ends of the second beam splitter 930 are optically connected to the third electro-absorption modulation region 960 and the fourth electro-absorption modulation region 970, respectively.

[0218] In some embodiments, the light-emitting region 910 is connected to transmission waveguides between the first beam splitter 920 and the second beam splitter 930, respectively. A transmission waveguide is connected between the first light-emitting end of the first beam splitter 920 and the light-incident end of the first electro-absorption modulation region 940, and a transmission waveguide is connected between the second light-emitting end and the light-incident end of the second electro-absorption modulation region 950. A transmission waveguide is connected between the first light-emitting end of the second beam splitter 930 and the light-incident end of the third electro-absorption modulation region 960, and a transmission waveguide is connected between the second light-emitting end and the light-incident end of the fourth electro-absorption modulation region 970.

[0219] In some embodiments, a first transmission waveguide 981 is connected between the first end of the light-emitting region 910 and the first beam splitter 920 to guide the first light beam into the first beam splitter 920 for beam splitting. The first transmission waveguide 981 can be a straight waveguide.

[0220] In some embodiments, a second transmission waveguide 982 is connected between the second end of the light-emitting region 910 and the second beam splitter 930 to allow the second light beam to be fed into the second beam splitter 930 for beam splitting.

[0221] In some embodiments, the second transmission waveguide 982 is a bent waveguide, which includes a first bending region 9821, with straight waveguides connected to both ends of the first bending region 9821. The first bending region 9821 bends from the second end of the light-emitting region 910 toward the first end of the light-emitting region 910, turning the optical path and thus reflecting the second beam back to the first end of the light-emitting region 910. In this way, the first beam splitter 920 and the second beam splitter 930 can be located on the same side of the light-emitting region 910, which is beneficial for chip miniaturization.

[0222] In some embodiments, the first output end of the first beam splitter 920 is optically connected to the input end of the first electroabsorption modulation region 940. A third transmission waveguide 983 is connected between the first output end of the first beam splitter 920 and the input end of the first electroabsorption modulation region 940. The third transmission waveguide 983 includes a second bending region 9831, which bends the transmission direction of the first beam splitter. Straight waveguides are connected to both ends of the second bending region 9831.

[0223] In some embodiments, the second output end of the first beam splitter 920 is optically connected to the input end of the second electro-absorption modulation region 950. A fourth transmission waveguide 984 is connected between the second output end of the first beam splitter 920 and the input end of the second electro-absorption modulation region 950. The fourth transmission waveguide 984 includes a third bending region 9841, which bends the transmission direction of the second beam splitter. Straight waveguides are connected to both ends of the third bending region 9841.

[0224] In some embodiments, the first output end of the second beam splitter 930 is optically connected to the input end of the third electroabsorption modulation region 960. A fifth transmission waveguide 985 is connected between the first output end of the second beam splitter 930 and the input end of the third electroabsorption modulation region 960. The fifth transmission waveguide 985 includes a fourth bending region 9851, which bends the transmission direction of the third beam splitter. Straight waveguides are connected to both ends of the fourth bending region 9851.

[0225] In some embodiments, the second output end of the second beam splitter 930 is optically connected to the input end of the fourth electro-absorption modulation region 970. A sixth transmission waveguide 986 is connected between the second output end of the second beam splitter 930 and the input end of the fourth electro-absorption modulation region 970. The sixth transmission waveguide 986 includes a fifth bending region 9861, which bends the transmission direction of the fourth beam splitter. Straight waveguides are connected to both ends of the fifth bending region 9861.

[0226] In some embodiments, the second bending region 9831 and the third bending region 9841 bend toward the same side, guiding the first beam splitter and the second beam splitter to the same side.

[0227] In some embodiments, the fourth bending region 9851 and the fifth bending region 9861 bend toward the same side, guiding the third beam splitter and the fourth beam splitter to the same side.

[0228] In some embodiments, the second bending region 9831 and the third bending region 9841 bend along the two output ends of the first beam splitter 920 toward the first side, and the fourth bending region 9851 and the fifth bending region 9861 bend along the two output ends of the second beam splitter 930 toward the second side opposite to the first side. In this way, the first beam splitter and the second beam splitter are guided to the first side, and the third beam splitter and the fourth beam splitter are guided to the second side, so as to reasonably deploy the optical path and facilitate the miniaturization of the highly integrated laser chip.

[0229] In some embodiments, the second bending region 9831 and the third bending region 9841 are bent toward the first side, respectively, guiding the first beam splitter and the second beam splitter to one side of the light-emitting region 910 for transmission. The first electroabsorption modulation region 940 and the second electroabsorption modulation region 950 are located on one side of the light-emitting region 910.

[0230] In some embodiments, the fourth bending region 9851 and the fifth bending region 9861 are bent toward the second side, respectively, guiding the third and fourth beam splitters to the other side of the light-emitting region 910 for transmission. The third electro-absorption modulation region 960 and the fourth electro-absorption modulation region 970 are located on the other side of the light-emitting region 910. The reasonable arrangement of the four electro-absorption modulation regions is beneficial for chip miniaturization.

[0231] In some embodiments, as the integration density of optical modules increases, it is necessary to further reduce the power consumption of the laser chip 900 to meet overall power consumption requirements. The laser chip 900 employs a differential drive mode to effectively reduce power consumption. The differential drive modulation signals enter the electroabsorption modulation region separately; these two differential signals have the same amplitude and frequency but opposite phase. Compared to single-ended drive chips, differential drive offers advantages such as stronger noise immunity, longer transmission distance, and lower power consumption.

[0232] In some embodiments, the first electroabsorption modulation region 940 includes a first electrode portion and a second electrode portion. The first electrode portion can be a P-plane electrode, and the second electrode portion can be an N-plane electrode. The first electrode portion and the second electrode portion are arranged in a coplanar electrode configuration to reduce the parasitic capacitance between the electrodes of the modulation region.

[0233] In some embodiments, the light-emitting region 910 shares a substrate with each electroabsorption modulation region. The substrate is a semi-insulating substrate to prevent the drive modulation signal connected to the electroabsorption modulation region from being interfered with by the light-emitting region 910, thus ensuring smooth differential driving.

[0234] In some embodiments, since the substrate is a semi-insulating substrate, the N-type electrode in the light-emitting region 910 and the second electrode portion of the first electroabsorption modulation region 940 cannot be disposed on the back side of the substrate 911. Therefore, the N-type electrode and the P electrode in the light-emitting region 910 are coplanar electrodes. The first electrode portion and the second electrode portion in the first electroabsorption modulation region 940 are also coplanar electrodes.

[0235] In some embodiments, the first electroabsorption modulation region 940 may include a first radio frequency electrode RF+. The first radio frequency electrode RF+ is electrically connected to the first electrode portion and inputs a first differential drive modulation signal to the first electroabsorption modulation region 940.

[0236] In some embodiments, the first electroabsorption modulation region 940 may include a second radio frequency electrode RF-. The first radio frequency electrode RF+ and the second radio frequency electrode RF- constitute a differential drive electrode. The second radio frequency electrode RF- is electrically connected to the second electrode portion to input a second differential drive modulation signal to the first electroabsorption modulation region 940. The second differential drive modulation signal and the first differential drive modulation signal constitute a differential pair.

[0237] In some embodiments, the first electroabsorption modulation region 940 may include a first DC electrode DC+. The first DC electrode DC+ is electrically connected to the first electrode portion to input a first differential reverse bias voltage to the first electroabsorption modulation region 940.

[0238] In some embodiments, the first electroabsorption modulation region 940 may include a second DC electrode DC-. The first DC electrode DC+ and the second DC electrode DC- constitute a differential reverse bias electrode. The second DC electrode DC- is electrically connected to the second electrode portion to input a second differential reverse bias voltage to the first electroabsorption modulation region 940. The second differential reverse bias voltage and the first differential reverse bias voltage form a differential pair.

[0239] In some embodiments, when the first electroabsorption modulation region 940 is operational, a first differential driving modulation signal and a second differential driving modulation signal with opposite phases are simultaneously applied to the first electrode portion and the second electrode portion, forming a differential driving mode. Based on the electro-optic modulation effect, light entering the active region of the first electroabsorption modulation region 940 is modulated by the differential driving modulation signal to generate an optical signal carrying information. Signal modulation is performed using a coplanar electrode differential driving method, thereby reducing power consumption.

[0240] In some embodiments, the first radio frequency electrode RF+ is electrically connected to the first electrode portion. The second radio frequency electrode RF- is electrically connected to the second electrode portion.

[0241] In some embodiments, if the first DC electrode DC+ is electrically connected to the first radio frequency electrode RF+, then the first DC electrode DC+ is electrically connected to the first electrode portion.

[0242] In some embodiments, if the second DC electrode DC- is electrically connected to the second radio frequency electrode RF-, then the second DC electrode DC- is electrically connected to the second electrode portion.

[0243] In some embodiments, the differential driving mode of the second electroabsorption modulation region 950, the third electroabsorption modulation region 960, and the fourth electroabsorption modulation region 970 is the same as that of the first electroabsorption modulation region 940, and will not be elaborated further.

[0244] In some embodiments, the first electroabsorption modulation region 940 and the second electroabsorption modulation region 950 are offset and disposed on one side of the light-emitting region 910 to deploy their respective differential driving electrodes and differential reverse bias electrodes.

[0245] In some embodiments, the third electroabsorption modulation region 960 and the fourth electroabsorption modulation region 970 are offset and disposed on the other side of the light-emitting region 910 to deploy their respective differential driving electrodes and differential reverse bias electrodes.

[0246] In some embodiments, the laser chip 900 outputs multiple optical signals. The first optical signal is output from the emitting end of the first electroabsorption modulation region 940, the second optical signal is output from the emitting end of the second electroabsorption modulation region 950, the third optical signal is output from the emitting end of the third electroabsorption modulation region 960, and the fourth optical signal is output from the emitting end of the fourth electroabsorption modulation region 970. The laser chip 900 has four emitting ports on its emitting end face, meaning the four emitting ports are located on the same side. Therefore, each optical signal generated by modulation is output along the same side of the laser chip 900, and coupled to the fiber array 430 along the same side, achieving multi-channel optical array output.

[0247] In some embodiments, there is a mismatch in the optical field mode size between the laser chip 900 and the fiber array 430, resulting in coupling loss between them. For example, the output spot size of the laser chip 900 is smaller than the coupled spot size of the fiber array 430.

[0248] In some embodiments, multiple couplers may be provided between the laser chip 900 and the optical fiber array 430 to achieve mode switching. In some embodiments, multiple couplers may be integrated inside the laser chip 900 to achieve mode switching.

[0249] In some embodiments, an end-face coupler is provided on the output optical path of each electro-absorption modulation region to perform mode conversion, thereby amplifying the optical signal spot size output by the electro-absorption modulation region, thereby increasing the coupling efficiency with the fiber array 430, reducing coupling loss, and realizing relatively low-loss coupling between the laser chip and optical fibers of different sizes. Thus, there is no need to set a separate converging lens between the laser chip 900 and the fiber array 430, and the laser chip 900 and the fiber array 430 can be directly end-face coupled.

[0250] In some embodiments, the laser chip 900 integrates various end-face couplers, enabling low-loss coupling with optical fibers of different diameters in waveguides with relatively wide and short waveguide tips.

[0251] In some embodiments, the structure of one of the couplers may be referred to Figure 11a The cross-sectional structure of the coupler is shown in the following description of the structure of the first coupler 987.

[0252] In some embodiments, a first coupler 987 is provided on the optical path of the first electroabsorption modulation region 940 to perform mode conversion on the first optical signal, thereby achieving low-loss coupling between the first optical signal and the fiber array 430. One end of the first coupler 987 is optically connected to the first electroabsorption modulation region 940, and the other end is optically connected to the fiber array 430.

[0253] In some embodiments, a second coupler 988 is provided on the optical path of the second electroabsorption modulation region 950 to perform mode conversion on the second optical signal, thereby achieving low-loss coupling between the second optical signal and the fiber array 430. One end of the second coupler 988 is optically connected to the second electroabsorption modulation region 950, and the other end is optically connected to the fiber array 430.

[0254] In some embodiments, a third coupler 989 is provided on the optical path of the third electroabsorption modulation region 960 to perform mode conversion on the third optical signal, thereby achieving low-loss coupling between the third optical signal and the fiber array 430. One end of the third coupler 989 is optically connected to the third electroabsorption modulation region 960, and the other end is optically connected to the fiber array 430.

[0255] In some embodiments, a fourth coupler 989a is provided on the optical path of the fourth electroabsorption modulation region 970 to perform mode conversion on the fourth optical signal, thereby achieving low-loss coupling between the fourth optical signal and the fiber array 430. One end of the fourth coupler 989a is optically connected to the fourth electroabsorption modulation region 970, and the other end is optically connected to the fiber array 430.

[0256] In some embodiments, a first coupler 987 is located between a first electroabsorption modulation region 940 and the light-emitting end face of a laser chip 900. A second coupler 988 is located between a second electroabsorption modulation region 950 and the light-emitting end face of a laser chip 900. A third coupler 989 is located between a third electroabsorption modulation region 960 and the light-emitting end face of a laser chip 900. A fourth coupler 989a is located between a fourth electroabsorption modulation region 970 and the light-emitting end face of a laser chip 900. The coupled optical signals are output along the light-emitting end face of the laser chip 900 and coupled into the fiber array 430.

[0257] In some embodiments, the first coupler 987, the second coupler 988, the third coupler 989, and the fourth coupler 989a may have the same structure. The following embodiments use the first coupler 987 as an example to illustrate its structure.

[0258] Figure 11a This is a diagram of a first coupler structure according to some embodiments. Figure 11b This is a cross-sectional view of a first coupler according to some embodiments. Figure 11a and Figure 11b As shown, in some embodiments, a first coupler 987 is provided on the optical path of the first electroabsorption modulation region 940. The first coupler 987 is used to perform mode conversion on the first optical signal output from the first electroabsorption modulation region 940, amplify its spot size, and couple the first optical signal with amplified spot size into the fiber array 430, thereby realizing low-loss coupling between the laser chip 900 and the fiber array 430.

[0259] In some embodiments, the first coupler 987 may include a substrate 9871. The substrate 9871 is a semi-insulating substrate wafer.

[0260] In some embodiments, the first coupler 987 may include an N-InP layer 9872. The N-InP layer 9872 is located above the substrate 9871. The N-InP layer 9872 is an N-type doped InP layer.

[0261] In some embodiments, the first coupler 987 may include a P-InP layer 9873. The P-InP layer 9873 is located above the N-InP layer 9872. The P-InP layer 9873 is a P-type doped InP layer.

[0262] In some embodiments, the first coupler 987 may include a waveguide layer 9874. The waveguide layer 9874 is buried within a P-InP layer 9873. The waveguide layer 9874 is a passive transmission waveguide layer.

[0263] In some embodiments, the refractive indices of both the N-InP layer 9872 and the P-InP layer 9873 are less than the refractive index of the waveguide layer 9874, thereby confining the light field within the waveguide layer 9874 for transmission.

[0264] Figure 11c This is a schematic diagram of a waveguide layer planar structure according to some embodiments. Figure 11cAs shown, in some embodiments, waveguide layer 9874 includes a linearly graded region 9876. The linearly graded region 9876 can be a linearly graded region. Non-graded waveguide regions are connected to both ends of the linearly graded region 9876, one of which is optically connected to the first electro-absorption modulation region 940, and the other is optically connected to the fiber array 430. The width of the non-graded waveguide region optically connected to the first electro-absorption modulation region 940 is greater than the width of the non-graded waveguide region optically connected to the fiber array 430.

[0265] In some embodiments, in the linear gradient region 9876, the waveguide width of the waveguide layer 9874 gradually narrows with the direction of optical field propagation. As the waveguide width narrows, the optical confinement factor of the waveguide layer 9874 decreases, the waveguide layer 9874's ability to confine the optical field weakens, and the light spot is squeezed into the N-InP layer 9872 and the P-InP layer 9873, thereby increasing the light spot size, improving the optical field mode matching with the fiber array 430, and enabling the first optical signal to be coupled into the fiber array 430 with low loss.

[0266] In some embodiments, when coupling the first optical signal to the fiber array 430, the output position of the first coupler 987 should have a narrow waveguide width. Simultaneously, the linear gradient region 9876 will also be relatively long.

[0267] In some embodiments, a narrower waveguide width increases the difficulty of the etching process, while a longer linear gradient region 9876 results in a smaller divergence angle that satisfies thermal transmission requirements.

[0268] like Figure 11a and Figure 11b As shown, in some embodiments, the first coupler 987 may include a doped layer 9875. The doped layer 9875 is located within the N-InP layer 9872. The refractive index of the doped layer 9875 is greater than that of the N-InP layer 9872. The doped layer 9875 is a thin layer formed of InGaAsP material. Exemplarily, the thickness of the doped layer 9875 is less than the thickness of the N-InP layer 9872. For example, the thickness of the doped layer 9875 may be 60 nm.

[0269] In some embodiments, when the waveguide width of the linear gradient region 9876 is large, the role of the doped layer 9875 is limited. As the waveguide width narrows, the ability to confine the light spot weakens, the light spot becomes larger, and the optical field boundary extends to the doped layer 9875. The doped layer 9875 has a high refractive index, which helps to distribute more optical field in this layer structure, further enlarging the light spot size and increasing the coupling efficiency between the first optical signal and the fiber array 430.

[0270] In some embodiments, with the same waveguide width, the presence of the doped layer 9875 results in a larger spot size compared to when the doped layer 9875 is not present. Therefore, when forming the same spot size, based on the doped layer 9875, the required waveguide width at the output position is narrower, reducing the dependence on waveguide width, lowering the difficulty of waveguide etching, and overcoming the technical barrier of more difficult etching processes for narrower waveguide widths.

[0271] In some embodiments, the refractive index relationship among waveguide layer 9874, doped layer 9875, P-InP layer 9873, and N-InP layer 9872 can be: waveguide layer 9874 > doped layer 9875 > P-InP layer 9873 > N-InP layer 9872. For example, at the same doping concentration, P-InP layer 9873 is greater than N-InP layer 9872.

[0272] In some embodiments, the refractive index of the doped layer 9875 is greater than that of the P-InP layer 9873. The higher refractive index of the doped layer 9875 helps to distribute more light field in the layer structure, further amplifying the spot size. The refractive index of the doped layer 9875 is less than that of the waveguide layer 9874, allowing the main light field to be distributed more in the waveguide layer 9874 for transmission, which helps to reduce transmission loss.

[0273] In some embodiments, the P-InP layer 9873 has a high refractive index, and the waveguide layer 9874 is buried within the P-InP layer 9873, which helps to confine the light field within the waveguide layer 9874 for transmission and reduce transmission loss.

[0274] In some embodiments, by forming a doped layer 9875 in the N-InP layer 9872, the doped layer 9875 has a high refractive index, which helps to distribute more light field in the layer structure and further enlarge the spot size. Therefore, when forming the same spot size, the waveguide width required is smaller due to the setting of the doped layer 9875, which reduces the dependence on the waveguide width and reduces the difficulty of the waveguide etching process.

[0275] Figure 11d This is a schematic diagram of another waveguide layer planar structure according to some embodiments. For example... Figure 11d As shown, in some embodiments, waveguide layer 9874 includes a nonlinear gradient region 9877. One end of the nonlinear gradient region 9877 is connected to a first non-gradient region 9878, and the other end is connected to a second non-gradient region 9879.

[0276] In some embodiments, the first non-gradient region 9878 faces the first electro-absorption modulation region 940, and the first non-gradient region 9878 is optically connected to the first electro-absorption modulation region 940 to receive the optical signal output by the first electro-absorption modulation region 940.

[0277] In some embodiments, the second non-gradient region 9879 faces the fiber array 430 and is optically connected to the fiber array 430 to transmit the mode-converted optical signal into the fiber array 430.

[0278] In some embodiments, the waveguide width of the first non-gradient region 9878 depends on the single-mode conditions of the laser chip 900, and the waveguide width of the second non-gradient region 9879 depends on the coupling efficiency with the fiber array 430. For example, the waveguide width of the first non-gradient region 9878 is greater than the waveguide width of the second non-gradient region 9879.

[0279] In some embodiments, a nonlinear gradient region 9877 connects the first non-gradient region 9878 and the second non-gradient region 9879. In the nonlinear gradient region 9877, the waveguide width gradually changes from the first non-gradient region 9878 to the waveguide width of the second non-gradient region 9879. The waveguide width connecting the nonlinear gradient region 9877 to the first non-gradient region 9878 is greater than the waveguide width connecting the nonlinear gradient region 9877 to the second non-gradient region 9879.

[0280] In some embodiments, the nonlinear gradient region 9877 employs a nonlinear gradient region. The narrower the waveguide width, the more drastic the change in the optical field divergence angle with the waveguide width. Therefore, when the waveguide width is wider, the change can be faster, while when the waveguide width is narrower, the change should be slower to ensure fundamental mode coupling efficiency and avoid exciting higher-order modes. In this case, the objective can be achieved with a relatively short nonlinear gradient region 9877 length.

[0281] In some embodiments, the outer contour of the nonlinear gradient region 9877 is an arc, with one side being the first arc 9771 and the other side being the second arc 9772. Exemplarily, the first arc 9771 is a concave arc, recessed towards the waveguide center. The second arc 9772 is a convex arc, protruding towards the waveguide center. Along the direction from the first non-gradient region 9878 to the second non-gradient region 9879, the waveguide width between the first arc 9771 and the second arc 9772 gradually decreases. The waveguide width between the first arc 9771 and the second arc 9772 tends to be the same as the waveguide width of the second non-gradient region. This ensures that the waveguide width changes rapidly when it is large and slowly when it is narrow, thereby ensuring the fundamental mode coupling efficiency and avoiding the excitation of higher-order modes. The thermal insulation length of the nonlinear gradient region 9877 is shortened, effectively reducing the overall length of the first coupler 940.

[0282] Figure 12 This is a cross-sectional structural diagram of a light-emitting region according to some embodiments. Figure 13 This is a three-dimensional structural diagram of a light-emitting area according to some embodiments. For example... Figure 12 and Figure 13As shown, in some embodiments, in the light-emitting region 910, the first end and the second end, which are arranged opposite to each other, emit light respectively. The emitted light does not carry information and is to be modulated.

[0283] In some embodiments, a bias current is provided to the light-emitting region 910, and the light-emitting region 910 emits light under the action of the bias current.

[0284] In some embodiments, the light-emitting region 910 may include a substrate 911.

[0285] In some embodiments, the light-emitting region 910 may include an N-InP layer 912. The N-InP layer 912 is located above the substrate 911. The N-InP layer 912 is an N-type doped InP layer. The N-InP layer 912 primarily outputs N-type carriers.

[0286] In some embodiments, the light-emitting region 910 may include a first active layer 913. The first active layer 913 is located above the N-InP layer 912. The first active layer 913 employs a multi-quantum-well structure. The first active layer 913 is configured to generate photons by recombination of P-type carriers and N-type carriers. The N-type carriers originate from the N-InP layer 912.

[0287] In some embodiments, the light-emitting region 910 may include a grating layer 914. The grating layer 914 is located above the first active layer 913.

[0288] In some embodiments, the light-emitting region 910 may include a P-InP layer 915. The P-InP layer 915 is located above the grating layer 914. The P-InP layer 915 is a P-type doped InP layer. The P-InP layer 915 primarily outputs P-type carriers. The P-InP layer 915 inputs P-type carriers to the first active layer 913.

[0289] In some embodiments, within the first active layer 913, stimulated emission causes discrete P-type and N-type carrier pairs to recombine and generate photons, thereby converting injected carriers into photons. These photons are reflected by the resonant cavity or distributed feedback grating to form positive feedback, generating laser light. By changing the current injected into the grating layer 914, the effective refractive index of the grating layer 914 can be altered, thereby changing the laser resonant lasing wavelength and achieving output at a specific wavelength. Light without signal carrying is output from both ends of the first active layer 913.

[0290] In some embodiments, to ensure that the light output power of the two ends of the first active layer 913 is consistent, the grating layer 914 can be a phase-shift grating or a CPM grating, etc.

[0291] In some embodiments, the light-emitting region 910 may include a P-type electrode 916 and an N-type electrode 917. Both are coplanar electrodes. The P-type electrode 916 and the N-type electrode 917 are electrically connected to a forward bias current source for power supply.

[0292] Figure 14 This is a partial cross-sectional view of a laser chip according to some embodiments. Figure 14 For the appendix Figure 10a The cross-sectional structure corresponding to section line A. For example... Figure 14 As shown, in some embodiments, the second end of the light-emitting region 910 is connected to a second transmission waveguide 982, which reflects the second light beam emitted from the second end of the light-emitting region 910 back to the first end.

[0293] In some embodiments, the light-emitting region 910 and the second transmission waveguide 982 may employ the same waveguide structure. In the light-emitting region 910, the first active layer 913 employs a multi-quantum-well structure for signal modulation. In this layer, the corresponding structure of the second transmission waveguide 982 is a transmission layer 9822, which employs a waveguide material with low transmission loss to reduce transmission loss.

[0294] In some embodiments, the P-type electrode 916 is relatively long, covering the light-emitting area 910 and the corresponding surface of the second transmission waveguide 982.

[0295] In some embodiments, a SiO2 layer 919a is provided below the P-type electrode 916. A window is opened on the surface of the P-InP layer 915 to remove the corresponding SiO2 layer, thereby ensuring the conductivity between the P-type electrode 916 and the first active layer 913. In the region corresponding to the second transmission waveguide 982, a SiO2 layer 919a is provided below the P-type electrode 916 to achieve insulation.

[0296] Figure 15 A first electroabsorption modulation region profile structure according to some embodiments Figure 1 . Figure 15 For the appendix Figure 10a The cross-sectional structure corresponding to section line B. For example... Figure 15 As shown, in some embodiments, the first electroabsorption modulation region 940 employs a differential drive mode.

[0297] In some embodiments, the first electroabsorption modulation region 940 includes a substrate 941.

[0298] In some embodiments, the first electroabsorption modulation region 940 includes an N-InP layer 942. The N-InP layer 942 is located above the substrate 941. The N-InP layer 942 is an N-type doped InP layer. The N-InP layer 942 primarily outputs N-type carriers.

[0299] In some embodiments, the first electroabsorption modulation region 940 includes a second active layer 943. The second active layer 943 is located above the N-InP layer 942. The second active layer 943 employs a multi-quantum-well structure.

[0300] In some embodiments, the first electroabsorption modulation region 940 includes a P-InP layer 944. The P-InP layer 944 is located above the second active layer 943. The P-InP layer 944 is a P-type doped InP layer. The P-InP layer 944 primarily outputs P-type carriers. The P-InP layer 944 inputs P-type carriers to the second active layer 943, and the N-InP layer 942 inputs N-type carriers to the second active layer 943, thereby inputting a signal to the first electroabsorption modulation region 940.

[0301] In some embodiments, the first electroabsorption modulation region 940 includes a first electrode portion 945. The first electrode portion 945 is located above the P-InP layer 944. Exemplarily, the first electrode portion 945 is a P-type electrode.

[0302] In some embodiments, the first electroabsorption modulation region 940 includes a second electrode portion 946. The second electrode portion 946 and the first electrode portion 945 are coplanar electrodes. Exemplarily, the second electrode portion 946 is an N-type electrode.

[0303] In some embodiments, the first electrode portion 945 and the second electrode portion 946 are respectively electrically connected to a reverse bias electric field.

[0304] In some embodiments, the first electroabsorption modulation region 940 includes a first radio frequency electrode 9471. The first radio frequency electrode 9471 is electrically connected to the first electrode portion 945 to input a first differential drive modulation signal to the second active layer 943.

[0305] In some embodiments, a trench is provided between the first radio frequency electrode 9471 and the waveguide structure of the first electroabsorption modulation region 940 to achieve electrical isolation and ensure the quality of radio frequency signal transmission. A first electrical connection bridge 9481 is electrically connected between the first radio frequency electrode 9471 and the first electrode portion 945 to establish an electrical connection between the first radio frequency electrode 9471 and the first electrode portion 945.

[0306] Figure 16 A first electroabsorption modulation region profile structure according to some embodiments Figure 2 . Figure 16 For the appendix Figure 10a The cross-sectional structure corresponding to section line C. For example... Figure 16 As shown, in some embodiments, the first electroabsorption modulation region 940 employs a differential drive mode.

[0307] In some embodiments, the first electroabsorption modulation region 940 includes a second radio frequency electrode 9472. The second radio frequency electrode 9472 is electrically connected to the second electrode portion 946 to input a second differential drive modulation signal to the second active layer 943.

[0308] In some embodiments, a trench is provided between the second RF electrode 9472 and the waveguide structure of the first electroabsorption modulation region 940 to achieve electrical isolation and ensure the quality of RF signal transmission. A second electrical connection bridge 9482 is electrically connected between the second RF electrode 9472 and the second electrode portion 946 to establish an electrical connection between the second RF electrode 9472 and the second electrode portion 946.

[0309] In some embodiments, the first electrical connection bridge 9481 and the second electrical connection bridge 9482 may each be an air bridge. An air bridge utilizes air, which has a low dielectric constant, as the dielectric, reducing parasitic capacitance. Due to the low dielectric constant of air, signal transmission speed in an air bridge is relatively fast, with less loss. The structural design of an air bridge can optimize the signal transmission path, reduce signal reflection and scattering during transmission, thereby improving signal transmission efficiency and quality.

[0310] In some embodiments, the first electrical connection bridge 9481 and the second electrical connection bridge 9482 are integrated inside the chip, and since they are chip-level structures, they are different from the gold wire bonding method.

[0311] Figure 17 A first electroabsorption modulation region profile structure according to some embodiments Figure 3 . Figure 17 For the appendix Figure 10a The cross-sectional structure corresponding to section line D. For example... Figure 17 As shown, in some embodiments, the first electroabsorption modulation region 940 employs a differential drive mode.

[0312] In some embodiments, the first electroabsorption modulation region 940 includes a first DC electrode 9473.

[0313] In some embodiments, the first DC electrode 9473 is electrically connected to the first RF electrode 9471. The first RF electrode 9471 is electrically connected to the first electrode portion 945, and the first DC electrode 9473 is electrically connected to the first electrode portion 945, thus inputting a first differential reverse bias voltage to the second active layer 943.

[0314] In some embodiments, a first connection resistor 9491 is provided between the first DC electrode 9473 and the first RF electrode 9471 to establish an electrical connection between them. The first connection resistor 9491 is an on-chip integrated resistor.

[0315] In some embodiments, an electrical isolation trench is formed between the first radio frequency electrode 9471 and the first DC electrode 9473 to prevent crosstalk between the radio frequency signal and the DC signal. A third electrical connection bridge 9483 is formed above the electrical isolation trench.

[0316] In some embodiments, a first connection resistor 9491 and a third electrical connection bridge 9483 are connected between the first radio frequency electrode 9471 and the first DC electrode 9473 to realize the electrical connection between the first radio frequency electrode 9471 and the first DC electrode 9473.

[0317] In some embodiments, one end of the first radio frequency electrode 9471 is connected to a first connection resistor 9491, one end of the first connection resistor 9491 is connected to a third electrical connection bridge 9483, and one end of the third electrical connection bridge 9483 is connected to a first DC electrode 9473, thereby realizing the electrical connection between the first radio frequency electrode 9471 and the first DC electrode 9473, and further realizing the electrical connection between the first DC electrode 9473 and the first electrode portion 945.

[0318] Figure 18 A first electroabsorption modulation region profile structure according to some embodiments Figure 4 . Figure 18 For the appendix Figure 10a The cross-sectional structure corresponding to section line E. For example... Figure 18 As shown, in some embodiments, each electroabsorption modulation region adopts a differential driving mode. Therefore, the first electroabsorption modulation region 940 adopts a differential driving mode. The following description uses the first electroabsorption modulation region 940 as an example to illustrate the differential driving implementation.

[0319] In some embodiments, the first electroabsorption modulation region 940 includes a second DC electrode 9474.

[0320] In some embodiments, the second DC electrode 9474 is electrically connected to the second RF electrode 9472. The second RF electrode 9472 is electrically connected to the second electrode portion 946, and the second DC electrode 9474 is electrically connected to the second electrode portion 946, thus inputting a second differential reverse bias voltage to the second active layer 943.

[0321] In some embodiments, a second connection resistor 9492 is provided between the second RF electrode 9472 and the second DC electrode 9474 to establish an electrical connection between them. The second connection resistor 9492 is an on-chip integrated resistor.

[0322] In some embodiments, an electrical isolation trench is formed between the second radio frequency electrode 9472 and the second DC electrode 9474 to prevent crosstalk between the radio frequency signal and the DC signal. A fourth electrical connection bridge 9484 is formed above the electrical isolation trench.

[0323] In some embodiments, a second connection resistor 9492 and a fourth electrical connection bridge 9484 are connected between the second radio frequency electrode 9472 and the second DC electrode 9474, thereby realizing the electrical connection between the second radio frequency electrode 9472 and the second DC electrode 9474.

[0324] In some embodiments, one end of the second radio frequency electrode 9472 is connected to a second connection resistor 9492, one end of the second connection resistor 9492 is connected to a fourth electrical connection bridge 9484, and one end of the fourth electrical connection bridge 9484 is connected to a second DC electrode 9474, thereby realizing the electrical connection between the second radio frequency electrode 9472 and the second DC electrode 9474, and further realizing the electrical connection between the second DC electrode 9474 and the second electrode portion 946.

[0325] In some embodiments, the first connecting resistor 9491 and the second connecting resistor 9492 are on-chip thin-film resistors, which can be implemented using semiconductor materials such as TaN or TiN. The sheet resistance is adjusted by the thickness, and the required resistance value is adjusted by the length and width. On-chip integrated resistors can reduce wire bonding length and decrease the impact of parasitic parameters on the high-speed performance of the chip.

[0326] In some embodiments, each electrical connection bridge may adopt an air bridge structure to reduce parasitic parameters and improve the high-speed characteristics of the chip.

[0327] In some embodiments, the first radio frequency electrode 9471, the second radio frequency electrode 9472, the first DC electrode 9473, and the second DC electrode 9474 are respectively disposed on the surface of the laser chip 900. For example... Figure 10a As shown, the first DC electrode 9473 is located on one side of the first RF electrode 9471, and the second RF electrode 9472 is located on the other side of the first RF electrode 9471. The first DC electrode 9473, the first RF electrode 9471, and the second RF electrode 9472 are arranged sequentially. The first RF electrode 9471 is located on one side of the second RF electrode 9472, and the second DC electrode 9474 is located on the other side of the second RF electrode 9472. The first DC electrode 9473, the first RF electrode 9471, the second RF electrode 9472, and the second DC electrode 9474 are arranged sequentially on the surface of the laser chip. This linear arrangement occupies a small area, which is beneficial for arranging the electrodes of the four electro-absorption modulation regions on the surface of the laser chip, thereby meeting the differential drive mode requirements of the four electro-absorption modulation regions.

[0328] In some embodiments, a method for fabricating a laser chip is provided, comprising: growing an N-InP layer along the surface of a substrate, growing a quantum well layer upward along the surface of the N-InP layer, and photolithographically fabricating a grating on the surface of the quantum well layer.

[0329] Then, the quantum well layer and grating of a predetermined width are etched away, and the remaining portion forms the first active layer 913 and grating layer 914 in the light-emitting region. Quantum well material is epitaxially grown along the first active layer 913 and grating layer 914 to subsequently fabricate the active layer of the electro-absorption modulation region. Waveguide layer material in the transmission waveguides is then grown along the quantum well material to subsequently fabricate each transmission waveguide. A large-area P-InP layer is grown along the current surface.

[0330] The quantum well material is etched to form the active layers in the first electro-absorption modulation region 940, the second electro-absorption modulation region 950, the third electro-absorption modulation region 960, and the fourth electro-absorption modulation region 970. The waveguide layer material is etched to form the first transmission waveguide 981, the second transmission waveguide 982, the third transmission waveguide 983, the fourth transmission waveguide 984, the fifth transmission waveguide 985, and the sixth transmission waveguide 986.

[0331] P-type electrodes 916, N-type electrodes 917, a first bias electrode 918, and a second bias electrode 919 are formed in the light-emitting region by metal deposition. A first electrode portion 945, a second electrode portion 946, a first radio frequency electrode 9471, a second radio frequency electrode 9472, a first DC electrode 9473, and a second DC electrode 9474 are also formed for each electro-absorption modulation region, facilitating the implementation of a differential driving mode. A first electrical connection bridge is formed between the first radio frequency electrode 9471 and the first electrode portion 945 corresponding to the electro-absorption modulation region, electrically connecting the first radio frequency electrode 9471 and the first electrode portion 945.

[0332] A second electrical bridge is formed between the second RF electrode 9472 and the second electrode portion 946 corresponding to the electroabsorption modulation region, electrically connecting the second RF electrode 9472 and the second electrode portion 946. A first connecting resistor and a third electrical bridge are formed between the first RF electrode 9471 and the first DC electrode 9473, electrically connecting the first RF electrode 9471 and the first DC electrode 9473, and further electrically connecting the first DC electrode 9473 and the first electrode portion 945. A second connecting resistor and a fourth electrical bridge are formed between the second RF electrode 9472 and the second DC electrode 9474, electrically connecting the second RF electrode 9472 and the second DC electrode 9474, and further electrically connecting the second DC electrode 9474 and the second electrode portion 946.

[0333] In some embodiments, a first coupler 987 is etched in the light output path of the first electroabsorption modulation region 940, a second coupler 988 is etched in the light output path of the second electroabsorption modulation region 950, a third coupler 989 is etched in the light output path of the third electroabsorption modulation region 960, and a fourth coupler 989a is etched in the light output path of the fourth electroabsorption modulation region 970.

[0334] Figure 19This is a structural diagram of a laser component according to some embodiments. Figure 20 This is an exploded view of a laser assembly according to some embodiments. Figure 19 and Figure 20 As shown, in some embodiments, the laser assembly 410 includes a laser chip 900 and a substrate 420. A circuit pattern is formed on the surface of the substrate 420 to establish electrical connections with the circuit board 300 and the laser chip 900, respectively.

[0335] In some embodiments, the surface of the laser chip 900 is wire-connected to the surface of the substrate 420 to achieve electrical connection between the laser chip 900 and the substrate 420.

[0336] In some embodiments, when the substrate 420 is made of different materials, the laser chip 900 and the substrate 420 have different positional relationships. For example, when the substrate 420 is made of a first material, such as a ceramic substrate, the laser chip 900 is located on the surface of the substrate 420, and there is a height difference between the surface of the laser chip 900 and the surface of the substrate 420, resulting in a relatively long bonding wire between them. For example, when the substrate 420 is made of a second material, such as a silicon substrate, the laser chip 900 can be embedded inside the substrate 420, so that the surface of the laser chip 900 is flush with the surface of the substrate 420, shortening the bonding wire length between them, which is beneficial for improving high-frequency signal transmission performance and increasing signal bandwidth.

[0337] In some embodiments, when the substrate 420 is made of a second material, such as a silicon substrate, a groove 421 is formed on the surface of the substrate 420. The laser chip 900 is embedded in the groove 421 to ensure that the surface of the laser chip 900 is flush with the surface of the substrate 420, thereby shortening the wire bonding length between them.

[0338] In some embodiments, the laser chip 900 includes multiple electro-absorption modulation regions to modulate multiple optical signals and achieve multi-channel optical signal array output.

[0339] In some embodiments, the laser chip 900 includes a first electro-absorption modulation region 940, a second electro-absorption modulation region 950, a third electro-absorption modulation region 960, and a fourth electro-absorption modulation region 970, which modulate the four-channel light signal to achieve four-channel array output.

[0340] In some embodiments, the first electroabsorption modulation region 940, the second electroabsorption modulation region 950, the third electroabsorption modulation region 960 and the fourth electroabsorption modulation region 970 respectively adopt differential driving mode to reduce power consumption.

[0341] In some embodiments, the first electroabsorption modulation region 940 includes a first radio frequency electrode 9471, a second radio frequency electrode 9472, a first DC electrode 9473, and a second DC electrode 9474. These four electrodes are disposed on the surface of the laser chip 900. Correspondingly, the four electrodes of the remaining electroabsorption modulation regions are also disposed on the surface of the laser chip 900. Exemplarily, these electrodes are disposed side by side on the surface of the laser chip 900.

[0342] In some embodiments, a light-emitting region 910 is formed at one end of the laser chip 900, emitting multiple beams of light without carrying information. Multiple modulation regions are formed on one side of the light-emitting region 910. In each modulation region, one of the beams of light without carrying information modulates a signal to generate an optical signal. Multiple optical signals can be generated by modulation through the multiple modulation regions. An output port region 900d is formed on one side of the multiple modulation regions. The output port region 900d includes multiple output ports, and the modulated optical signals are output along the corresponding output ports. The output port region 900d is positioned opposite the light-emitting region 910, with the multiple modulation regions located between the light-emitting region 910 and the output port region 900d. The multiple optical signals generated by the modulation of the multiple modulation regions are output along the output port region 900d. Thus, the laser chip can output multiple optical signals, achieving array-based light output, improving chip integration, and increasing the transmission rate of the optical module. The multiple modulation regions include a first electroabsorption modulation region 940, a second electroabsorption modulation region 950, a third electroabsorption modulation region 960, and a fourth electroabsorption modulation region 970.

[0343] Figure 21 A surface structure of a laser component according to some embodiments Figure 1 , Figure 22 This is a surface layout structure diagram of a laser component according to some embodiments. For example... Figure 21 and Figure 22 As shown, in some embodiments, the surface of the substrate 420 has a circuit pattern to enable electrical connection between the substrate 420 and the circuit board 300 and the laser chip 900, respectively.

[0344] In some embodiments, two differential bias circuits are added to the output circuit of the electroabsorption modulation region to improve high-frequency performance and reduce the overall design size of the chip.

[0345] In some embodiments, the dashed rectangle A on the surface of the laser chip 900 marks the area corresponding to the first electroabsorption modulation region 940. The dashed rectangle B marks the area corresponding to the second electroabsorption modulation region 950. The dashed rectangle C marks the area corresponding to the third electroabsorption modulation region 960. The dashed rectangle D marks the area corresponding to the fourth electroabsorption modulation region 970.

[0346] In some embodiments, the electrode circled by the dashed rectangle A is the first electrode group in the first electroabsorption modulation region 940. The first electrode group includes a first radio frequency electrode 9471, a second radio frequency electrode 9472, a first DC electrode 9473, and a second DC electrode 9474.

[0347] In some embodiments, the electrode circled by the dashed rectangle B is the second electrode group in the second electroabsorption modulation region 950. The composition of the second electrode group is the same as that of the first electrode group.

[0348] In some embodiments, the electrode circled by the dashed rectangle C is the third electrode group in the third electroabsorption modulation region 960. The third electrode group includes a third radio frequency electrode 9471a, a fourth radio frequency electrode 9472a, a third DC electrode 9473a, and a fourth DC electrode 9474a.

[0349] In some embodiments, the electrode circled by the dashed rectangle D is the fourth electrode group in the fourth electroabsorption modulation region 970. The composition of the fourth electrode group is the same as that of the first electrode group.

[0350] In some embodiments, the first radio frequency electrode 9471 is electrically connected to the first electrode portion 945. The second radio frequency electrode 9472 is electrically connected to the second electrode portion 946.

[0351] In some embodiments, the first DC electrode 9473 is electrically connected to the first radio frequency electrode 9471, and the first DC electrode 9473 is electrically connected to the first electrode portion 945. Exemplarily, a first connection resistor 9491 is provided between the first DC electrode 9473 and the first radio frequency electrode 9471.

[0352] In some embodiments, the second DC electrode 9474 is electrically connected to the second radio frequency electrode 9472, and the second DC electrode 9474 is also electrically connected to the second electrode portion 946. Exemplarily, a second connection resistor 9492 is provided between the second DC electrode 9474 and the second radio frequency electrode 9472.

[0353] In some embodiments, the substrate 420 surface is provided with differential drive signal lines corresponding to four electro-absorption modulation regions. Using differential traces can improve the mutual coupling characteristics during signal transmission, reduce dependence on ground, and increase signal bandwidth.

[0354] In some embodiments, the inner layer of the substrate 420 is provided with differential bias signal lines corresponding to four electroabsorption modulation regions to avoid crossing with differential drive signal lines, thereby avoiding interference of DC signals on the radio frequency signals and ensuring the quality of radio frequency signal transmission.

[0355] In some embodiments, a first region 900a, a second region 900b, and a third region 900c are formed on the surface of the laser chip 900. The first region 900a and the second region 900b are arranged adjacent to each other, and the first region 900a and the third region 900c are arranged opposite to each other. The light output port region 900d is arranged opposite to the second region 900b.

[0356] In some embodiments, the first region 900a is located on the side adjacent to the second region 900b, and the third region 900c is located on the other side adjacent to the second region 900b. The light output port region 900d is located on the opposite side of the second region 900b.

[0357] In some embodiments, the surface of the first region 900a is provided with a first electrode group in the first electroabsorption modulation region 940 and a second electrode group in the second electroabsorption modulation region 950.

[0358] In some embodiments, a first bias electrode and a second bias electrode are disposed on the surface of the second region 900b, and the first bias electrode and the second bias electrode are electrically connected to the light-emitting region to input a bias current to the light-emitting region.

[0359] In some embodiments, the surface of the third region 900c is provided with a third electrode group in the third electroabsorption modulation region 960 and a fourth second electrode group in the fourth electroabsorption modulation region 970.

[0360] In some embodiments, taking the first electroabsorption modulation region 940 as an example, a first differential drive signal line 4221 and a second differential drive signal line 4222 are formed on the surface of the substrate 420, and the two are electrically connected to the first electroabsorption modulation region 940 to input differential drive modulation signals to the first electroabsorption modulation region 940.

[0361] In some embodiments, one end of the first differential drive signal line 4221 is electrically connected to the circuit board 300, and the other end is electrically connected to the first radio frequency electrode 9471 to input the first differential drive modulation signal to the first electroabsorption modulation region 940.

[0362] In some embodiments, one end of the second differential drive signal line 4222 is electrically connected to the circuit board 300, and the other end is electrically connected to the second radio frequency electrode 9472 to input the second differential drive modulation signal to the first electroabsorption modulation region 940.

[0363] In some embodiments, a first signal pad 4231 and a second signal pad 4232 are provided on a surface of the substrate 420 adjacent to the laser chip 900, and a third signal pad 4233 and a fourth signal pad 4234 are provided on a surface of the substrate 420 adjacent to the circuit board 300.

[0364] In some embodiments, a first differential drive signal line 4221 is connected between the first signal pad 4231 and the third signal pad 4233. The first differential drive signal line 4221 is wire-connected to the first radio frequency electrode 9471, and the first radio frequency electrode 9471 is electrically connected to the first electrode portion 945, thereby inputting a first differential drive modulation signal to the first electroabsorption modulation region 940.

[0365] In some embodiments, a second differential drive signal line 4222 is connected between the second signal pad 4232 and the fourth signal pad 4234. The second differential drive signal line 4222 is wire-connected to the second radio frequency electrode 9472, and the second radio frequency electrode 9472 is electrically connected to the second electrode portion 946, thereby inputting a second differential drive modulation signal to the first electroabsorption modulation region 940.

[0366] In some embodiments, the first DC electrode 9473, the first RF electrode 9471, the second RF electrode 9472, and the second DC electrode 9474 are sequentially disposed on the surface of the laser chip. The linear arrangement occupies a small area, which is beneficial for arranging these electrodes of the four electro-absorption modulation regions on the surface of the laser chip, thereby meeting the differential driving mode requirements of the four electro-absorption modulation regions.

[0367] In some embodiments, to meet the differential driving mode requirements of the laser chip 900, a first signal pad 4231 is disposed on the surface of the substrate 420 and electrically connected to the first radio frequency electrode 9471. A second signal pad 4232 is disposed on one side of the first signal pad 4231 and electrically connected to the second radio frequency electrode 9471. A third signal pad 4233 and a fourth signal pad 4234 are disposed on the side near the circuit board 300 and electrically connected to the circuit board 300.

[0368] In some embodiments, a first differential drive signal line 4221 is connected between the first signal pad 4231 and the third signal pad 4233. The first differential drive signal line 4221 electrically connects the first radio frequency electrode 9471 and the circuit board 300, thereby inputting a first differential drive modulation signal to the first electroabsorption modulation region 940 through the first radio frequency electrode 9471.

[0369] In some embodiments, a second differential drive signal line 4222 is connected between the second signal pad 4232 and the fourth signal pad 4234. The second radio frequency electrode 9472 is electrically connected to the circuit board 300 through the second differential drive signal line 4222, thereby inputting a second differential drive modulation signal from the second radio frequency electrode 9472 to the first electroabsorption modulation region 940.

[0370] In some embodiments, to meet the differential drive mode requirements of the laser chip 900, the fifth signal pad 4241 is located on the other side of the first signal pad 4231 and is electrically connected to the first DC electrode 9473. The sixth signal pad 4243 is located on one side of the second signal pad 4232 and is electrically connected to the second DC electrode 9473. The seventh signal pad 4242 is located near the circuit board 300 and is electrically connected to the circuit board 300. The eighth signal pad 4244 is located on one side of the seventh signal pad 4242 and is electrically connected to the circuit board 300.

[0371] In some embodiments, a first differential bias signal line 4251 is connected between the fifth signal pad 4241 and the seventh signal pad 4242. The first differential bias signal line 4251 is electrically connected to the first DC electrode 9473 and the circuit board 300, thereby inputting a first differential reverse bias voltage to the first electroabsorption modulation region 940 through the first DC electrode 9473.

[0372] In some embodiments, a second differential bias signal line 4252 is connected between the sixth signal pad 4243 and the eighth signal pad 4244. The second differential bias signal line 4252 is electrically connected to the second DC electrode 9474 and the circuit board 300, thereby inputting a second differential reverse bias voltage into the first electroabsorption modulation region 940 through the second DC electrode 9474.

[0373] In some embodiments, the first DC electrode 9473 is located on one side of the first RF electrode 9471, and the second RF electrode 9472 is located on the other side of the first RF electrode 9471, thus the first DC electrode 9473, the first RF electrode 9471, and the second RF electrode 9472 are arranged sequentially. Alternatively, the first RF electrode 9471 is located on one side of the second RF electrode 9472, and the second DC electrode 9474 is located on the other side of the second RF electrode 9472, thus the first DC electrode 9473, the first RF electrode 9471, the second RF electrode 9472, and the second DC electrode 9474 are arranged sequentially on the surface of the laser chip 900. Correspondingly, the sixth signal pad 4243, the second signal pad 4232, the first signal pad 4231, and the fifth signal pad 4241 are arranged sequentially on the surface of the substrate 420. A linear arrangement occupies a small area, which is beneficial for distributing multiple electro-absorption modulation regions, thereby meeting the differential drive mode requirements of multiple electro-absorption modulation regions.

[0374] In some embodiments, a first ground pad 4235 is provided on one side of the third signal pad 4233, and a second ground pad 4236 is provided on one side of the fourth signal pad 4234. The third signal pad 4233 and the fourth signal pad 4234 are located between the first ground pad 4235 and the second ground pad 4236, thereby forming a GSSG differential drive mode, which is beneficial to improving the chip's noise immunity and reducing power consumption.

[0375] In some embodiments, a third differential drive signal line 4223 and a fourth differential drive signal line 4224 are formed on the surface of the substrate 420, and the two are electrically connected to the second electroabsorption modulation region 950 to input differential drive modulation signals to the second electroabsorption modulation region 950.

[0376] In some embodiments, one end of the third differential drive signal line 4223 is electrically connected to the circuit board 300, and the other end is electrically connected to the first radio frequency electrode of the second electroabsorption modulation region 950, so as to input the first differential drive modulation signal into the second electroabsorption modulation region 950.

[0377] In some embodiments, one end of the fourth differential drive signal line 4224 is electrically connected to the circuit board 300, and the other end is electrically connected to the second radio frequency electrode of the second electroabsorption modulation region 950, so as to input the second differential drive modulation signal into the second electroabsorption modulation region 950.

[0378] In some embodiments, a fifth differential drive signal line 4225 and a sixth differential drive signal line 4226 are formed on the surface of the substrate 420. Both are electrically connected to the third electroabsorption modulation region 960 to input differential drive modulation signals to the third electroabsorption modulation region 960.

[0379] In some embodiments, one end of the fifth differential drive signal line 4225 is electrically connected to the circuit board 300, and the other end is electrically connected to the first radio frequency electrode of the third electroabsorption modulation region 960, so as to input the first differential drive modulation signal into the third electroabsorption modulation region 960.

[0380] In some embodiments, one end of the sixth differential drive signal line 4226 is electrically connected to the circuit board 300, and the other end is electrically connected to the second radio frequency electrode of the third electroabsorption modulation region 960, so as to input the second differential drive modulation signal into the third electroabsorption modulation region 960.

[0381] In some embodiments, a seventh differential drive signal line 4227 and an eighth differential drive signal line 4228 are formed on the surface of the substrate 420. Both are electrically connected to the fourth electroabsorption modulation region 970 to input differential drive modulation signals to the fourth electroabsorption modulation region 970.

[0382] In some embodiments, one end of the seventh differential drive signal line 4227 is electrically connected to the circuit board 300, and the other end is electrically connected to the first radio frequency electrode of the fourth electroabsorption modulation region 970, so as to input the first differential drive modulation signal to the fourth electroabsorption modulation region 970.

[0383] In some embodiments, one end of the eighth differential drive signal line 4228 is electrically connected to the circuit board 300, and the other end is electrically connected to the second radio frequency electrode of the fourth electroabsorption modulation region 970, so as to input the second differential drive modulation signal to the fourth electroabsorption modulation region 970.

[0384] In some embodiments, the first differential drive signal line 4221 and the second differential drive signal line 4222 are located on the first side of the laser chip 900, and the third differential drive signal line 4223 and the fourth differential drive signal line 4224 are also located on the first side of the laser chip 900. Compared to the first differential drive signal line 4221 and the second differential drive signal line 4222, the third differential drive signal line 4223 and the fourth differential drive signal line 4224 have longer wiring lengths to rationally deploy the signal lines and avoid conflicts.

[0385] In some embodiments, the fifth differential drive signal line 4225 and the sixth differential drive signal line 4226 are located on the second side of the laser chip 900, and the seventh differential drive signal line 4227 and the eighth differential drive signal line 4228 are also located on the second side of the laser chip 900. Similarly, compared to the seventh differential drive signal line 4227 and the eighth differential drive signal line 4228, the fifth differential drive signal line 4225 and the sixth differential drive signal line 4226 have longer wiring lengths to rationally deploy the signal lines and avoid conflicts.

[0386] In some embodiments, a first bias electrode 918 and a second bias electrode 919 are formed on the surface of the laser chip 900. One end of the first bias electrode 918 is electrically connected to the circuit board 300, and the other end is electrically connected to the P-type electrode 916. One end of the second bias electrode 919 is electrically connected to the circuit board 300, and the other end is electrically connected to the N-type electrode 917, thereby inputting a bias current to the light-emitting region 910.

[0387] In some embodiments, the substrate 420 has a first bias pad 4271 and a second bias pad 4272 on its surface. One end of the first bias pad 4271 is electrically connected to the circuit board 300, and the other end is electrically connected to the first bias electrode 918 via wire bonding. One end of the second bias pad 4272 is electrically connected to the circuit board 300, and the other end is electrically connected to the second bias electrode 919 via wire bonding.

[0388] Figure 23 A surface structure of a laser component according to some embodiments Figure 2 .like Figure 23 As shown, in some embodiments, the surface of the substrate 420 is provided with differential drive signal lines corresponding to four electroabsorption modulation regions.

[0389] In some embodiments, taking the first electroabsorption modulation region 940 as an example, the first DC electrode 9473 and the first RF electrode 9471 are electrically connected through a first connecting resistor 9491. The first RF electrode 9471 is electrically connected to the first electrode portion 945, thereby realizing the electrical connection between the first DC electrode 9473 and the first electrode portion 945. The first connecting resistor 9491 can be an on-chip integrated resistor.

[0390] In some embodiments, the second DC electrode 9474 and the second RF electrode 9472 are electrically connected via a second connection resistor 9492. The second RF electrode 9472 is electrically connected to the second electrode portion 946, thereby realizing the electrical connection between the second DC electrode 9474 and the second electrode portion 946.

[0391] In some embodiments, a fifth signal pad 4241 and a sixth signal pad 4243 are formed on the surface of the substrate 420 adjacent to the laser chip 900. The fifth signal pad 4241 and the sixth signal pad 4243 are located on the sides of the first differential drive signal line 4221 and the second differential drive signal line 4222, respectively.

[0392] In some embodiments, a seventh signal pad 4242 and an eighth signal pad 4244 are formed on the surface of the substrate 420 adjacent to the circuit board 300.

[0393] In some embodiments, a first differential bias signal line 4251 is connected between the fifth signal pad 4241 and the seventh signal pad 4242. The fifth signal pad 4241 is used to electrically connect to the first DC electrode 9473, and the seventh signal pad 4242 is used to electrically connect to the circuit board 300. One end of the first differential bias signal line 4251 is electrically connected to the circuit board 300, and the other end is wire-connected to the first DC electrode 9473. The first DC electrode 9473 is electrically connected to the first electrode portion 945, thereby inputting a first differential reverse bias voltage to the first electroabsorption modulation region 940.

[0394] In some embodiments, a second differential bias signal line 4252 is connected between the sixth signal pad 4243 and the eighth signal pad 4244. The sixth signal pad 4243 is electrically connected to the second DC electrode 9474, and the eighth signal pad 4244 is electrically connected to the circuit board 300. One end of the second differential bias signal line 4252 is electrically connected to the circuit board 300, and the other end is wire-connected to the second DC electrode 9474. The second DC electrode 9474 is electrically connected to the second electrode portion 946, thereby inputting a second differential reverse bias voltage to the first electroabsorption modulation region 940.

[0395] In some embodiments, the first differential bias signal line 4251 and the second differential bias signal line 4252 are respectively located inside the substrate 420 to avoid crosstalk between the differential drive signal and the differential reverse bias electrode. At the same time, more space is reserved for the differential drive signal lines to be arranged on the surface of the substrate 420, so that the first differential drive signal lines and the second differential drive signal lines corresponding to multiple electroabsorption modulation regions are all distributed on the surface of the substrate 420, optimizing the spatial layout and ensuring signal transmission quality.

[0396] In some embodiments, the fifth signal pad 4241 has a metal via hole inside the substrate 420, and is then electrically connected to the seventh signal pad 4242 through internal traces in the substrate 420, thereby embedding the first differential bias signal line 4251 inside the substrate 420. In some embodiments, the sixth signal pad 4243 has a metal via hole inside the substrate 420, and is then electrically connected to the eighth signal pad 4244 through internal traces in the substrate 420, thereby embedding the second differential bias signal line 4252 inside the substrate 420.

[0397] In some embodiments, with reference to the first electroabsorption modulation region 940, a third differential bias signal line 4253 and a fourth differential bias signal line 4254 are formed inside the substrate 420 to input a differential reverse bias voltage to the second electroabsorption modulation region 950.

[0398] In some embodiments, with reference to the first electroabsorption modulation region 940, a fifth differential bias signal line 4255 and a sixth differential bias signal line 4256 are formed inside the substrate 420 to input a differential reverse bias voltage to the third electroabsorption modulation region 960.

[0399] In some embodiments, with reference to the first electroabsorption modulation region 940, a seventh differential bias signal line 4257 and an eighth differential bias signal line 4258 are formed inside the substrate 420 to input a differential reverse bias voltage to the fourth electroabsorption modulation region 970.

[0400] Figure 24 This is a schematic diagram of a capacitor arrangement according to some embodiments. Figure 25 This is a schematic diagram of a laser chip circuit according to some embodiments. Figure 24 and Figure 25 As shown, in some embodiments, an integrated capacitor design is used, which allows for the direct addition of a coupling capacitor at the output of the electroabsorption modulation region to achieve DC isolation and matched filtering.

[0401] In some embodiments, taking the first electroabsorption modulation region 940 as an example, the surface of the substrate 420 near the laser chip 900 is provided with a sixth signal pad 4243, a second signal pad 4232, a first signal pad 4231 and a fifth signal pad 4241, which are respectively electrically connected to the second DC electrode 9474, the second RF electrode 9472, the first RF electrode 9471 and the first DC electrode 9473.

[0402] In some embodiments, a coupling capacitor 426 is connected in series between the sixth signal pad 4243 and the fifth signal pad 4241 to achieve effective isolation between the DC positive and negative terminals. The coupling capacitor 426 has the characteristic of passing AC and blocking DC. The coupling capacitor 426 can achieve DC isolation and matched filtering.

[0403] In some embodiments, the coupling capacitor 426 is disposed in the inner layer of the substrate 420. The sixth signal pad 4243 and the fifth signal pad 4241 respectively drill metal vias into the inner layer of the substrate 420, thereby connecting the coupling capacitor 426 in series between them.

[0404] like Figure 25 As shown, in some embodiments, capacitor C4 in the circuit diagram is coupling capacitor 426. Black dot 1 in the circuit diagram represents the signal access point of the second DC electrode 9474, and black dot 4 represents the signal access point of the first DC electrode 9473. Black dot 2 represents the signal access point of the second RF electrode 9472, and black dot 3 represents the signal access point of the first RF electrode 9471.

[0405] In some embodiments, a first differential reverse bias voltage signal is applied at the signal access point of the first DC electrode 9473. This signal is split into components DC1+ and DC2+ at this access point. Component DC1+ flows into the first electrode section via wire L5 and resistor R6. Wire L5 is the connection between the fifth signal pad 4241 and the first DC electrode 9473, and resistor R6 is the first connection resistor 9491 between the first DC electrode 9473 and the first RF electrode 9471. Component DC2+ flows upward into the coupling capacitor 426, where it is open-circuited, thus achieving DC isolation.

[0406] In some embodiments, a second differential reverse bias voltage signal is applied at the signal access point of the second DC electrode 9474. This second differential reverse bias voltage signal is split into components DC1- and DC2- at this access point. Component DC1- flows into the second electrode section via wire L6 and resistor R7. Wire L6 is the connection between the sixth signal pad 4243 and the second DC electrode 9474, and resistor R7 is the second connection resistor 9492 between the second DC electrode 9474 and the second RF electrode 9472. Component DC2- flows downwards into the coupling capacitor 426, where it is open-circuited, thus achieving DC isolation.

[0407] In some embodiments, a second differential modulation drive signal is connected at the signal access point of the second radio frequency electrode 9472. The second differential modulation drive signal is split into components RF1- and RF2-. RF1- flows downward into the second electrode portion 946, and RF2- flows to the right into the coupling capacitor 426.

[0408] In some embodiments, a first differential drive modulation signal is introduced at the signal access point of the first RF electrode 9471. The first differential drive modulation signal is also split into components RF1+ and RF2+, where RF1+ flows upward into the first electrode portion 945, and RF2+ flows to the right into the coupling capacitor 426. The component RF2- of the second differential modulation drive signal and the component RF2+ of the first differential modulation drive signal merge within the coupling capacitor 426, canceling each other out, thereby achieving filtering and improving the chip's noise immunity.

[0409] In some embodiments, the laser chip 900 can be a single-channel laser chip or an array-emitting laser chip. The following embodiments use a single-channel laser chip 900 as an example for illustrative purposes.

[0410] Figure 26 This is a schematic diagram of the structure of a laser chip according to some embodiments. Figure 26 As shown, in some embodiments, the laser chip 900 can be an EML laser chip.

[0411] In some embodiments, the laser chip 900 may include a light-emitting region 910. The light-emitting region 910 is configured to emit light that does not carry a signal.

[0412] In some embodiments, the laser chip 900 may include an electro-absorption modulation region 920. The electro-absorption modulation region 920 is configured to modulate the light emitted from the light-emitting region 910 to generate an optical signal.

[0413] In some embodiments, the light-emitting region 910 and the electro-absorption modulation region 920 are arranged along the light field transmission direction.

[0414] Figure 27 A laser chip structure according to some embodiments Figure 1 .like Figure 27 As shown, in some embodiments, the laser chip 900 includes a substrate 930a. A light-emitting region 910 and an electro-absorption modulation region 920 are respectively disposed on the surface of the substrate 930a. The light-emitting region 910 and the electro-absorption modulation region 920 are laterally aligned. The electro-absorption modulation region 920 is located in the direction of the emitted light field of the light-emitting region 910.

[0415] In some embodiments, the light-emitting region 910 emits light without carrying a signal, and the electro-absorption modulation region 920 modulates the light emitted by the light-emitting region 910 to generate an optical signal, thereby the laser chip 900 outputs an optical signal.

[0416] In some embodiments, a bias current is provided to the light-emitting region 910, and the light-emitting region 910 emits light under the action of the bias current.

[0417] In some embodiments, the light-emitting region 910 may include a first N-InP layer 911a. The first N-InP layer 911a is located above the substrate 930a. The first N-InP layer 911a is an N-type doped InP layer. The first N-InP layer 911a primarily outputs N-type carriers.

[0418] In some embodiments, the light-emitting region 910 may include a first quantum well layer 912. The first quantum well layer 912 is located above the first N-InP layer 911a. The first quantum well layer 912 is the active region of the light-emitting region 910. The first quantum well layer 912 is configured to generate photons by recombination of P-type carriers and N-type carriers. The N-type carriers originate from the first N-InP layer 911a.

[0419] In some embodiments, the light-emitting region 910 may include a grating layer 913. The grating layer 913 is located above the first quantum well layer 912.

[0420] In some embodiments, the light-emitting region 910 may include a P-InP layer 940a. The P-InP layer 940a is located above the grating layer 913. The P-InP layer 940a is a P-type doped InP layer. The P-InP layer 940a primarily outputs P-type carriers. The P-InP layer 940a inputs P-type carriers to the first quantum well layer 912.

[0421] In some embodiments, within the first quantum well layer 912, stimulated emission causes discrete P-type and N-type carrier pairs to recombine and generate photons, thereby converting injected carriers into photons. These photons are reflected by the resonant cavity or distributed feedback grating to form positive feedback, generating laser light. By changing the current injected into the grating layer 913, the effective refractive index of the grating layer 913 can be altered, thereby changing the laser resonant lasing wavelength and achieving output at a specific wavelength. The light output from the first quantum well layer 912 does not carry a signal.

[0422] In some embodiments, the first N-InP layer 911a is larger in size to support the first quantum well layer 912, the grating layer 913 and the P-InP layer.

[0423] In some embodiments, a reverse bias voltage and a modulation current signal are provided to the electroabsorption modulation region 920. Under the action of the reverse bias voltage, the intensity of the light emitted by the light-emitting region 910 changes with the modulation current signal, thereby modulating the intensity and generating an optical signal carrying information.

[0424] In some embodiments, the electroabsorption modulation region 920 may include a second N-InP layer 921. The second N-InP layer 921 is located above the substrate 930a. The second N-InP layer 921 is an N-type doped InP layer. The second N-InP layer 921 primarily outputs N-type carriers.

[0425] In some embodiments, the electroabsorption modulation region 920 may include a second quantum well layer 922. The second quantum well layer 922 is located above the second N-InP layer 921. The second quantum well layer 922 is the active region of the electroabsorption modulation region 920.

[0426] In some embodiments, the electroabsorption modulation region 920 may include a P-InP layer 940a. The P-InP layer 940a is located above the second quantum well layer 922. The P-InP layer 940a is a P-type doped InP layer. The P-InP layer 940a primarily outputs P-type carriers. The P-InP layer 940a inputs P-type carriers to the second quantum well layer 922, and the second N-InP layer 921 inputs N-type carriers to the second quantum well layer 922, thereby inputting a signal to the electroabsorption modulation region 920.

[0427] In some embodiments, the light-emitting region 910 and the electro-absorption modulation region 920 share a P-InP layer 940a. That is, the P-InP layer 940a covers the corresponding regions of the light-emitting region 910 and the electro-absorption modulation region 920. The P-InP layer 940a extends from the corresponding region of the light-emitting region 910 to the corresponding region of the electro-absorption modulation region 920. The P-InP layer 940a extends from the surface of the grating layer 913 to the surface of the second quantum well layer 922. In some embodiments, the light-emitting region 910 and the electro-absorption modulation region 920 may not share the P-InP layer 940a; this is not a limitation.

[0428] In some embodiments, the second N-InP layer 921 is larger in size to support the second quantum well layer 922 and the P-InP layer 940a.

[0429] In some embodiments, the electroabsorption modulation region 920 may include a first electrode portion 923. Exemplarily, the first electrode portion 923 is a P-type electrode.

[0430] In some embodiments, the electroabsorption modulation region 920 may include a second electrode portion 924. Exemplarily, the second electrode portion 924 is an N-type electrode. The second electrode portion 924 and the first electrode portion 923 are coplanar electrodes, and both are located on the upper surface of the substrate 420.

[0431] In some embodiments, the first electrode portion 923 is located on the surface of the P-InP layer 940a corresponding to the electroabsorption modulation region 920, and the second electrode portion 924 is located on the surface of the second N-InP layer 921. The width of the second N-InP layer 921 is greater than the width of the second quantum well layer 922, or the width of the second N-InP layer 921 is greater than the width of the P-InP layer 940a, to provide space for the second electrode portion 924.

[0432] In some embodiments, a reverse bias voltage and a driving modulation signal are provided to the electroabsorption modulation region 920. When the electroabsorption modulation region 920 is in operation, the light entering the second quantum well layer 922 is modulated by the driving modulation signal based on the electro-optic modulation effect of the second quantum well layer 922, generating an optical signal carrying information.

[0433] In some embodiments, as the integration density of optical modules increases, it is necessary to further reduce the power consumption of the laser chip 900 to meet overall power consumption requirements. The laser chip 900 employs a differential drive mode to effectively reduce power consumption. The differential drive modulation signals enter the electroabsorption modulation region 920 respectively; these two differential signals have the same amplitude and frequency but opposite phase. Compared with single-ended drive chips, differential drive has advantages such as stronger noise immunity, longer transmission distance, and lower power consumption.

[0434] In some embodiments, when the light-emitting region 910 and the electro-absorption modulation region 920 share an N-InP layer, the driving modulation signal accessed from the N-InP layer to the electro-absorption modulation region will be interfered with by the light-emitting region 910, making differential driving difficult.

[0435] In some embodiments, the laser chip 900 may include an electrically isolated region 951. The electrically isolated region 951 is located between the first N-InP layer 911a and the second N-InP layer 921, and the electrically isolated region 951 provides N-plane electrical isolation between the light-emitting region 910 and the electro-absorption modulation region 920.

[0436] In some embodiments, the electrically isolated region 951 is a high-resistivity region, preventing charge carriers from entering the other party's working region through the electrically isolated region 951. This avoids interference from the light-emitting region 910 on the driving modulation signal accessed from the second N-InP layer 921, thus ensuring the quality of the modulation signal. At the same time, it also avoids interference from the electrically absorbed modulation region 920 on the bias current signal accessed from the first N-InP layer 911a, thus ensuring the light output quality of the light-emitting region 910.

[0437] In some embodiments, the electrical isolation region 951 can be achieved by means of ion implantation or diffusion, which transforms the N-type semiconductor region between the first N-InP layer 911a and the second N-InP layer 921 into a high-resistivity region, thereby achieving electrical isolation.

[0438] In some embodiments, the laser chip 900 may include a connecting waveguide region 952. The connecting waveguide region 952 is located between the first quantum well layer 912 and the second quantum well layer 922. The connecting waveguide region 952 connects the first quantum well layer 912 and the second quantum well layer 922. Light output from the first quantum well layer 912 is transmitted through the connecting waveguide region 952 to the second quantum well layer 922 for signal modulation.

[0439] In some embodiments, ion implantation is performed downwards at the interface between the first quantum well layer 912 and the second quantum well layer 922. The ion implantation region is bombarded by the ion beam, forming deep-level defects and reducing conductivity, thus forming an electrically isolated region 951. The electrically isolated region 951 is a high-resistivity region, preventing charge carriers from entering the other party's working region through the electrically isolated region 951, thereby avoiding interference from the other party.

[0440] In some embodiments, after obtaining the electrically isolated region 951, an electrically isolated region of a predetermined thickness is etched to form a connecting waveguide region 952 on the surface of the electrically isolated region. The connecting waveguide region 952 is located between the first quantum well layer 912 and the second quantum well layer 922, and the connecting waveguide region 952 establishes an optical connection between the first quantum well layer 912 and the second quantum well layer 922. Exemplarily, the etching predetermined thickness should ensure that the thickness of the connecting waveguide region 952 matches the thickness of the first quantum well layer 912 and the second quantum well layer 922.

[0441] Figure 28 A laser chip structure according to some embodiments Figure 2 .like Figure 28 As shown, in some embodiments, the laser chip 900 includes a substrate 930a. A light-emitting region 910 and an electro-absorption modulation region 920 are respectively disposed on the surface of the substrate 930a.

[0442] In some embodiments, the laser chip 900 employs a differential drive mode to effectively reduce power consumption.

[0443] In some embodiments, the electroabsorption modulation region 920 may include a first radio frequency electrode 925. The first radio frequency electrode 925 is electrically connected to the first electrode portion 923 to input a first differential drive modulation signal to the electroabsorption modulation region 920.

[0444] In some embodiments, the electroabsorption modulation region 920 may include a first DC electrode 926. The first DC electrode 926 is electrically connected to the first electrode portion 923 to input a first differential reverse bias voltage to the electroabsorption modulation region 920.

[0445] In some embodiments, the electroabsorption modulation region 920 may include a second radio frequency electrode 927. The first radio frequency electrode 925 and the second radio frequency electrode 927 constitute a differential drive electrode. The second radio frequency electrode 927 is electrically connected to the second electrode portion 924 to input a second differential drive modulation signal to the electroabsorption modulation region 920.

[0446] In some embodiments, the electroabsorption modulation region 920 may include a second DC electrode 928. The first DC electrode 926 and the second DC electrode 928 constitute a differential reverse bias electrode. The second DC electrode 928 is electrically connected to the second electrode portion 924 to input a second differential reverse bias voltage to the electroabsorption modulation region 920.

[0447] In some embodiments, the first radio frequency electrode 925 and the first DC electrode 926 are located on opposite sides of the second N-InP layer 921. The second radio frequency electrode 927 and the second DC electrode 928 are located on opposite sides of the first N-InP layer 911a.

[0448] In some embodiments, the first radio frequency electrode 925, the first DC electrode 926, the second radio frequency electrode 927, and the second DC electrode 928 are respectively insulated from the substrate 930a.

[0449] In some embodiments, a first support portion 931, a second support portion 932, a third support portion 933, and a fourth support portion 934 are formed on the surface of the substrate 930a. The first support portion 931, the second support portion 932, the third support portion 933, and the fourth support portion 934 can each be a mesa structure composed of SiO2 and have a certain thickness.

[0450] In some embodiments, the first support portion 931 and the second support portion 932 are located on both sides of the first N-InP layer 911a. The third support portion 933 and the fourth support portion 934 are located on both sides of the second N-InP layer 921.

[0451] In some embodiments, a first radio frequency electrode 925 is supported on the surface of the first support portion 931. The first radio frequency electrode 925 may be a circular electrode, supported by the first support portion 931 to achieve an insulated connection with the substrate 930a. The first support portion 931 can achieve insulation between the first radio frequency electrode 925 and the substrate 930a.

[0452] In some embodiments, a first DC electrode 926 is supported on the surface of the second support portion 932. The first DC electrode 926 may be a circular electrode, supported by the second support portion 932 to achieve an insulated connection with the substrate 930a. The second support portion 932 can achieve insulation between the first DC electrode 926 and the substrate 930a.

[0453] In some embodiments, a second radio frequency electrode 927 is supported on the surface of the third support portion 933. The second radio frequency electrode 927 may be a circular electrode, supported by the third support portion 933 to achieve an insulated connection with the substrate 930a. The third support portion 933 can achieve insulation between the second radio frequency electrode 927 and the substrate 930a.

[0454] In some embodiments, a second DC electrode 928 is supported on the surface of the fourth support portion 934. The second DC electrode 928 may be a circular electrode, supported by the fourth support portion 934 to achieve an insulated connection with the substrate 930a. The fourth support portion 934 can achieve insulation between the second DC electrode 928 and the substrate 930a.

[0455] In some embodiments, the first support portion 931 and the second support portion 932 are respectively located on both sides of the second N-InP layer 921. The third support portion 933 and the fourth support portion 934 are respectively located on both sides of the first N-InP layer 911a.

[0456] In some embodiments, the first radio frequency electrode 925 is electrically connected to the first electrode portion 923 to input a first differential drive modulation signal to the electroabsorption modulation region 920; the second radio frequency electrode 927 is electrically connected to the second electrode portion 924 to input a second differential drive modulation signal to the electroabsorption modulation region 920. The first differential drive modulation signal and the second differential drive modulation signal have the same amplitude and frequency, but opposite phase.

[0457] In some embodiments, the first DC electrode 926 is electrically connected to the first electrode portion 923 to input a first differential reverse bias voltage to the electroabsorption modulation region 920; the second DC electrode 928 is electrically connected to the second electrode portion 924 to input a second differential reverse bias voltage to the electroabsorption modulation region 920. Similarly, the first differential reverse bias voltage and the second differential reverse bias voltage have the same amplitude and frequency, but opposite phase.

[0458] In some embodiments, when the electroabsorption modulation region 920 is operational, the first electrode portion 923 and the second electrode portion 924 are simultaneously applied with a first differential driving modulation signal and a second differential driving modulation signal with opposite phases, forming a differential driving mode. Through the electro-optic modulation effect of the second quantum well layer 922, the light entering the second quantum well layer 922 is modulated by the differential driving modulation signal, generating an optical signal carrying information. Using a coplanar electrode differential driving method for signal modulation reduces power consumption.

[0459] In some embodiments, the substrate 420 carries the laser chip 900. The surface of the substrate 420 is covered with circuit patterns to establish electrical connections with the circuit board 300 and the laser chip 900, respectively, thereby transmitting signals to the laser chip 900.

[0460] In some embodiments, a bias current source is provided on the surface of the circuit board 300. The bias current source is electrically connected to the substrate 420, which is in turn electrically connected to the laser chip 900, thereby inputting the bias current into the light-emitting area 910 of the laser chip 900, so that the light-emitting area 910 emits light.

[0461] In some embodiments, a bias circuit is provided on the surface of the circuit board 300. The bias circuit has a first differential output terminal and a second differential output terminal. The first differential output terminal of the bias circuit is electrically connected to the substrate 420, and the first DC electrode 926 is electrically connected to the substrate 420. Thus, the first differential output terminal of the bias circuit is electrically connected to the first DC electrode 926, thereby transmitting the first differential reverse bias voltage output by the bias circuit to the first DC electrode 926. Then, it is input to the electroabsorption modulation region 920 via the first electrode portion 923.

[0462] In some embodiments, the second differential output terminal of the bias circuit is electrically connected to the substrate 420, and the second DC electrode 928 is electrically connected to the substrate 420. The second differential output terminal of the bias circuit is then electrically connected to the second DC electrode 928, thereby transmitting the second differential reverse bias voltage output by the bias circuit to the second DC electrode 928. It is then input to the electroabsorption modulation region 920 via the second electrode portion 924.

[0463] In some embodiments, a driver chip is provided on the surface of the circuit board 300. The driver chip has a first differential output terminal and a second differential output terminal. The first differential output terminal of the driver chip is electrically connected to the substrate 420, and the first radio frequency electrode 925 is electrically connected to the substrate 420. Thus, the first differential output terminal of the driver chip is electrically connected to the first radio frequency electrode 925, thereby transmitting the first differential drive modulation signal output by the driver chip to the first radio frequency electrode 925. Then, it is input to the electroabsorption modulation region 920 via the first electrode portion 923.

[0464] In some embodiments, the second differential output terminal of the driver chip is electrically connected to the substrate 420, and the second radio frequency electrode 962 is electrically connected to the substrate 420. The second differential output terminal of the driver chip is then electrically connected to the second radio frequency electrode 962, thereby transmitting the second differential drive modulation signal output by the driver chip to the second radio frequency electrode 962. The signal is then input to the electroabsorption modulation region 920 via the second electrode portion 924.

[0465] Figure 29 A laser chip structure according to some embodiments Figure 3 .like Figure 29 As shown, in some embodiments, the laser chip 900 includes a substrate 930a. A light-emitting region 910 and an electro-absorption modulation region 920 are respectively disposed on the surface of the substrate 930a.

[0466] In some embodiments, the first radio frequency electrode 925 and the first DC electrode 926 are electrically connected to the first electrode portion 923, so as to transmit the first differential drive modulation signal and the first reverse bias voltage signal to the electroabsorption modulation region 920 via the first electrode portion 923, respectively.

[0467] In some embodiments, the second radio frequency electrode 927 and the second DC electrode 928 are electrically connected to the second electrode portion 924, so as to transmit the second differential drive modulation signal and the second reverse bias voltage signal to the electroabsorption modulation region 920 via the second electrode portion 924, respectively.

[0468] In some embodiments, the first electrode portion 923 and the second electrode portion 924 are coplanar electrodes, both of which are disposed facing the upper surface of the substrate 420.

[0469] In some embodiments, the first radio frequency electrode 925, the first DC electrode 926, the second radio frequency electrode 927, and the second DC electrode 928 are respectively disposed facing the upper surface of the substrate 420.

[0470] In some embodiments, the first support portion 931 and the second support portion 932 are respectively located on both sides of the second N-InP layer 921. The third support portion 933 and the fourth support portion 934 are respectively located on both sides of the first N-InP layer 911a. Then, the first radio frequency electrode 925 and the first DC electrode 926 are respectively located on both sides of the second N-InP layer 921, and the second radio frequency electrode 927 and the second DC electrode 928 are respectively located on both sides of the first N-InP layer 911a.

[0471] In some embodiments, the first electrode portion 923 is located above the second N-InP layer 921, and the first radio frequency electrode 925 and the first DC electrode 926 are located on both sides of the first electrode portion 923.

[0472] In some embodiments, the first support portion 931 and the third support portion 933 are located on one side of the P-InP layer 940a, and the first radio frequency electrode 925 and the second radio frequency electrode 927 are respectively located on one side of the P-InP layer 940a, so that the differential modulation drive signal can be accessed from the substrate 420 carrying the laser chip at the same distance, thereby reducing parasitic inductance and capacitance.

[0473] In some embodiments, the second support portion 932 and the fourth support portion 934 are located on the other side of the P-InP layer 940a. Therefore, the first DC electrode 926 and the second DC electrode 928 are located on the other side of the P-InP layer 940a, away from the first RF electrode 925 and the second RF electrode 927, thereby reducing parasitic capacitance. Simultaneously, the DC signal on the substrate 420 carrying the laser chip can be accessed from the other side of the laser chip via the first DC electrode 926 and the second DC electrode 928, without needing to share the first RF electrode 925 or the second RF electrode 927, reducing wire bonding difficulty and providing flexibility in the arrangement of the substrate 420.

[0474] In some embodiments, the second radio frequency electrode 927 and the second electrode portion 924 are located on opposite sides of the P-InP layer 940a, and the second DC electrode 928 and the second electrode portion 924 are located on the same side of the P-InP layer 940a.

[0475] In some embodiments, the second electrode portion 924 is located on the surface of the second N-InP layer 921, and the second radio frequency electrode 927 and the second DC electrode 928 are located on opposite sides of the first N-InP layer 911a. In this case, the second radio frequency electrode 927 is located on the diagonal side of the second electrode portion 924, and the second DC electrode 928 is located on the straight side of the second electrode portion 924.

[0476] In some embodiments, the first radio frequency electrode 925 and the first DC electrode 926 are electrically connected to the first electrode portion 923, respectively. Since the first radio frequency electrode 925 and the first DC electrode 926 are located on opposite sides of the first electrode portion 923, a first electrical connection bridge 971 can be connected between the first radio frequency electrode 925 and the first DC electrode 926. One end of the first electrical connection bridge 971 is electrically connected to the first radio frequency electrode 925, and the other end is electrically connected to the first DC electrode 926. The first electrical connection bridge 971 is also electrically connected to the first electrode portion 923, so that the first radio frequency electrode 925 and the first DC electrode 926 are respectively electrically connected to the first electrode portion 923. The first support portion 931 and the second support portion 932 act as bridge piers, providing support for the first electrical connection bridge 971.

[0477] In some embodiments, the second radio frequency electrode 927 and the second DC electrode 928 are electrically connected to the second electrode portion 924, respectively. Since the second radio frequency electrode 927 and the second electrode portion 924 are located on opposite sides of the P-InP layer 940a, and the second DC electrode 928 and the second electrode portion 924 are located on the same side of the P-InP layer 940a, the electrical connection between the second radio frequency electrode 927 and the second electrode portion 924 requires a transfer. Therefore, a transfer electrode portion 9341 is provided on the surface of the fourth support portion 934, and the transfer electrode portion 9341 is electrically connected to the second DC electrode 928 located on the fourth support portion 934.

[0478] In some embodiments, a second electrical connection bridge 972 connects the second electrode portion 924 and the transition electrode portion 9341, and the transition electrode portion 9341 is electrically connected to the second DC electrode 928, thereby establishing an electrical connection between the second DC electrode 928 and the second electrode portion 924, realizing the electrical connection between the two. The second N-InP layer 921 and the fourth support portion 934 act as piers, providing support for the second electrical connection bridge 972.

[0479] In some embodiments, a second electrical connection bridge 972 connects the second electrode portion 924 and the transition electrode portion 9341, and a third electrical connection bridge 973 connects the transition electrode portion 9341 and the second radio frequency electrode 927, thereby establishing an electrical connection between the second radio frequency electrode 927 and the second electrode portion 924, realizing their electrical connection. The third support portion 933 and the fourth support portion 934 act as bridge piers, providing support for the third electrical connection bridge 973.

[0480] In some embodiments, the first electrical connection bridge 971 spans the electroabsorption modulation region 920 and has a relatively long length. A P-type ohmic contact layer 929 is provided between the first electrode portion 923 and the P-InP layer to support the first electrical connection bridge 971 and reduce the risk of collapse caused by the long length of the first electrical connection bridge 971.

[0481] In some embodiments, the third electrical connection bridge 973 spans the light-emitting area 920 and is also relatively long. The third electrical connection bridge 973 rests above the waveguide of the light-emitting area 920 and is isolated and supported by the thick dielectric support portion 974, thereby reducing the risk of collapse caused by the excessive length of the third electrical connection bridge 973.

[0482] In some embodiments, the first electrical connection bridge 971, the second electrical connection bridge 972, and the third electrical connection bridge 973 may each be an air bridge. Air bridges utilize air, which has a low dielectric constant, as the dielectric, reducing parasitic capacitance. Due to the low dielectric constant of air, signal transmission speed in air bridges is relatively fast, and losses are low. The structural design of air bridges can optimize the signal transmission path, reduce signal reflection and scattering during transmission, thereby improving signal transmission efficiency and quality.

[0483] In some embodiments, the impedance of the electro-absorption modulation region 920 is greater than the impedance of the differential signal transmission line on the surface of the substrate 420. To achieve impedance matching between the electro-absorption modulation region 920 and the differential signal transmission line, a matching resistor is connected in parallel with the electro-absorption modulation region 920 to reduce its impedance, thereby achieving impedance matching. Exemplarily, the matching resistor has a preset impedance, such as 50 ohms.

[0484] In some embodiments, a matching resistor may be disposed on the surface of substrate 420 and connected in parallel with electroabsorption modulation region 920.

[0485] In some embodiments, the matching resistor can be integrated on the surface of the laser chip 900. A first matching resistor 981a and a second matching resistor 982a are formed on the surfaces of the second support portion 932 and the fourth support portion 934, respectively, to achieve on-chip integration of the matching resistor, eliminating the need to set the matching resistor on the surface of the substrate 420, thereby reducing the substrate size.

[0486] In some embodiments, the first matching resistor 981a is connected in parallel with the electroabsorption modulation region 920, and the second matching resistor 982a is connected in parallel with the electroabsorption modulation region 920 to reduce the impedance of the electroabsorption modulation region 920 and achieve impedance matching between the electroabsorption modulation region 920 and the differential signal transmission line on the surface of the substrate 420.

[0487] Based on the laser chip provided in the above embodiments, this disclosure provides a method for fabricating a laser chip. Figure 30 This is a schematic diagram of a laser chip fabrication method according to some embodiments. Figure 30 As shown. This disclosure provides a method for fabricating a laser chip, including:

[0488] S100: An N-InP layer is grown along the surface of the substrate, and a first quantum well layer and a second quantum well layer are grown together along the surface of the N-InP layer. A grating layer is formed on the surface of the first quantum well layer.

[0489] In some embodiments, an N-InP layer is grown along the substrate surface, and a first quantum well layer 912 and a second quantum well layer 922 are grown together along the surface of the N-InP layer. A grating layer 913 is formed on the surface of the first quantum well layer 912. The first quantum well layer 912 and the second quantum well layer 922 are the active regions of the light-emitting region 910 and the electro-absorption modulation region 920, respectively. Light emission from the light-emitting region 910 occurs within the first quantum well layer 912, and signal modulation from the electro-absorption modulation region 920 occurs within the second quantum well layer 922.

[0490] In some embodiments, when the light-emitting region 910 and the electro-absorption modulation region 920 share the same N-InP layer, the drive modulation signal that enters the electro-absorption modulation region from the N-InP layer will be interfered with by the light-emitting region 9410, making differential driving difficult.

[0491] In some embodiments, the laser chip 900 may include an electrically isolated region 951. The electrically isolated region 951 is located between the first N-InP layer 911a and the second N-InP layer 921, and the electrically isolated region 951 provides N-plane electrical isolation between the light-emitting region 910 and the electro-absorption modulation region 920.

[0492] In some embodiments, the electrical isolation region 951 can be achieved by means of ion implantation or diffusion, which transforms the N-type semiconductor region between the first N-InP layer 911a and the second N-InP layer 921 into a high-resistivity region, thereby achieving electrical isolation.

[0493] In some embodiments, the laser chip 900 may include a connecting waveguide region 952. The connecting waveguide region 952 is located between the first quantum well layer 912 and the second quantum well layer 922. The connecting waveguide region 952 connects the first quantum well layer 912 and the second quantum well layer 922. Light output from the first quantum well layer 912 is transmitted through the connecting waveguide region 952 to the second quantum well layer 922 for signal modulation.

[0494] In some embodiments, ion implantation is performed downwards at the interface between the first quantum well layer 912 and the second quantum well layer 922. The ion implantation region is bombarded by the ion beam, forming deep-level defects and reducing conductivity, thus forming an electrically isolated region 951. The electrically isolated region 951 is a high-resistivity region, preventing charge carriers from entering the other party's working region through the electrically isolated region 951, thereby avoiding interference from the other party.

[0495] In some embodiments, after obtaining the electrically isolated region 951, an electrically isolated region of a predetermined thickness is etched to form a connecting waveguide region 952 on the surface of the electrically isolated region. The connecting waveguide region 952 is located between the first quantum well layer 912 and the second quantum well layer 922, and the connecting waveguide region 952 establishes an optical connection between the first quantum well layer 912 and the second quantum well layer 922. Exemplarily, the etching predetermined thickness should ensure that the thickness of the connecting waveguide region 952 matches the thickness of the first quantum well layer 912 and the second quantum well layer 922.

[0496] S200: A P-InP layer is grown along the surface of the grating layer and the second quantum well layer.

[0497] In some embodiments, a P-InP layer 940a is grown along the surface of the grating layer 913 and the second quantum well layer 922. The P-InP layer 940a may cover the corresponding regions of the light-emitting region 910 and the electro-absorption modulation region 920.

[0498] S300: A first support portion, a second support portion, a third support portion and a fourth support portion are deposited on the substrate surface respectively. The first support portion and the third support portion are located on one side of the P-InP layer, and the second support portion and the fourth support portion are located on the other side of the P-InP layer.

[0499] In some embodiments, the electroabsorption modulation region 920 may include a first radio frequency electrode 925, a first DC electrode 926, a second radio frequency electrode 927, and a second DC electrode 928 for differential driving.

[0500] In some embodiments, a first support portion 931, a second support portion 932, a third support portion 933 and a fourth support portion 934 are deposited on the surface of the substrate 930a to support the first radio frequency electrode 925, the first DC electrode 926, the second radio frequency electrode 927 and the second DC electrode 928, respectively.

[0501] S400: A first radio frequency electrode is deposited on the surface of the first support portion, and a second radio frequency electrode is deposited on the surface of the third support portion; a first DC electrode is deposited on the surface of the second support portion, and a second DC electrode is deposited on the surface of the fourth support portion.

[0502] In some embodiments, a first radio frequency electrode 925 is deposited on the surface of the first support portion 931, a second radio frequency electrode 927 is deposited on the surface of the third support portion 933, a first DC electrode 926 is deposited on the surface of the second support portion 932, and a second DC electrode 928 is deposited on the surface of the fourth support portion 934.

[0503] S500: The second electrode portion is formed by deposition on the surface of the N-InP layer, and the transition electrode portion is formed by deposition on the surface of the fourth support portion.

[0504] In some embodiments, a second electrode portion 924 is deposited on the surface of the N-InP layer. A transition electrode portion 9341 is formed on the surface of the fourth support portion 934.

[0505] In some embodiments, the second electrode portion 924 is located on the surface of the second N-InP layer 921.

[0506] S600: A first electrical connection bridge is formed between the first radio frequency electrode and the first DC electrode, a second electrical connection bridge is formed between the second electrode portion and the transfer electrode portion, and a third electrical connection bridge is formed between the transfer electrode portion and the second radio frequency electrode.

[0507] S700: The first electrode portion is grown along the surface of the first electrical connection bridge.

[0508] In some embodiments, the first radio frequency electrode 925 and the first DC electrode 926 are electrically connected to the first electrode portion 923, respectively. Since the first radio frequency electrode 925 and the first DC electrode 926 are located on opposite sides of the first electrode portion 923, a first electrical connection bridge 971 can be connected between the first radio frequency electrode 925 and the second radio frequency electrode 927. One end of the first electrical connection bridge 971 is electrically connected to the first radio frequency electrode 925, and the other end is electrically connected to the second radio frequency electrode 927. The first electrical connection bridge 971 is also electrically connected to the first electrode portion 923, so that the first radio frequency electrode 925 and the first DC electrode 926 are respectively electrically connected to the first electrode portion 923.

[0509] In some embodiments, the second radio frequency electrode 927 and the second DC electrode 928 are electrically connected to the second electrode portion 924, respectively. Since the second radio frequency electrode 927 and the second electrode portion 924 are located on opposite sides of the P-InP layer 940a, and the second DC electrode 928 and the second electrode portion 924 are located on the same side of the P-InP layer 940a, the electrical connection between the second radio frequency electrode 927 and the second electrode portion 924 requires a transfer. Therefore, a transfer electrode portion 9341 is provided on the surface of the fourth support portion 934, and the transfer electrode portion 9341 is electrically connected to the second DC electrode 928 located on the fourth support portion 934.

[0510] In some embodiments, a second electrical connection bridge 972 is connected between the second electrode portion 924 and the transfer electrode portion 9341, and the transfer electrode portion 9341 is electrically connected to the second DC electrode 928, thereby establishing an electrical connection between the second DC electrode 928 and the second electrode portion 924, and realizing the electrical connection between the two.

[0511] In some embodiments, a second electrical connection bridge 972 is connected between the second electrode portion 924 and the transition electrode portion 9341, and a third electrical connection bridge 973 is connected between the transition electrode portion 9341 and the second radio frequency electrode 927, thereby establishing an electrical connection between the second radio frequency electrode 927 and the second electrode portion 924, and realizing the electrical connection between the two.

[0512] In some embodiments, the first electrical connection bridge 971, the second electrical connection bridge 972, and the third electrical connection bridge 973 may each be an air bridge. Air bridges utilize air, which has a low dielectric constant, as the dielectric, reducing parasitic capacitance. Due to the low dielectric constant of air, signal transmission speed in air bridges is relatively fast, and losses are low. The structural design of air bridges can optimize the signal transmission path, reduce signal reflection and scattering during transmission, thereby improving signal transmission efficiency and quality.

[0513] Figure 31 This is a schematic diagram illustrating the fabrication process of a first electrical connection bridge according to some embodiments. For example... Figure 31As shown, in some embodiments, the fabrication of the first electrical connection bridge is used as an example to illustrate the fabrication of the electrical connection bridge.

[0514] In some embodiments, the fabrication process may include: coating a photoresist along the region between the P-InP layer and the substrate. This step corresponds to... Figure 12 Step S181 in the example. Photoresist is coated along the P-InP layer toward the substrate regions corresponding to the first support 931 and the second support 932.

[0515] In some embodiments, the fabrication process may include: forming the arched bridge surface region by photolithography. This step corresponds to... Figure 12 Steps S182 and S183 in the text.

[0516] In some embodiments, the fabrication process may include: curing the shape of the photoresist into an arc-shaped arch structure by high-temperature baking. This step corresponds to... Figure 12 Step S184 in the text.

[0517] In some embodiments, photoresist is coated along the region between the P-InP layer and the substrate 930a. An arched bridge region is formed by photolithography. The shape of the photoresist is fixed into an arc-shaped arch structure by high-temperature baking. High-temperature curing alters the adhesive state of the photoresist, making it less susceptible to corrosion by the developer or stripper, and unaffected by subsequent metal lithography.

[0518] In some embodiments, the fabrication process may include: forming a first radio frequency electrode, a first direct current electrode, and a metal layer between the first radio frequency electrode and the first direct current electrode along the surface of a photoresist by metal photolithography and metal deposition, wherein the metal layer connects the first radio frequency electrode and the first direct current electrode. This step corresponds to... Figure 12 Step S185 in the middle.

[0519] In some embodiments, the fabrication process may include: peeling off the photoresist between the metal layer and the substrate to form an air gap between the metal layer and the substrate, thereby forming a first electrical connection bridge between the first radio frequency electrode and the first DC electrode. This step corresponds to... Figure 12 Step S186 in the text.

[0520] In some embodiments, a first radio frequency electrode 925, a first direct current electrode 926, and a metal layer between the first radio frequency electrode 925 and the first direct current electrode 926 are formed along the surface of a photoresist by metal photolithography and metal deposition, wherein the metal layer connects the first radio frequency electrode 925 and the first direct current electrode 926. When the photoresist between the metal layer and the substrate is peeled off, an air gap is formed between the metal layer and the substrate, the metal layer is suspended, and its morphology before photoresist removal is maintained, thereby forming a first electrical connection bridge 971 between the first radio frequency electrode 925 and the first direct current electrode 926.

[0521] Figure 32 This is a schematic diagram of a laser chip fabrication process according to some embodiments. Figure 1 , Figure 33 This is a schematic diagram of a laser chip fabrication process according to some embodiments. Figure 2 , Figure 34 This is a schematic diagram of a laser chip fabrication process according to some embodiments. Figure 3 .like Figures 32-34 As shown in the figures, in some embodiments, the fabrication process of the laser chip is illustrated, and the fabrication process of the laser chip includes:

[0522] In some embodiments, an N-InP layer is grown along the substrate surface, and a first quantum well layer 912 and a second quantum well layer 922 are grown together along the surface of the N-InP layer. A grating layer 913 is formed on the surface of the first quantum well layer 912. The first quantum well layer 912 and the second quantum well layer 922 are the active regions of the light-emitting region 910 and the electro-absorption modulation region 920, respectively. Light emission from the light-emitting region 910 occurs within the first quantum well layer 912, and signal modulation from the electro-absorption modulation region 920 occurs within the second quantum well layer 922. This process corresponds to step S110 shown in the accompanying drawings.

[0523] In some embodiments, when the light-emitting region 910 and the electro-absorption modulation region 920 share an N-InP layer, the driving modulation signal accessing the electro-absorption modulation region from the N-InP layer will be interfered with by the light-emitting region 9410, making differential driving difficult. Therefore, an electrical isolation region 951 is located between the first N-InP layer 911a and the second N-InP layer 921, providing N-plane electrical isolation between the light-emitting region 910 and the electro-absorption modulation region 920. In some embodiments, ion implantation is performed downwards at the interface between the first quantum well layer 912 and the second quantum well layer 922. The ion implantation region is bombarded by the ion beam, forming deep-level defects and reducing conductivity, thus forming the electrical isolation region 951. The electrical isolation region 951 is a high-resistivity region, preventing charge carriers from entering the other's working region, thereby avoiding interference from the other. This process corresponds to step S120 shown in the accompanying drawings.

[0524] In some embodiments, after obtaining the electrically isolated region 951, an electrically isolated region of a predetermined thickness is etched to form a connecting waveguide region 952 on the surface of the electrically isolated region. The connecting waveguide region 952 is located between the first quantum well layer 912 and the second quantum well layer 922, and the connecting waveguide region 952 establishes an optical connection between the first quantum well layer 912 and the second quantum well layer 922. This process corresponds to steps S130 and S140 shown in the accompanying drawings.

[0525] In some embodiments, a P-InP layer 940a is grown on the current surface. The P-InP layer 940a is laid across the entire plane. This process corresponds to step S150 shown in the accompanying drawings.

[0526] In some embodiments, etching is performed on the current structure to form an attachment. Figure 27 The structure shown is used to proceed with subsequent steps. This process corresponds to step S160 shown in the attached figure.

[0527] In some embodiments, a first support portion 931, a second support portion 932, a third support portion 933, and a fourth support portion 934 are formed on the surface of the substrate 930a. A first radio frequency electrode 925, a first direct current electrode 926, a second radio frequency electrode 927, and a second direct current electrode 928 are deposited on the surfaces of the first support portion 931, the second support portion 932, the third support portion 933, and the fourth support portion 934, respectively. This process corresponds to step S170 shown in the accompanying drawings.

[0528] In some embodiments, a first electrical connection bridge 971 is formed between the first radio frequency electrode 925 and the first DC electrode 926, a second electrical connection bridge 972 is formed between the second electrode portion 924 and the transition electrode portion 9341, and a third electrical connection bridge 973 is formed between the transition electrode portion 9341 and the second radio frequency electrode 927. The first electrode portion 923 is grown along the surface of the first electrical connection bridge 971. This process corresponds to step S180.

[0529] In this disclosure, by reasonably setting the first radio frequency electrode, the second radio frequency electrode, the first DC electrode, and the second DC electrode, signal modulation is achieved by coplanar electrode differential driving mode, thereby reducing power consumption.

[0530] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A first coupler, characterized by, The application relates to a semiconductor waveguide, which comprises the following parts: a substrate; an N-InP layer above the substrate; a P-InP layer above the N-InP layer; a waveguide layer, which comprises a nonlinear gradient section, a first non-gradient section and a second non-gradient section, one end of the nonlinear gradient section being connected to the first non-gradient section, the other end of the nonlinear gradient section being connected to the second non-gradient section; the outer contour line of the nonlinear gradient section comprises a first arc line and a second arc line, the first arc line being concave to the waveguide center, the second arc line being convex to the waveguide center, and the waveguide width between the first arc line and the second arc line gradually decreases in the direction from the first non-gradient section to the second non-gradient section; a doped layer in the N-InP layer, the refractive index of the doped layer being greater than the refractive index of the P-InP layer.

2. The first coupler of claim 1, wherein, The refractive index of the doped layer is greater than the refractive index of the P-InP layer, and the refractive index of the doped layer is less than the refractive index of the waveguide layer.

3. The first coupler of claim 1, wherein, The waveguide width of the first non-gradient section is greater than the waveguide width of the second non-gradient section.

4. The first coupler of claim 1, wherein, The waveguide layer is buried in the P-InP layer.

5. A laser chip, characterized by The application relates to a semiconductor waveguide, which comprises the following parts: a light emitting area, which comprises a first end and a second end, the first end emitting a first light beam, and the second end emitting a second light beam, the first light beam and the second light beam not carrying information; a first beam splitter, which is located on the transmission path of the first light beam, and is used for splitting the first light beam into a first split light and a second split light; the first split light and the second split light are transmitted along one side of the light emitting area; a second beam splitter, which is located on the transmission path of the second light beam, and is used for splitting the second light beam into a third split light and a fourth split light; the third split light and the fourth split light are transmitted along the other side of the light emitting area; a first electro-absorption modulation area, which is located on the transmission path of the first split light, and is configured to perform signal modulation on the first split light to generate a first optical signal; a second electro-absorption modulation area, which is located on the transmission path of the second split light, and is configured to perform signal modulation on the second split light to generate a second optical signal; the second electro-absorption modulation area and the first electro-absorption modulation area are located on one side of the light emitting area respectively; a third electro-absorption modulation area, which is located on the transmission path of the third split light, and is configured to perform signal modulation on the third split light to generate a third optical signal; a fourth electro-absorption modulation area, which is located on the transmission path of the fourth split light, and is configured to perform signal modulation on the fourth split light to generate a fourth optical signal; the fourth electro-absorption modulation area and the third electro-absorption modulation area are located on the other side of the light emitting area respectively; a first coupler, which is located on the light output path of the first electro-absorption modulation area, and is used for mode spot conversion of the first optical signal; a second coupler, which is located on the light output path of the second electro-absorption modulation area, and is used for mode spot conversion of the second optical signal; a third coupler, which is located on the light output path of the third electro-absorption modulation area, and is used for mode spot conversion of the third optical signal; a fourth coupler, which is located on the light output path of the fourth electro-absorption modulation area, and is used for mode spot conversion of the fourth optical signal.

6. The laser chip of claim 5, wherein, The first coupler comprises the following parts: a substrate; an N-InP layer above the substrate; A P-InP layer is located above the N-InP layer. A waveguide layer includes a nonlinear gradual section, a first non-gradual section, and a second non-gradual section. The nonlinear gradual section is connected to the first non-gradual section at one end and connected to the second non-gradual section at the other end. The first non-gradual section is directed towards the first EA modulation region. A doped layer is located in the N-InP layer. The refractive index of the doped layer is greater than the refractive index of the P-InP layer.

7. The laser chip of claim 5, wherein, The laser chip includes: A first transmission waveguide is connected to the first end of the light emitting region and the first optical splitter to input a first light beam into the first optical splitter. A second transmission waveguide is connected to the second end of the light emitting region and the second optical splitter to input a second light beam into the second optical splitter. The second transmission waveguide includes: A first bending region bends from the second end of the light emitting region towards the first end to change the transmission direction of the second light beam to the first end of the light emitting region, so that the first optical splitter and the second optical splitter are located on the same side of the light emitting region.

8. The laser chip of claim 5, wherein, The laser chip includes: A third transmission waveguide is connected to the first light output end of the first optical splitter and the first EA modulation region to transmit a first split light into the first EA modulation region. The third transmission waveguide includes a second bending region. A fourth transmission waveguide is connected to the second light output end of the first optical splitter and the second EA modulation region to transmit a second split light into the second EA modulation region. The fourth transmission waveguide includes a third bending region. The third bending region and the second bending region are bent towards one side of the light emitting region to guide the second split light and the first split light to the one side of the light emitting region, respectively. A fifth transmission waveguide is connected to the first light output end of the second optical splitter and the third EA modulation region to transmit a third split light into the third EA modulation region. The fifth transmission waveguide includes a fourth bending region. A sixth transmission waveguide is connected to the second light output end of the second optical splitter and the fourth EA modulation region to transmit a fourth split light into the fourth EA modulation region. The sixth transmission waveguide includes a fifth bending region. The fifth bending region and the fourth bending region are bent towards the other side of the light emitting region to guide the fourth split light and the third split light to the other side of the light emitting region, respectively.

9. The laser chip of claim 5, wherein, The first EA modulation region and the second EA modulation region are located on one side of the light emitting region. The third EA modulation region and the fourth EA modulation region are located on the other side of the light emitting region. The first EA modulation region includes: A substrate; An N-InP layer is located above the substrate; A second active layer is located above the N-InP layer; A P-InP layer is located above the second active layer; A first electrode part; A second electrode part; A first RF electrode is connected to the first electrode part by a first electrical connection bridge to electrically connect the first RF electrode and the first electrode part to input a first differential drive modulation signal to the first EA modulation region. The second radio frequency electrode is connected with the second electrode part through a second electric connection bridge to electrically connect the second radio frequency electrode with the second electrode part to input a second differential driving modulation signal to the first electric absorption modulation area; The first direct current electrode is connected with the first radio frequency electrode through a first connection resistance and a third electric connection bridge to electrically connect the first direct current electrode with the first radio frequency electrode, and further electrically connect the first direct current electrode with the first electrode part to input a first differential reverse bias voltage to the first electric absorption modulation area; The second direct current electrode is connected with the second radio frequency electrode through a second connection resistance and a fourth electric connection bridge to electrically connect the second direct current electrode with the second radio frequency electrode, and further electrically connect the second direct current electrode with the second electrode part to input a second differential reverse bias voltage to the first electric absorption modulation area.

10. The laser chip of claim 9, wherein, The first direct current electrode is located on one side of the first radio frequency electrode, and the second radio frequency electrode is located on the other side of the first radio frequency electrode; The first radio frequency electrode is located on one side of the second radio frequency electrode, and the second direct current electrode is located on the other side of the second radio frequency electrode.

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