Optical module

Abstract

An optical module (200). The optical module (200) comprises a circuit board (300) and a light emission component (400). The light emission component (400) comprises a substrate (910), a laser chip (920), and an adapter board (980). The power supply connection and signal connection between the substrate (910) and the laser chip (920) are achieved by means of the adapter board (980), thereby avoiding the use of wire bonding to achieve the connection between the substrate (910) and the laser chip (920). The laser chip (920) comprises a first optical waveguide (9212), a second optical waveguide (9214), and a third optical waveguide (9213). The passive third optical waveguide (9213) is butt-joined to the second optical waveguide (9214) at an output end of the first optical waveguide (9212); and the transition connection between the first optical waveguide (9212) and the second optical waveguide (9214) is achieved by means of the third optical waveguide (9213), so as to reduce the end face reflection between the first optical waveguide (9212) and the second optical waveguide (9214). By controlling the thickness and width of a waveguide core layer (9226) in the second optical waveguide (9214), the effective refractive index difference between the waveguide core layer (9226) and a cladding layer of the second optical waveguide (9214) is made smaller than the effective refractive index difference between a waveguide core layer (9221) and a cladding layer of the first optical waveguide (9212), so as to optimize the spot shape and far-field divergence angle of the laser chip (920).

Description

optical modules

[0001] This application claims the priority of application number 202311739764.8 filed with the China Patent Office on December 15, 2023; the priority of application number 202311732733.X filed with the China Patent Office on December 15, 2023, all of which are incorporated by reference into this application. Technical Field

[0002] The present disclosure relates to the field of optical fiber communication technology, and in particular to an optical module. Background Art

[0003] Optical communication technology is used in new business models and applications such as cloud computing, mobile internet, and video. In optical communications, optical modules are tools for converting optical and electrical signals and are key components in optical communication equipment. With the rapid development of 5G networks, optical modules, at the core of optical communications, have experienced significant development.

[0004] Summary of the Invention

[0005] The optical module provided by the present disclosure includes: a circuit board and a light emitting component. The light emitting component is electrically connected to the circuit board and is used to generate and output an optical signal; wherein the light emitting component includes:

[0006] A substrate, with a power supply line and a high-frequency signal line formed on the surface;

[0007] A laser chip is disposed on the substrate, and the laser chip includes:

[0008] a light emitting area, electrically connected to the power supply line, the light emitting area being configured to generate a light beam;

[0009] a modulation area electrically connected to the high-frequency signal line, the modulation area being connected to the light-emitting area, and the modulation area being configured to modulate the light beam;

[0010] a first optical waveguide coupled to the modulation zone, wherein a waveguide core layer of the first optical waveguide has a first width and a first thickness, and the first optical waveguide is configured to transmit modulated light output by the modulation zone;

[0011] a second optical waveguide that does not match the mode field of the first optical waveguide, wherein the waveguide core of the second optical waveguide has a second width and a second thickness, wherein the second width is smaller than the first width, and the second thickness is smaller than the first thickness, so as to reduce the effective refractive index of the waveguide core of the second optical waveguide and reduce the effective refractive index difference between the waveguide core and the cladding of the second optical waveguide;

[0012] a third optical waveguide, wherein a light input end is coupled to the light output end of the first optical waveguide, a light output end of the third optical waveguide is coupled to the second optical waveguide, and the third optical waveguide is configured to achieve a transition connection between the first optical waveguide and the second optical waveguide;

[0013] An adapter plate, whose two ends are respectively fixed to the surface of the substrate and the surface of the laser chip, and a conductive line and a signal line are respectively formed on the surface of the adapter plate; one end of the conductive line is electrically connected to the power supply line, and the other end of the conductive line is electrically connected to the light-emitting area to achieve a power supply connection between the substrate and the laser chip; one end of the signal line is electrically connected to the high-frequency signal line, and the other end of the signal line is electrically connected to the modulation area to achieve a signal connection between the substrate and the laser chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0015] FIG1 is a partial structural diagram of an optical communication system provided according to some embodiments of the present disclosure;

[0016] FIG2 is a partial structural diagram of a host computer provided according to some embodiments of the present disclosure;

[0017] FIG3 is a structural diagram of an optical module provided according to some embodiments of the present disclosure;

[0018] FIG4 is an exploded view of an optical module according to some embodiments of the present disclosure;

[0019] FIG5 is a structural diagram of a light emitting component in an optical module according to some embodiments of the present disclosure;

[0020] FIG6 is an exploded view of a light emitting component in an optical module according to some embodiments of the present disclosure;

[0021] FIG7 is a first structural diagram of a laser chip in an optical module according to some embodiments of the present disclosure;

[0022] FIG8 is a connection diagram of a circuit board and a laser chip in an optical module according to some embodiments of the present disclosure;

[0023] FIG9 is a partial connection diagram 1 of a circuit board and a laser chip in an optical module according to some embodiments of the present disclosure;

[0024] FIG10 is an assembly diagram of a laser chip and a substrate in an optical module according to some embodiments of the present disclosure;

[0025] FIG11 is a top view of a laser chip in an optical module according to some embodiments of the present disclosure;

[0026] FIG12 is a structural diagram of an adapter board in an optical module according to some embodiments of the present disclosure;

[0027] FIG13 is an assembly diagram of a substrate, a laser chip, and an adapter plate in an optical module according to some embodiments of the present disclosure;

[0028] FIG14 is a first perspective view of an assembly of a substrate, a laser chip, and an adapter plate in an optical module according to some embodiments of the present disclosure;

[0029] FIG15 is a second perspective view of an assembly of a substrate, a laser chip, and an adapter plate in an optical module according to some embodiments of the present disclosure;

[0030] FIG16 is a second partial connection diagram of a circuit board and a laser chip in an optical module according to some embodiments of the present disclosure;

[0031] FIG17 is a second structural diagram of a laser chip in an optical module according to some embodiments of the present disclosure;

[0032] FIG18a is a structural diagram of a deep-etched waveguide in an optical module according to some embodiments of the present disclosure;

[0033] FIG18b is a schematic diagram of a mode spot of an optical waveguide in an optical module according to some embodiments of the present disclosure;

[0034] FIG18c is a first graph showing a lateral divergence angle curve of a laser chip in an optical module according to some embodiments of the present disclosure;

[0035] FIG18 d is a first graph showing a longitudinal divergence angle curve of a laser chip in an optical module according to some embodiments of the present disclosure;

[0036] FIG19 is a third structural diagram of a laser chip in an optical module according to some embodiments of the present disclosure;

[0037] FIG20 is a partial top view of a laser chip in an optical module according to some embodiments of the present disclosure;

[0038] FIG21 is a top view of a partial structure of a laser chip in an optical module according to some embodiments of the present disclosure;

[0039] FIG22 is a waveguide structure diagram of a laser chip in an optical module according to some embodiments of the present disclosure;

[0040] Figure 23a is a cross-sectional view at AA in Figure 21;

[0041] Figure 23b is a cross-sectional view at CC in Figure 21;

[0042] Figure 23c is a cross-sectional view at point BB in Figure 21;

[0043] FIG24a is a first diagram showing a transmittance relationship of a transition optical waveguide in an optical module according to some embodiments of the present disclosure;

[0044] FIG24 b is a second diagram showing the transmittance relationship of a transition optical waveguide in an optical module according to some embodiments of the present disclosure;

[0045] FIG24c is a third diagram showing the transmittance relationship of a transition optical waveguide in an optical module according to some embodiments of the present disclosure;

[0046] FIG25 a is a first diagram showing simulation results of the overall far-field morphology of a laser chip in an optical module according to some embodiments of the present disclosure;

[0047] FIG25 b is a second simulation result of the overall far-field morphology of a laser chip in an optical module according to some embodiments of the present disclosure;

[0048] FIG25c is a second graph showing a lateral divergence angle curve of a laser chip in an optical module according to some embodiments of the present disclosure;

[0049] FIG25 d is a second graph showing a longitudinal divergence angle curve of a laser chip in an optical module according to some embodiments of the present disclosure. DETAILED DESCRIPTION

[0050] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in some embodiments of the present disclosure. Obviously, the embodiments described are only some embodiments of the present disclosure, not all embodiments. Based on the embodiments provided by the present disclosure, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of the present disclosure.

[0051] Unless the context requires otherwise, throughout the specification and claims, the term "comprise" and its other forms, such as the third person singular form "comprises" and the present participle form "comprising", are to be interpreted as open and inclusive, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "example", "specific example" or "some examples" are intended to indicate that the particular features, structures, materials or characteristics associated with the embodiment or example are included in at least one embodiment or example of the present disclosure. The schematic representation of the above terms does not necessarily refer to the same embodiment or example. In addition, the particular features, structures, materials or characteristics may be included in any one or more embodiments or examples in any appropriate manner.

[0052] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, unless otherwise specified, "plurality" means two or more.

[0053] When describing some embodiments, the expressions "coupled" and "connected" and their derivatives may be used. For example, when describing some embodiments, the term "connected" may be used to indicate that two or more components are in direct physical or electrical contact with each other. For another example, when describing some embodiments, the term "coupled" may be used to indicate that two or more components are in direct physical or electrical contact. However, the term "coupled" or "communicatively coupled" may also refer to two or more components that are not in direct contact with each other, but still cooperate or interact with each other. The embodiments disclosed herein are not necessarily limited to the contents of this document.

[0054] “At least one of A, B and C” has the same meaning as “at least one of A, B or C” and both include the following combinations of A, B and C: A only, B only, C only, the combination of A and B, the combination of A and C, the combination of B and C, and the combination of A, B and C.

[0055] “A and / or B” includes the following three combinations: A only, B only, and a combination of A and B.

[0056] The use of "adapted to" or "configured to" herein is intended to be open and inclusive language that does not exclude devices adapted or configured to perform additional tasks or steps.

[0057] As used herein, "about," "substantially," or "approximately" includes the stated value and an average value that is within an acceptable range of deviation from the particular value as determined by one of ordinary skill in the art taking into account the measurements in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system).

[0058] Optical communication technology enables information transmission between information processing devices. It loads information onto light and uses the propagation of light to achieve this transmission. Light loaded with information is an optical signal. The propagation of optical signals within information transmission equipment reduces optical power loss, enabling high-speed, long-distance, and low-cost information transmission. The information processed by information processing equipment exists in the form of electrical signals. Optical network terminals / gateways, routers, switches, mobile phones, computers, servers, tablets, and televisions are common information processing devices, and optical fibers and optical waveguides are common information transmission devices.

[0059] The conversion of optical signals and electrical signals between information processing equipment and information transmission equipment is achieved through optical modules. For example, an optical fiber is connected to the optical signal input end and / or optical signal output end of the optical module, and an optical network terminal is connected to the electrical signal input end and / or electrical signal output end of the optical module. A first optical signal from the optical fiber is transmitted into the optical module, and the optical module converts the first optical signal into a first electrical signal, which is then transmitted into the optical network terminal. A second electrical signal from the optical network terminal is transmitted into the optical module, and the optical module converts the second electrical signal into a second optical signal, which is then transmitted into the optical fiber. Since information processing devices can be connected to each other through an electrical signal network, at least one type of information processing device needs to be directly connected to the optical module, and not all types of information processing devices need to be directly connected to the optical module. The information processing device directly connected to the optical module is called the host computer of the optical module.

[0060] Figure 1 is a partial architecture diagram of an optical communication system according to some embodiments of the present disclosure. As shown in Figure 1, the optical communication system partially comprises a remote information processing device 1000, a local information processing device 2000, a host computer 100, an optical module 200, an optical fiber 101, and a network cable 103.

[0061] One end of optical fiber 101 extends toward remote information processing device 1000, and the other end connects to the optical interface of optical module 200. Optical signals can undergo total internal reflection within optical fiber 101, maintaining nearly their original optical power as they propagate in the direction of total internal reflection. Multiple total internal reflections within optical fiber 101 transmit optical signals from the direction of remote information processing device 1000 into optical module 200, or transmit light from optical module 200 toward remote information processing device 1000, enabling long-distance, low-power information transmission.

[0062] The number of optical fibers 101 may be one or more (two or more); the optical fiber 101 and the optical module 200 may be connected in a pluggable movable manner or in a fixed manner.

[0063] The host computer 100 has an optical module interface 102, which is configured to connect to the optical module 200, so that the host computer 100 establishes a unidirectional / bidirectional electrical signal connection with the optical module 200; 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 and control the working status of the optical module 200.

[0064] The host computer 100 has an external electrical interface, such as a Universal Serial Bus (USB) interface and a network cable interface 104, which can be connected to an electrical signal network. For example, the network cable interface 104 is configured to connect to a network cable 103, thereby establishing a unidirectional / bidirectional electrical signal connection between the host computer 100 and the network cable 103.

[0065] Optical Network Unit (ONU), Optical Line Terminal (OLT), Optical Network Equipment (ONT) and data center servers are common host computers.

[0066] 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 . The network cable 103 establishes an electrical signal connection between the local information processing device 2000 and the host computer 100 .

[0067] For example, the 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 into the optical module 200. The optical module 200 converts the second electrical signal into a second optical signal. The optical module 200 transmits the second optical signal into the optical fiber 101. The second optical signal is transmitted to the remote information processing device 1000 in the optical fiber 101.

[0068] For example, a first optical signal from the direction of the remote information processing device 1000 propagates through the optical fiber 101, and the first optical signal from the optical fiber 101 is transmitted into the optical module 200. The optical module 200 converts the first optical signal into a first electrical signal. The optical module 200 transmits the first electrical signal into the host computer 100. The host computer 100 generates a fourth electrical signal based on the first electrical signal, and the host computer 100 transmits the fourth electrical signal to the local information processing device 2000.

[0069] Optical modules are tools for converting optical signals into electrical signals. During this conversion process, the information remains unchanged, but the encoding and decoding methods of the information can change.

[0070] FIG2 is a partial structural diagram of a host computer provided according to some embodiments of the present disclosure. In order to clearly illustrate the connection relationship between the optical module 200 and the host computer 100, FIG2 only shows the structure of the host computer 100 related to the optical module 200. As shown in FIG2, the host computer 100 includes a PCB circuit board 105 disposed within a housing, a cage 106 disposed on the surface of the PCB circuit board 105, a heat sink 107 disposed on the cage 106, and an electrical connector (not shown) disposed within the cage 106. The heat sink 107 has a raised structure that increases the heat dissipation area. A fin-like structure is a common raised structure.

[0071] Optical module 200 is inserted into cage 106 of host computer 100. Cage 106 secures optical module 200, and heat generated by optical module 200 is transferred to cage 106 and then dissipated through heat sink 107. After optical module 200 is inserted into cage 106, the electrical interface of optical module 200 connects to the electrical connector inside cage 106.

[0072] Figure 3 is a structural diagram of an optical module provided according to some embodiments of the present disclosure, and Figure 4 is an exploded view of an optical module provided according to some embodiments of the present disclosure. As shown in Figures 3 and 4, the optical module 200 includes a housing, a circuit board 300 disposed within the housing, and a light emitting component 400 and a light receiving component 500 disposed within the housing. However, the present disclosure is not limited thereto. In some embodiments, the optical module 200 includes either the light emitting component 400 or the light receiving component 500.

[0073] The housing includes an upper housing 201 and a lower housing 202 . The upper housing 201 covers the lower housing 202 to form the housing having two openings 204 and 205 . The outer contour of the housing is generally a square.

[0074] In some embodiments, the lower shell 202 includes a base plate 2021 and two lower side plates 2022 located on both sides of the base plate 2021 and arranged perpendicular to the base plate 2021; the upper shell 201 includes a cover plate 2011, and the cover plate 2011 covers the two lower side plates 2022 of the lower shell 202 to form the above-mentioned shell.

[0075] In some embodiments, the lower shell 202 includes a base plate 2021 and two lower side plates 2022 located on both sides of the base plate 2021 and arranged perpendicularly to the base plate 2021; the upper shell 201 includes a cover plate 2011 and two upper side plates located on both sides of the cover plate 2011 and arranged perpendicularly to the cover plate 2011. The two upper side plates are combined with the two lower side plates 2022 to achieve the upper shell 201 covering the lower shell 202.

[0076] The direction of the line connecting the two openings 204 and 205 can be aligned with or inconsistent with the length of the optical module 200 (e.g., the direction indicated by the x-axis in FIG3 ). For example, opening 204 is located at the right end of the optical module 200 (the positive end of the x-axis in FIG3 ), and opening 205 is also located at the left end of the optical module 200 (the negative end of the x-axis in FIG3 ). Alternatively, opening 204 is located at the end of the optical module 200, while opening 205 is located at the side of the optical module 200. Opening 204 is an electrical port, from which the gold finger 301 of the circuit board 300 extends and is inserted into the electrical connector of the host computer 100. Opening 205 is an optical port, configured to receive an external optical fiber 101, thereby connecting the optical fiber 101 to the optical emitting component 400 and the optical receiving component 500 in the optical module 200. In some embodiments, the x-axis in FIG3 is the left-right direction.

[0077] The combined assembly of 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, and the like within the housing. The upper housing 201 and the lower housing 202 provide encapsulation and protection for these components. Furthermore, during assembly of the circuit board 300, the light emitting component 400, and the light receiving component 500, the positioning components, heat dissipation components, and electromagnetic shielding components of these components are easily positioned, facilitating automated production.

[0078] In some embodiments, the upper shell 201 and the lower shell 202 are made of metal materials, which facilitates electromagnetic shielding and heat dissipation.

[0079] In some embodiments, the optical module 200 includes an unlocking component 600 located outside its housing. The unlocking component 600 is configured to achieve 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.

[0080] For example, the unlocking component 600 is located on the outside of the two lower side panels 2022 of the lower housing 202 and includes a snap-fit ​​component that mates with the cage 106 of the host computer 100. When the optical module 200 is inserted into the cage 106, the snap-fit ​​component of the unlocking component 600 secures the optical module 200 in the cage 106. When the unlocking component 600 is pulled, the snap-fit ​​component of the unlocking component 600 moves accordingly, thereby changing the connection between the snap-fit ​​component and the host computer, thereby releasing the optical module 200 from the cage 106 and allowing the optical module 200 to be removed from the cage 106.

[0081] The circuit board 300 includes circuit traces, electronic components, and chips. The electronic components and chips are connected according to the circuit design through the circuit traces to achieve 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, for example, 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.

[0082] The circuit board 300 is generally a rigid circuit board. Due to its relatively hard material, the rigid circuit board can also realize the load-bearing function. For example, the rigid circuit board can stably carry the above-mentioned electronic components and chips; the rigid circuit board can also be inserted into the electrical connector in the cage 106 of the host computer 100.

[0083] The circuit board 300 includes a gold finger 301 formed on its end surface, and the gold finger 301 is composed of a plurality of independent pins. The circuit board 300 is inserted into the cage 106, and the gold finger 301 is connected to the electrical connector in the cage 106. The gold finger 301 can be set only on the surface of one side of the circuit board 300 (for example, the upper surface shown in Figure 4), or it can be set on the upper and lower surfaces of the circuit board 300 to provide a larger number of pins, thereby adapting to occasions where a large number of pins are required. The gold finger 301 is configured to establish an electrical connection with the host computer to achieve power supply, grounding, two-wire synchronous serial (Inter-Integrated Circuit, I2C) signal transmission, data signal transmission, etc. Of course, flexible circuit boards are also used in some optical modules. Flexible circuit boards are generally used in conjunction with rigid circuit boards to supplement rigid circuit boards.

[0084] At least one of the light emitting component 400 or the light receiving component 500 is located on a side of the circuit board 300 away from the gold finger 301 .

[0085] 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.

[0086] In some embodiments, at least one of the light emitting component 400 or the light receiving component 500 may be directly disposed on the circuit board 300. For example, at least one of the light emitting component 400 or the light receiving component 500 may be disposed on a surface of the circuit board 300 or a side of the circuit board 300.

[0087] 4 , the optical module provided by the embodiment of the present disclosure includes a square tube body 1100 , on which a light emitting component 400 and a light receiving component 500 are arranged. The light emitting component 400 is used to generate and output signal light, and the light receiving component 500 is used to receive signal light from outside the optical module.

[0088] The rectangular tube 1100 is provided with a fiber optic adapter for connecting the optical module to an external optical fiber. A lens assembly is typically provided within the rectangular tube 1100 for changing the propagation direction of the output signal light from the optical transmitter 400 or the input signal light from the external optical fiber. The optical transmitter 400 and optical receiver 500 are physically separated from the circuit board 300, making it difficult to directly connect the optical transmitter 400 and optical receiver 500 to the circuit board 300. In this application, the optical transmitter 400 and optical receiver 500 are electrically connected via a flexible printed circuit board and the circuit board 300, respectively.

[0089] 4 , light emitting component 400 is disposed on square tube 1100 and is coaxial with the fiber optic adapter of square tube 1100, while light receiving component 500 is disposed on the side of square tube 1100 and is not coaxial with the fiber optic adapter of square tube 1100. In some embodiments, light emitting component 400 may be coaxial with the fiber optic adapter, while light receiving component 500 may be coaxial with the fiber optic adapter.

[0090] Placing the optical transmitter 400 and optical receiver 500 within the rectangular tube 1100 facilitates control of the signal light transmission path and a compact design within the optical module, reducing the space occupied by the signal light transmission path. Furthermore, with the advancement of wavelength division multiplexing technology, some optical modules incorporate more than one optical transmitter 400 and receiver 500 within the rectangular tube 1100.

[0091] In some embodiments, a reflective mirror is also provided in the square tube body 1100, which changes the propagation direction of the signal light to be received by the light receiving component 500, or changes the propagation direction of the signal light generated by the light emitting component 400, so as to facilitate the light receiving component 500 to receive the signal light or the output of the signal light generated by the light emitting component 400.

[0092] In some embodiments, the assembly structure of the light emitting component 400 and the light receiving component 500 is not limited to the structure shown in Figures 3 and 4, and can also be other assembly combination structures, such as the light emitting component 400 and the light receiving component 500 are set on different tube bodies. This embodiment only takes the structure shown in Figures 3 and 4 as an example.

[0093] Figure 5 is a structural diagram of a light emitting component in an optical module according to some embodiments of the present disclosure, Figure 6 is an exploded view of a light emitting component in an optical module according to some embodiments of the present disclosure, and Figure 7 is a structural diagram of a laser chip in an optical module according to some embodiments of the present disclosure. As shown in Figures 5, 6, and 7, the light emitting component 400 provided in the embodiments of the present disclosure includes a tube base 410, a tube cap 420, and other optoelectronic devices disposed within the tube base 410 and the tube cap 420. The tube cap 420 is disposed on one end of the tube base 410. The tube base 410 is provided with a number of pins, which are used to electrically connect the flexible circuit board to the optoelectronic devices within the light emitting component 400, thereby electrically connecting the light emitting component 400 to the circuit board 300. This embodiment only uses the structure shown in Figure 5 as an example.

[0094] The optoelectronic device on the tube base 410 includes a laser assembly 900, which is used to generate signal light. The signal light is emitted into the square tube body 1100 through the tube cap 420, and the signal light is then transmitted to the fiber optic adapter through the square tube body 1100 to transmit the signal light to the external optical fiber.

[0095] 7 , the laser assembly 900 includes a substrate 910 and a laser chip 920 . A circuit is laid on the upper surface of the substrate 910 . The laser chip 920 is connected to the circuit on the substrate 910 by bonding wires, so that the laser chip 920 generates signal light.

[0096] In some embodiments, the laser chip 920 may be an electro-absorption module laser (EML) chip. The EML laser chip, the substrate 910, and the bonding wires between the EML laser chip and the substrate 910 form an EML laser assembly.

[0097] In some embodiments, the EML laser chip may include a light-emitting region. A light-emitting electrode is disposed on a surface of the EML laser chip. The light-emitting electrode is electrically connected to the light-emitting region to transmit a bias current to the light-emitting region through the light-emitting electrode, thereby causing the light-emitting region to generate a laser beam.

[0098] In some embodiments, the EML laser chip may include a modulation region. Modulation electrodes are provided on the surface of the EML laser chip. The modulation electrodes are electrically connected to the modulation region, transmitting a modulation current signal to the modulation region via the modulation electrodes. This causes the modulation region to modulate the laser beam and the modulation current signal. In other words, the light emitted by the light-emitting region varies according to the modulation current signal, thereby achieving modulation and producing a modulated light signal.

[0099] In the embodiment of the present disclosure, the structure of the laser assembly 900 is not limited to the structure shown in Figure 7, and may also be a laser assembly formed of other structures. The substrate 910 may be a ceramic substrate, but is not limited to a ceramic substrate.

[0100] Figure 8 shows a connection diagram between a circuit board and a laser chip in an optical module according to some embodiments of the present disclosure, and Figure 9 shows a partial connection diagram of a circuit board and a laser chip in an optical module according to some embodiments of the present disclosure. As shown in Figures 8 and 9, a DSP chip is mounted on the surface of circuit board 300 for transmitting optical signals.

[0101] In some embodiments, the DSP chip is connected to the gold finger 301 via a signal line, and the electrical signal provided by the host computer 100 is transmitted to the DSP chip via the gold finger 301 .

[0102] The surface of the circuit board 300 is provided with drive signal lines, which extend from the DSP chip to the edge of the substrate 910. The drive signal lines transmit the high-frequency electrical signals output by the DSP chip to the light emitting component 400, thereby driving the laser chip 920 of the light emitting component 400 to generate optical signals.

[0103] In some embodiments, the electrical signal output by the DSP chip may be a differential signal, and the driving signal line on the circuit board 300 is a differential signal line. The differential signal line includes a first differential signal line 302 and a second differential signal line 303. The first differential signal line 302 is connected to the high-frequency signal line 9103 by bonding, and the second differential signal line 303 is connected to the ground conductive area 9100 on the substrate 910 by bonding, so as to transmit the high-speed electrical signal output by the DSP chip to the high-frequency signal line 9103 through the differential signal line.

[0104] In some embodiments, in order to provide a flat optical bearing surface for the laser chip 920 , the laser chip 920 may be mounted on the substrate 910 .

[0105] In some embodiments, a power supply line 9104 is disposed on the surface of the substrate 910 and is configured to provide a bias current to the light emitting area of ​​the laser chip 920 .

[0106] The circuit board 300 is provided with an electrical pad 305. One end of a power supply line 9104 is electrically connected to the pad 305 via a bonding wire, while the other end of the power supply line 9104 is also electrically connected to the light-emitting area of ​​the laser chip 920 via a bonding wire. The bias current transmitted by the circuit board 300 is transmitted to the light-emitting area of ​​the laser chip 920 via the power supply line 9104, thereby driving the light-emitting area of ​​the laser chip 920 to generate a laser beam.

[0107] In some embodiments, a high-frequency signal line 9103 is disposed on the surface of the substrate 910 , and is configured to provide a modulation current signal to the modulation region of the laser chip 920 .

[0108] One end of the high-frequency signal line 9103 is connected to the drive signal line on the circuit board 300 to transmit the electrical signal transmitted by the drive signal line to the high-frequency signal line 9103. The other end of the high-frequency signal line 9103 is wire-bonded to the modulation area of ​​the laser chip 920. The high-frequency modulated current signal output by the DSP chip is transmitted to the modulation area of ​​the laser chip 920 via the high-frequency signal line 9103 to modulate the light emitted by the light-emitting area, causing the laser chip 920 to generate a modulated light signal.

[0109] In some embodiments, to facilitate high-speed signal return, the circuit board 300 is further provided with a ground pad. A grounding region is provided on the surface of the substrate 910. The bottom surface of the laser chip 920 is mounted on the grounding region. The power supply line 9104 is not connected to the high-frequency signal line 9103 or the grounding region. The ground pad on the circuit board 300 is connected to the grounding region via bonding wires, thereby grounding the grounding region.

[0110] The RC parasitic parameters of laser chip 920 itself significantly affect the frequency response of the optical emitting component. The bonding wires between laser chip 920 and substrate 910 also affect the frequency response of laser chip 920. In particular, when the parasitic capacitance of laser chip 920 causes the chip bandwidth to be low, the performance of laser chip 920 is severely affected. For example, this can cause the rising edge of the eye diagram to slow down, the eye diagram to not open, and inter-symbol interference, thereby reducing the high-frequency response bandwidth of laser chip 920. For example, RF design methods cannot meet performance requirements, and certain bandwidth compensation technologies are needed to increase the high-frequency response bandwidth of laser chip 920 to compensate for the performance deficiencies of the optical chip itself.

[0111] Figure 10 shows an assembly diagram of a laser chip and substrate in an optical module according to some embodiments of the present disclosure, and Figure 11 shows a top view of a laser chip in an optical module according to some embodiments of the present disclosure. As shown in Figures 10 and 11, the laser assembly 900 provided in the present disclosure includes a substrate 910 and a laser chip 920.

[0112] To improve the high-frequency response bandwidth of laser chip 920, a grounded conductive region 9100 is formed on the upper surface of substrate 910. Laser chip 920 is disposed on the surface of grounded conductive region 9100. In some embodiments, grounded conductive region 9100 surrounds high-frequency signal line 9103, providing a return ground for the current carried by high-frequency signal line 9103. This helps reduce signal noise, thereby improving the high-frequency response bandwidth of laser chip 920.

[0113] In some embodiments, a first relief portion 9112 may be formed on the surface of the ground conductive region 9100. The first relief portion 9112 has an opening at one end facing the circuit board 300. A power supply line 9104 is disposed within the first relief portion 9112. One end of the power supply line 9104 is electrically connected to a power supply pad on the circuit board 300, and the other end of the power supply line 9104 is connected to the light-emitting region of the laser chip 920 to provide a bias current transmitted by the power supply line 9104 to the light-emitting region of the laser chip 920, causing the light-emitting region to generate a laser beam. The power supply lines 9104 may include a first power supply line 9108, a second power supply line 9109, and a third power supply line 9110.

[0114] Referring to the orientation shown in FIG10 , the laser chip 920 is positioned at the upper right corner of the ground conductive region 9100. A power supply line 9104 extends from the left side of the substrate 910 (the negative end of the X-axis shown in FIG10 ) along the positive X-axis to the laser chip 920. In some embodiments, the X-axis shown in FIG9 represents the left-right direction, the Y-axis represents the up-down direction, and the Z-axis represents the thickness direction.

[0115] Referring to Figure 11 , a light-emitting electrode 9201 is formed on the top surface of the laser chip 920. This electrode is connected to the light-emitting region of the laser chip 920. One end of a power supply line 9104 is connected to this electrode, and the other end of this line is electrically bonded to a power supply pad on the circuit board 300. A bias current from the circuit board 300 is transmitted via this line to the light-emitting electrode 9201, providing a bias current to the light-emitting region of the laser chip 920, causing it to generate a laser beam without a signal.

[0116] In some embodiments, a second relief portion 9113 may be formed on the surface of the ground conductive region 9100. The second relief portion 9113 also has an opening on the end facing the circuit board 300. A high-frequency signal line 9103 is disposed within the second relief portion 9113. One end of the high-frequency signal line 9103 is wire-bonded to a drive signal line on the circuit board 300, and the other end of the high-frequency signal line 9103 is connected to the modulation region of the laser chip 920. This allows the current signal transmitted by the drive signal line to be transmitted to the modulation region via the high-frequency signal line 9103, causing the laser chip 920 to generate a modulated optical signal.

[0117] In some embodiments, referring to FIG. 11 , a modulation electrode 9202 is further provided on the top surface of the laser chip 920. The modulation electrode 9202 is connected to the modulation region of the laser chip 920 and is also connected to the high-frequency signal line 9103. The high-frequency modulation current signal output by the DSP chip is transmitted to the modulation electrode 9202 via the drive signal line and the high-frequency signal line 9103, thereby providing a modulation current signal to the modulation region of the laser chip 920. This causes the modulation region to modulate the laser beam generated by the light-emitting region to output a modulated light signal.

[0118] In some embodiments, the light emitting electrode 9201 of the laser chip 920 is located on one side of the modulation electrode 9202. Referring to the direction shown in FIG9 , the light emitting electrode 9201 of the laser chip 920 is located on the left side of the modulation electrode 9202.

[0119] In some embodiments, the light emitting end face of the laser chip 920 is located on one side of the laser chip 920. Referring to the direction shown in FIG9 , the light emitting end face of the laser chip 920 is located on the right side of the laser chip 920, and the light emitting direction of the laser chip 920 is along the positive direction of the X-axis.

[0120] In some embodiments, because the light-emitting electrode 9201 of the laser chip 920 is located to the left of the modulation electrode 9202, the length of the power supply line 9104 on the substrate 910 along the X-axis is shorter than the length of the high-frequency signal line 9103. The right end of the power supply line 9104 can be aligned with the light-emitting electrode 9201 along the X-axis, and the right end of the power supply line 9104 can also be aligned with the light-emitting electrode 9201 along the Y-axis. The right end of the high-frequency signal line 9103 can be aligned with the modulation electrode 9202 along the Y-axis.

[0121] In some embodiments, a third escape portion 9114 may be formed on the surface of the ground conductive region 9100. The third escape portion 9114 also has an opening at one end facing the circuit board 300. The third escape portion 9114 is located between the first escape portion 9112 and the second escape portion 9113. The third escape portion 9114 is connected to the second escape portion 9113.

[0122] A resistor pad 9106 is disposed in the third avoiding portion 9114 , and the resistor pad 9106 is wire-bonded to the second differential signal line 303 on the circuit board 300 .

[0123] In some embodiments, a certain gap exists between the resistor pad 9106 and the ground conductive region 9100. A first resistor 9107 is disposed between the resistor pad 9106 and the ground conductive region 9100. One end of the first resistor 9107 is connected to the resistor pad 9106, and the other end of the first resistor 9107 is connected to the ground conductive region.

[0124] First resistor 9107 performs impedance matching, ultimately aligning the impedance output by the EML laser chip with the characteristic impedance of first resistor 910. Therefore, first resistor 9107 can be called a matching resistor. Due to the limited space on substrate 910, first resistor 9107 is typically a thin-film resistor, sintered within a single area of ​​substrate 910.

[0125] In some embodiments, the first differential signal line 302 is wire-bonded to the high-frequency signal line 9103 to transmit the high-frequency electrical signal transmitted by the first differential signal line 302 to the high-frequency signal line 9103. The second differential signal line 303 is wire-bonded to the resistor pad 9106, which is connected to the first resistor 9107. The first resistor 9107 is connected to the ground conductive region 9100 to ground the second differential signal line 303.

[0126] Referring to the direction shown in FIG10 , the first relief portion 9112 extends from the left end of the substrate 910 (the negative end of the X-axis shown in FIG10 ) to the right end of the substrate 910 (the positive end of the X-axis shown in FIG10 ); the second relief portion 9113 extends from the left end of the substrate 910 to the right end of the substrate 910; and the length of the third relief portion 9114 in the X-axis direction is smaller than the length of the second relief portion 9113. The second relief portion 9113 is connected to the third relief portion 9114, and the second relief portion 9113 may or may not be connected to the first relief portion 9112.

[0127] In some embodiments, the first avoidance portion 9112 and the second avoidance portion 9113 divide the ground conductive region 9100 into a first ground conductive region 9101, a second ground conductive region 9111, and a third ground conductive region 9102. The first ground conductive region 9101, the second ground conductive region 9111, and the third ground conductive region 9102 are sequentially arranged along the negative direction (vertical direction) of the Y-axis.

[0128] Referring to Figure 9 , ground pads are also provided on the circuit board 300. These include a first ground pad 304 and a second ground pad 306. The first and second ground pads 304 and 306 are located on either side of the first differential signal line 302 and the second differential signal line 303. The first ground pad 304 is connected to the first ground conductive region 9101 or the second ground conductive region 9111 via bonding wires, while the second ground pad 306 is connected to the third ground conductive region 9102 via bonding wires, thereby enabling signal return of high-frequency electrical signals.

[0129] In some embodiments, the laser chip 920 can be electrically connected to the substrate 910 using wire bonding. For example, referring to Figures 9 and 10 , after laying out a power supply line 9104 and a high-frequency signal line 9103 on the substrate 910, the laser chip 920 is mounted on the substrate 910, for example, on the first ground conductive region 9101. One end of the power supply line 9104 is then wire-bonded to the electrical pad 305, and the other end of the power supply line 9104 is wire-bonded to the light-emitting electrode 9201 on the top surface of the laser chip 920 to supply power to the light-emitting region of the laser chip 920, causing the region to generate a laser beam. One end of the high-frequency signal line 9103 is then wire-bonded to the first differential signal line 302, and the other end of the high-frequency signal line 9103 is wire-bonded to the modulation electrode 9202 on the top surface of the laser chip 920 to provide a modulation current signal to the modulation region of the laser chip 920, causing the modulation region to modulate the laser beam, generating a modulated optical signal.

[0130] When connecting the laser chip 920 and substrate 910 via wire bonding, the wire bonding introduces inductive reactance into the circuit, causing an impedance mismatch between the high-frequency signal line 9103 and the laser chip 920, thereby affecting the signal bandwidth. To mitigate the impedance mismatch caused by wire bonding, the optical emitting component 400 provided in the present embodiment includes an adapter plate. This adapter plate enables electrical connection between the laser chip 920 and substrate 910.

[0131] In some embodiments, one end of the adapter plate is electrically connected to the laser chip 920, and the other end is electrically connected to the substrate 910, thereby achieving electrical connection between the laser chip 920 and the substrate 910, thereby avoiding achieving electrical connection between the laser chip 920 and the substrate 910 through wire bonding, and further improving the high-frequency response function of the laser chip 920.

[0132] For example, one end of the adapter plate is welded to the laser chip 920 in a flip-chip manner, and the other end of the adapter plate is welded to the substrate 910 in a flip-chip manner, so that the connection between the laser chip 920 and the substrate 910 is achieved through the adapter plate, thereby solving problems such as impedance mismatch caused by wiring.

[0133] Figure 12 is a structural diagram of an adapter board in an optical module provided according to some embodiments of the present disclosure, Figure 13 is an assembly diagram of a substrate, a laser chip, and an adapter board in an optical module provided according to some embodiments of the present disclosure, and Figure 14 is a perspective view of the assembly of a substrate, a laser chip, and an adapter board in an optical module provided according to some embodiments of the present disclosure. As shown in Figures 12, 13, and 14, the adapter board 980 is located above the substrate 910. A grounded conductive layer 9800 is formed on the side (bottom) of the adapter board 980 facing the substrate 910. Exemplarily, the adapter board 980 can be a ceramic board.

[0134] In some embodiments, a fourth avoidance portion 9812 and a fifth avoidance portion 9813 are formed on the surface of the ground conductive layer 9800. The fourth avoidance portion 9812 and the fifth avoidance portion 9813 are not connected.

[0135] A conductive wire 9801 is disposed in the fourth avoidance portion 9812 . The conductive wire 9801 is configured to achieve a power supply connection between the substrate 910 and the laser chip 920 .

[0136] There is a gap between the conductive line 9801 and the ground conductive layer 9800 , so that the conductive line 9801 is not connected to the ground conductive layer 9800 .

[0137] When the right end of the power supply line 9104 is flush with the light-emitting electrode 9201 in the X-axis direction, the conductive line 9801 is set along the X-axis direction, and the adapter plate 980 is installed upside down on the top surface of the laser chip 920, and the adapter plate 980 covers part of the power supply line 9104.

[0138] One end of the conductive wire 9801 is electrically connected to the power supply line 9104 on the substrate 910, and the other end is electrically connected to the light-emitting area of ​​the laser chip 920, thereby realizing the electrical connection between the power supply line 9104 and the light-emitting area, and then realizing the power supply connection between the substrate 910 and the laser chip 920 through the adapter plate 980.

[0139] The power supply line 9104 provides a bias current to the light-emitting area through the conductive line 9801 on the adapter plate 980 , so that the light-emitting area of ​​the laser chip 920 generates a laser beam.

[0140] Exemplarily, the right end of power supply line 9104 is disposed correspondingly to the left end of conductive line 9801, and the light-emitting electrode 9201 of laser chip 920 is disposed correspondingly to the right end of conductive line 9801. Thus, the right end of power supply line 9104 is welded to the left end of conductive line 9801, and the right end of conductive line 9801 is welded to light-emitting electrode 9201. This electrically connects light-emitting electrode 9201 and power supply line 9104 via conductive line 9801 on adapter plate 980, thereby providing a bias current to light-emitting electrode 9201 via adapter plate 980, causing the light-emitting region of laser chip 920 to generate a laser beam. In some embodiments, the X-axis shown in Figures 12 and 14 represents the left-right direction, and the Y-axis represents the up-down direction.

[0141] 12 , when the right end of the power supply line 9104 is flush with the light-emitting electrode 9201 in the Y-axis direction, the conductive wire 9801 is arranged along the Y-axis direction, and the adapter plate 980 is installed upside down on the top surface of the laser chip 920. The adapter plate 980 covers part of the power supply line 9104, and the right end of the power supply line 9104 is arranged corresponding to the lower end of the conductive wire 9801. The light-emitting electrode 9201 of the laser chip 920 is arranged corresponding to the upper end of the conductive wire 9801. In this way, the right end of the power supply line 9104 is welded to the lower end of the conductive wire 9801, and the upper end of the conductive wire 9801 is welded to the light-emitting electrode 9201, so as to realize the electrical connection between the light-emitting electrode 9201 and the power supply line 9104 through the conductive wire 9801 on the adapter plate 980, thereby providing a bias current to the light-emitting electrode 9201 through the adapter plate 980, so that the light-emitting area of ​​the laser chip 920 generates a laser beam.

[0142] In some embodiments, to reduce the length of the wire bond between power supply line 9104 and power supply pad 305, power supply line 9104 and power supply pad are aligned in the Y-axis direction. In this case, power supply line 9104 and light-emitting electrode 9201 may not be aligned in the X-axis or Y-axis direction. To reduce the area size of adapter plate 980, power supply line 9104 can be configured as a special-shaped line. Referring to Figure 10, power supply line 9104 includes a first power supply line 9108, a second power supply line 9109, and a third power supply line 9110.

[0143] In some embodiments, a first power line 9108 is arranged along the X-axis, a second power line 9109 is arranged along the Y-axis, and a third power line 9110 is arranged along the X-axis. The first power line 9108 and the second power line 9109 are located to the left of the laser chip 920, while the third power line 9110 is located below the laser chip 920. One end of the first power line 9108 is connected to one end of the second power line 9109, and the other end of the second power line 9109 is connected to one end of the third power line 9110. The other end of the third power line 9110 is located near the light-emitting area of ​​the laser chip 920. Thus, the first power line 9108, the second power line 9109, and the third power line 9110 form a Z-shaped power line.

[0144] In some embodiments, an adapter plate 980 is mounted upside down on the top surface of the laser chip 920, partially covering the third power supply line 9110. The right end of the third power supply line 9110 corresponds to the lower end of the conductive line 9801, and the light-emitting electrode 9201 of the laser chip 920 corresponds to the upper end of the conductive line 9801. In this way, the right end of the third power supply line 9110 is welded to the lower end of the conductive line 9801, and the upper end of the conductive line 9801 is welded to the light-emitting electrode 9201. This electrically connects the light-emitting electrode 9201 to the power supply line 9104 via the conductive line 9801 on the adapter plate 980. This provides a bias current to the light-emitting electrode 9201 through the adapter plate 980, causing the light-emitting region of the laser chip 920 to generate a laser beam.

[0145] In some embodiments, because the laser chip 920 is disposed on the top surface of the substrate 910, there is a thickness difference between the top surface of the laser chip 920 and the top surface of the substrate 910. Therefore, when the adapter plate 980 is mounted upside down on the top surface of the laser chip 920, a gap exists between the bottom surface of the adapter plate 980 and the top surface of the substrate 910. To solder the conductive wire 9801 on the adapter plate 980 to the power supply wire 9104, the gap between the conductive wire 9801 and the power supply wire 9104 can be filled with solder.

[0146] In some embodiments, referring to FIG. 10 , a first metal protrusion 970, such as a metal pillar, may also be provided at the right end of the third power supply line 9110. The first metal protrusion 970 is formed by extending the surface of the third power supply line 9110 along the Z-axis. The thickness of the first metal protrusion 970 along the Z-axis may be equal to or less than the thickness difference between the top surface of the laser chip 920 and the top surface of the substrate 910.

[0147] 14 , when the adapter plate 980 is placed upside down on the top surface of the laser chip 920 , one end of the conductive wire 9801 on the adapter plate 980 is directly welded to the light-emitting electrode 9201 , and the other end of the conductive wire 9801 is welded to the first metal protrusion 970 , so as to realize the power supply connection between the substrate 910 and the laser chip 920 through the adapter plate 980 .

[0148] In some embodiments, referring to FIG. 11 , the thickness of the first metal protrusion 970 in the Z-axis direction may also be greater than the thickness difference between the top surface of the laser chip 920 and the top surface of the substrate 910. In this case, a second metal protrusion 9206 is provided on the light-emitting electrode 9201. The second metal protrusion 9206 is formed by extending the surface of the light-emitting electrode 9201 along the Z-axis direction. The thickness of the second metal protrusion 9206 in the Z-axis direction is less than the thickness of the first metal protrusion 970.

[0149] In some embodiments, when the adapter plate 980 is placed upside down on top of the laser chip 920, one end of the conductive wire 9801 on the adapter plate 980 is welded to the second metal protrusion 9206, and the other end of the conductive wire 9801 is welded to the first metal protrusion 970, so as to realize the power supply connection between the substrate 910 and the laser chip 920 through the adapter plate 980.

[0150] In some embodiments, referring to Figures 10 and 12, a first metal protrusion 970 may be set on the third power supply line 9110, a second metal protrusion 9206 may be set on the light-emitting electrode 9201, a third metal protrusion 9803 may be set on one end of the conductive line 9801, and a fourth metal protrusion 9804 may be set on the other end of the conductive line 9801.

[0151] In some embodiments, the first metal protrusion 970 is disposed opposite to the third metal protrusion 9803 , and the second metal protrusion 9206 is disposed opposite to the fourth metal protrusion 9804 .

[0152] The sum of the thicknesses of the first metal protrusion 970 and the third metal protrusion 9803 in the Z-axis direction is equal to the sum of the thicknesses of the laser chip 920 , the second metal protrusion 9206 , and the fourth metal protrusion 9804 in the Z-axis direction.

[0153] In some embodiments, when the adapter plate 980 is placed upside down on top of the laser chip 920, the first metal protrusion 970 is welded to the third metal protrusion 9803, and the second metal protrusion 9206 is welded to the fourth metal protrusion 9804, thereby achieving a power supply connection between the substrate 910 and the laser chip 920 through the adapter plate 980. The bias current transmitted by the power supply line 9104 is then transmitted to the light-emitting electrode 9201 via the conductive wire 9801 on the adapter plate 980, causing the light-emitting area of ​​the laser chip 920 to generate a laser beam.

[0154] 12 , a signal line 9802 is disposed in the fifth avoidance portion 9813 . The signal line 9802 is configured to achieve signal connection between the substrate 910 and the laser chip 920 .

[0155] In some embodiments, signal line 9802 is arranged along the Y-axis and is located on the left side of ground conductive layer 9800 (the negative end of the X-axis shown in FIG12 ). Signal line 9802 is located on the left side of conductive line 9801. A gap is formed between signal line 9802 and ground conductive layer 9800, so that signal line 9802 is not connected to ground conductive layer 9800.

[0156] One end of the signal line 9802 is electrically connected to the high-frequency signal line 9103 on the substrate 910, and the other end is electrically connected to the modulation area of ​​the laser chip 920, thereby realizing the electrical connection between the high-frequency signal line 9103 and the modulation area, and then realizing the signal connection between the substrate 910 and the laser chip 920 through the adapter plate 980.

[0157] The high-frequency signal line 9103 provides a modulation current signal to the modulation area through the signal line 9802 on the adapter board 980 to perform signal modulation on the laser beam.

[0158] Exemplarily, the adapter plate 980 is installed upside down on the top surface of the laser chip 920, and the adapter plate 980 covers part of the high-frequency signal line 9103. The right end of the high-frequency signal line 9103 is set corresponding to the lower end of the signal line 9802, and the modulation electrode 9202 of the laser chip 920 is set corresponding to the upper end of the signal line 9802. In this way, the right end of the high-frequency signal line 9103 is welded to the lower end of the signal line 9802, and the upper end of the signal line 9802 is welded to the modulation electrode 9202, so as to realize the electrical connection between the modulation electrode 9202 and the high-frequency signal line 9103 through the signal line 9802 on the adapter plate 980, thereby providing a modulation current signal to the modulation area through the adapter plate 980, so that the modulation area of ​​the laser chip 920 modulates the laser beam, so that the laser chip 920 generates a modulated light signal.

[0159] Because laser chip 920 is mounted on the top surface of substrate 910, there is a thickness difference between the top surfaces of laser chip 920 and substrate 910. When adapter plate 980 is mounted upside down on top of laser chip 920, a gap exists between the bottom surface of adapter plate 980 and the top surface of substrate 910. To solder signal line 9802 and high-frequency signal line 9103 on adapter plate 980, the gap between high-frequency signal line 9103 and signal line 9802 can be filled with solder.

[0160] In some embodiments, referring to FIG. 10 , a fifth metal protrusion 940, such as a metal pillar, may also be provided at the right end of the high-frequency signal line 9103. The fifth metal protrusion 940 is formed by extending the high-frequency signal line 9103 along the Z-axis. The thickness of the fifth metal protrusion 940 along the Z-axis may be equal to or less than the thickness difference between the top surface of the laser chip 920 and the top surface of the substrate 910.

[0161] 14 , when the adapter plate 980 is mounted upside down on the top surface of the laser chip 920 , one end of the signal line 9802 on the adapter plate 980 is directly welded to the modulation electrode 9202 , and the other end of the signal line 9802 is welded to the fifth metal protrusion 940 , so as to realize the signal connection between the substrate 910 and the laser chip 920 through the adapter plate 980 , thereby transmitting the modulation current signal to the modulation area of ​​the laser chip 920 through the adapter plate 980 .

[0162] Referring to Figure 11, the thickness of the fifth metal protrusion 940 in the Z-axis direction may also be greater than the thickness difference between the top surface of the laser chip 920 and the top surface of the substrate 910. At this time, a sixth metal protrusion 9208 is arranged on the modulation electrode 9202, and the sixth metal protrusion 9208 extends from the modulation electrode 9202 along the Z-axis direction. The thickness of the sixth metal protrusion 9208 in the Z-axis direction is smaller than the thickness of the fifth metal protrusion 940.

[0163] 14 , when the adapter plate 980 is placed upside down on top of the laser chip 920 , one end of the signal line 9802 on the adapter plate 980 is welded to the fifth metal protrusion 940 , and the other end of the signal line 9802 is welded to the sixth metal protrusion 9208 , so as to realize the signal connection between the substrate 910 and the laser chip 920 through the adapter plate 980 , thereby transmitting the modulated current signal to the modulation area of ​​the laser chip 920 through the adapter plate 980 .

[0164] In some embodiments, referring to Figures 10 and 12, a fifth metal protrusion 940 may be set at the right end of the high-frequency signal line 9103, a sixth metal protrusion 9208 may be set on the modulation electrode 9202, a seventh metal protrusion 9805 may be set on one end of the signal line 9802, and an eighth metal protrusion 9808 may be set on the other end of the signal line 9802.

[0165] The fifth metal protrusion 940 is disposed opposite to the seventh metal protrusion 9805 , and the sixth metal protrusion 9208 is disposed opposite to the eighth metal protrusion 9808 .

[0166] The sum of the thicknesses of the fifth metal protrusion 940 and the seventh metal protrusion 9805 in the Z-axis direction is equal to the sum of the thicknesses of the laser chip 920 , the sixth metal protrusion 9208 , and the eighth metal protrusion 9808 in the Z-axis direction.

[0167] In some embodiments, when the adapter plate 980 is placed upside down on top of the laser chip 920, the fifth metal protrusion 940 is welded to the seventh metal protrusion 9805, and the sixth metal protrusion 9208 is welded to the eighth metal protrusion 9808, so as to realize the signal connection between the substrate 910, the laser chip 920 and the adapter plate 980, thereby transmitting the modulation current signal transmitted by the high-frequency signal line 9103 to the modulation electrode 9202 through the signal line 9802 on the adapter plate 980, so that the modulation area of ​​the laser chip 920 modulates the laser beam and the electrical signal.

[0168] In some embodiments, since the third power supply line 9110 on the substrate 910 is located on the upper side of the high-frequency signal line 9103 (the positive direction of the Y-axis shown in Figure 14), the dimension between the third power supply line 9110 and the laser chip 920 is smaller than the distance between the high-frequency signal line 9103 and the laser chip 920. Therefore, the length dimension of the conductive line 9801 in the Y-axis direction is smaller than the length dimension of the signal line 9802 in the Y-axis direction.

[0169] In some embodiments, the adapter plate 980 is installed upside down above the laser chip 920, the third power supply line 9110 on the substrate 910 is welded to the conductive line 9801 on the adapter plate 980, the conductive line 9801 is welded to the light-emitting electrode 9201 of the laser chip 920, the high-frequency signal line 9103 on the substrate 910 is welded to the signal line 9802 on the adapter plate 980, and the signal line 9802 is welded to the modulation electrode 9202 of the laser chip 920, so as to transmit the bias current and modulation current signals to the laser chip 920 through the adapter plate 980, so that the laser chip 920 generates a modulated light signal.

[0170] The substrate 910 and the laser chip 920 are connected via the adapter plate 980 , avoiding wire bonding and thus avoiding impedance mismatch problems caused by wire bonding, thereby improving the high-frequency response bandwidth of the laser chip 920 .

[0171] In some embodiments, when the signal connection between the high-frequency signal line 9103 and the modulation electrode 9202 is realized through the adapter plate 980, in order to realize signal reflux, the laser chip 920 needs to be connected to the ground conductive area 9100 on the substrate 910 through the adapter plate 980 to realize grounding of the laser chip 920.

[0172] Referring to Figures 11, 12, and 14, a ground electrode is also provided on the top surface of the laser chip 920. The ground electrode is welded to a ground conductive layer 9800 on the adapter plate 980. A grounding post is provided on the ground conductive area 9100 on the substrate 910. The ground conductive layer 9800 is welded to the grounding post to achieve a ground connection between the laser chip 920 and the ground conductive area 9100 on the substrate 910 through the adapter plate 980.

[0173] 11 , the ground electrodes on the laser chip 920 include a first ground electrode 9203 and a second ground electrode 9204. The first ground electrode 9203 and the second ground electrode 9204 are located on either side of the modulation electrode 9202. The first ground electrode 9203, the modulation electrode 9202, and the second ground electrode 9204 form a GSG (ground-signal-ground) pattern.

[0174] In some embodiments, the first ground electrode 9203 is located on the left side of the modulation electrode 9202 (the left side as shown in FIG11 ), and a first distance L1 is defined between the first ground electrode 9203 and the modulation electrode 9202. The second ground electrode 9204 is located on the right side of the modulation electrode 9202 (the right side as shown in FIG11 ), and a second distance L2 is defined between the second ground electrode 9204 and the modulation electrode 9202. The first distance L1 is equal to the second distance L2.

[0175] 10 , a first grounding post 950 and a second grounding post 960 are provided on the grounding conductive area 9100 of the substrate 910 to connect the first ground electrode 9203, the second ground electrode 9204, and the grounding conductive area 9100 of the substrate 910. The first grounding post 950 and the second grounding post 960 are located above and below the high-frequency signal line 9103, forming a GSG pattern between the first grounding post 950, the high-frequency signal line 9103, and the second grounding post 960.

[0176] In some embodiments, the first grounding column 950 is located on the second grounding conductive region 9111 , and the second grounding column 960 is located on the third grounding conductive region 9102 .

[0177] 14 , the adapter plate 980 is installed upside down above the laser chip 920, the power supply line 9104 on the substrate 910 is welded to the conductive line 9801 on the adapter plate 980, the conductive line 9801 is welded to the light-emitting electrode 9201 of the laser chip 920, the high-frequency signal line 9103 is welded to the signal line 9802 on the adapter plate 980, the signal line 9802 is welded to the modulation electrode 9202 of the laser chip 920, the first ground electrode 9203 and the second ground electrode 9204 on the laser chip 920 are welded to the grounding conductive layer 9800 on the adapter plate 980, and the grounding conductive layer 9800 is welded to the first grounding column 950 and the second grounding column 960 on the substrate 910 to achieve signal grounding of the laser chip 920.

[0178] In some embodiments, when the thickness of the first grounding column 950 and the second grounding column 960 is less than or equal to the thickness of the laser chip 920 , the first grounding electrode 9203 and the second grounding electrode 9204 can be directly welded to the grounding conductive layer 9800 on the adapter plate 980 , thereby achieving signal grounding of the laser chip 920 .

[0179] Referring to Figure 11 , when the thickness of the first grounding post 950 and the second grounding post 960 is slightly greater than the thickness of the laser chip 920, a third grounding post 9207 is provided on the first ground electrode 9203, and a fourth grounding post 9209 is provided on the second grounding electrode 9204. The thickness of the first grounding post 950 and the second grounding post 960 is equal to the sum of the thicknesses of the laser chip 920, the third grounding post 9207, and the fourth grounding post 9209. The first grounding electrode 9203 is welded to the grounding conductive layer 9800 on the adapter plate 980 via the third grounding post 9207, and the second grounding electrode 9204 is welded to the grounding conductive layer 9800 via the fourth grounding post 9209, thereby achieving signal grounding for the laser chip 920.

[0180] Referring to Figure 12 , when the thickness of the first grounding post 950 and the second grounding post 960 is greater than the thickness of the laser chip 920, a third grounding post 9207 is provided on the first ground electrode 9203, a fourth grounding post 9209 is provided on the second ground electrode 9204, and a fifth grounding post 9809 and a sixth grounding post 9810 are provided on the grounding conductive layer 9800 of the adapter plate 980. The fifth grounding post 9809 is welded to the third grounding post 9207, and the sixth grounding post 9810 is welded to the fourth grounding post 9209, thereby achieving signal grounding for the laser chip 920.

[0181] In some embodiments, a third grounding post 9207 is provided on the first ground electrode 9203, and a fourth grounding post 9209 is provided on the second ground electrode 9204. A fifth grounding post 9809, a sixth grounding post 9810, a seventh grounding post 9806, and an eighth grounding post 9807 are provided on the grounding conductive layer 9800 of the adapter plate 980. The third grounding post 9207 is welded to the fifth grounding post 9809, the fourth grounding post 9209 is welded to the sixth grounding post 9810, the first grounding post 950 is welded to the seventh grounding post 9806, and the second grounding post 960 is welded to the eighth grounding post 9807, thereby achieving signal grounding for the laser chip 920.

[0182] In some embodiments, after the first ground electrode 9203 and the second ground electrode 9204 on the laser chip 920 are connected to the ground conductive area 9100 on the substrate 910 through the adapter plate 980, ground wires are arranged on both sides of the high-frequency signal line, so that the transmission mode of the high-frequency electrical signal is the GSG mode, thereby shortening the isolation between the electrical signal return path and the signal channel.

[0183] In some embodiments, the RC parasitic parameters of laser chip 920 significantly affect its frequency response. For example, the parasitic capacitance of laser chip 920 can result in a low bandwidth. To increase the signal bandwidth of laser chip 920, a matching resistor can be added. This matching resistor is connected in parallel with the modulation region of laser chip 920 to ensure that the output impedance of laser chip 920 is consistent with the characteristic impedance of the matching resistor.

[0184] Referring to Figure 12 , a second resistor 9811 is disposed within the fifth relief portion 9813 of the adapter plate 980. Second resistor 9811 can be positioned along the positive Y-axis from the upper end of signal line 9802. One end of second resistor 9811 is connected to signal line 9802, and the other end of second resistor 9811 is connected to grounded conductive layer 9800, grounding the other end of second resistor 9811. This connects second resistor 9811 in parallel with laser chip 920. Second resistor 9811 provides impedance matching, ultimately ensuring that the impedance output by laser chip 920 matches the characteristic impedance of the matching resistor.

[0185] In some embodiments, the second resistor 9811 may be arranged obliquely on the adapter plate 980 or along the X-axis direction on the adapter plate 980. As long as one end of the second resistor 9811 is connected to the signal line 9802 and the other end of the second resistor 9811 is connected to the ground conductive layer 9800, it falls within the scope of protection of the embodiments of the present disclosure.

[0186] In some embodiments, since the space of the adapter board 980 is relatively small, the second resistor 9811 is a thin film resistor that is sintered through an area of ​​the adapter board 980 .

[0187] In some embodiments, the layout of the power supply line 9104 on the substrate 910 is not limited to the layout described in the above embodiment. It is sufficient as long as the right end of the power supply line 9104 is welded to the conductive line 9801 on the adapter plate 980, and the conductive line 9801 is welded to the light-emitting electrode 9201.

[0188] Figure 15 is a second perspective view of the assembly of a substrate, laser chip, and adapter plate in an optical module according to some embodiments of the present disclosure. As shown in Figure 15 , the ground conductive region 9100 on the substrate 910 includes a first ground conductive region 9101 , a second ground conductive region 9111 , and a third ground conductive region 9102 .

[0189] In some embodiments, the first ground conductive region 9101, the second ground conductive region 9111, and the third ground conductive region 9102 are arranged along the Y-axis. The laser chip 920 is mounted on the second ground conductive region 9111. In some embodiments, the X-axis shown in FIG. 15 is the left-right direction, and the Y-axis is the up-down direction.

[0190] In some embodiments, the power supply lines 9104 on the substrate 910 include a first power supply line 9108, a second power supply line 9109, and a third power supply line 9110. The first power supply line 9108 extends from the left side of the substrate 910 in the positive direction of the X-axis. The second power supply line 9109 extends from the right end of the first power supply line 9108 in the positive direction of the Y-axis. The third power supply line 9110 extends from the upper end of the second power supply line 9109 in the positive direction of the X-axis. The first power supply line 9108 and the second power supply line 9109 are located to the left of the laser chip 920, while the third power supply line 9110 is located above the laser chip 920. The first power supply line 9108, the second power supply line 9109, and the third power supply line 9110 form a Z-shaped power supply line.

[0191] The adapter plate 980 is flipped onto the laser chip 920, with its upper end (the positive end on the Y axis as shown in Figure 15) protruding from the laser chip 920. The adapter plate 980 covers the third power supply line 9110, which is provided with a first metal protrusion 970. The light-emitting electrode 9201 is provided with a second metal protrusion 9206. A conductive wire 9801 is provided on the adapter plate 980, with a third metal protrusion 9803 provided at its upper end and a fourth metal protrusion 9804 provided at its lower end. The first metal protrusion 970 is welded to the third metal protrusion 9803, and the second metal protrusion 9206 is welded to the fourth metal protrusion 9804. This connects the power supply between the substrate 910 and the light-emitting area of ​​the laser chip 920 through the adapter plate 980, enabling the light-emitting area to generate a laser beam.

[0192] FIG16 is a second partial connection diagram of a circuit board and a laser chip in an optical module according to some embodiments of the present disclosure. As shown in FIG16 , a substrate 910 is disposed on a ceramic carrier 930. A laser chip 920 is disposed on a grounded conductive region 9100 of the substrate 910. An adapter plate 980 is mounted on the laser chip 920, and one end of a power supply line 9104 is soldered to a conductive line 9801 on the adapter plate 980, which is then soldered to a light-emitting electrode 9201 of the laser chip 920. The other end of the power supply line 9104 is bonded to an electrical pad 305 on the circuit board 300. This allows bias current from the circuit board 300 to be transmitted via the power supply line 9104 and the conductive line 9801 to the light-emitting electrode 9201, thereby providing a bias current to the light-emitting region of the laser chip 920, causing the light-emitting region to generate a laser beam.

[0193] In some embodiments, one end of the high-frequency signal line 9103 is welded to the signal line 9802 on the adapter board 980, and the signal line 9802 is welded to the modulation electrode 9202 of the laser chip 920; the other end of the high-frequency signal line 9103 is wire-connected to the first differential signal line 302 on the circuit board 300, so that the current signal transmitted by the first differential signal line 302 is transmitted to the modulation electrode 9202 via the high-frequency signal line 9103 and the signal line 9802, so as to provide a modulation current signal to the modulation area of ​​the laser chip 920, so that the modulation area modulates the laser beam to obtain a modulated light signal.

[0194] In some embodiments, the first ground electrode 9203 and the second ground electrode 9204 on the laser chip 920 are respectively electrically connected to the ground conductive layer 9800 on the adapter plate 980. The ground conductive layer 9800 is soldered to the ground conductive area 9100 on the substrate 910. The ground conductive area 9100 is respectively electrically connected to the first ground pad 305 and the second ground pad 306 on the circuit board 300 to achieve signal grounding of the laser chip 920.

[0195] In some embodiments, the second differential signal line 303 on the circuit board 300 is wire-bonded to the resistor pad 9106 on the substrate 910 , the resistor pad 9106 is connected to the first resistor 9107 , and the first resistor 9107 is connected to the ground conductive area 9100 to achieve impedance matching of the laser chip 920 .

[0196] The optical module provided by the disclosed embodiment includes an adapter plate within the optical emitting component 400, wherein a substrate is mounted on a ceramic carrier. The substrate is connected to a circuit board via bonding wires, a laser chip is mounted on the substrate, and the adapter plate is flip-chip mounted on the laser chip. The adapter plate electrically connects the laser chip to the substrate, replacing the bonding wires currently used to connect the laser chip to the substrate. This avoids impedance mismatch issues caused by bonding wires. Ground electrodes are provided on both sides of the modulation electrode on the laser chip, so that the modulated electrical signal and the GND form a GSG pattern. The modulation electrode and the ground electrode are located on the same plane, thereby shortening the return path of the modulated electrical signal and the isolation between the signal channels, thereby effectively increasing the signal bandwidth.

[0197] After the laser chip 920, adapter plate 980, substrate 910 and circuit board 300 are electrically connected, the light-emitting area in the laser chip 920 generates a laser beam under the action of the bias current. The laser beam is transmitted to the modulation area through the optical waveguide layer in the laser chip 920. The modulation area modulates the laser beam according to the modulation current signal to obtain a modulated light signal, and the modulated light signal is emitted through the optical waveguide layer.

[0198] With the rapid development of application markets such as big data, cloud computing, and artificial intelligence, the demand for data communication optical modules is also increasing rapidly. The optical device industry continues to evolve towards higher speeds, lower power consumption, and lower costs. Semiconductor laser chips, as key components in optical communications, face higher challenges. The demand for laser chips is gradually shifting from 10G to 56G and 100G.

[0199] Figure 17 is a second structural diagram of a laser chip in an optical module according to some embodiments of the present disclosure. As shown in Figure 17, the EML laser chip includes a distributed feedback laser (DFB) light source 9210, an electroabsorption modulator (EAM) 9211, and a first optical waveguide 9212 connecting the DFB light source 9210 and the EAM modulator 9211. The DFB light source 9210 is the light-emitting section, and the EAM modulator 9211 is the modulation section.

[0200] The DFB light source 9210 generates a laser beam under the action of the bias current. The laser beam is transmitted to the EAM modulator 9211 through the first optical waveguide 9212. The EAM modulator 9211 receives a modulation current signal from the circuit board 300 through the modulation electrode 9202. The EAM modulator 9211 modulates the laser beam according to the current signal to obtain modulated light, which is then emitted through the first optical waveguide 9212.

[0201] The DFB light source 9210 and the EAM modulator 9211 can be designed independently. The light source part can improve the photoelectric conversion efficiency and output power of the laser chip by reducing the number of QWs and increasing the gain area. The modulator part avoids the interaction between photons and electrons in the laser chip during high-speed modulation due to the absence of a resonant light field, and can achieve a modulation rate of 100Gbuad and above.

[0202] In order to meet the demand for higher-speed operation, it is necessary to reduce the capacitance of the EAM to increase the modulation rate. Reducing the capacitance to increase the modulation rate can be achieved by reducing the cavity length, ridge width, and increasing the thickness of the active layer. However, this solution will lead to a deterioration of the far-field performance. For example, reducing the cavity length and ridge width will cause the optical confinement factor of the quantum well (QW) to decrease, resulting in the near-field spot of the laser chip emitting light being too small and the far-field divergence angle of the emitted light being too small.

[0203] Figure 18a is a structural diagram of a deeply etched waveguide in an optical module provided according to some embodiments of the present disclosure. Figure 18b is a schematic diagram of a mode spot of an optical waveguide in an optical module provided according to some embodiments of the present disclosure. Figure 18c is a graph of the lateral divergence angle of a laser chip in an optical module provided according to some embodiments of the present disclosure. Figure 18d is a graph of the longitudinal divergence angle of a laser chip in an optical module provided according to some embodiments of the present disclosure. As shown in Figures 18a-18d, in laser chips with higher modulation rates (such as 100Gb / s and above), the first optical waveguide 9212 often uses a deeply etched waveguide. Deeply etched waveguides increase the lateral confinement of the waveguide structure on the light field. Deeply etched waveguides are combined with a reduced ridge width to further reduce the lateral size of the mode spot in the optical waveguide, thereby reducing the near-field mode spot of the light. Under the action of diffraction, the smaller the near-field mode spot, the larger the far-field divergence angle.

[0204] 18 c and 18 d , when the width of the deeply etched optical waveguide is typically 1.2 μm, the far-field divergence angle of the laser chip 920 is 30°×46°.

[0205] The optical coupling of laser chip 920 to an optical fiber often involves first focusing the light into the fiber through a lens. Excessively large far-field divergence angles of the EML laser chip, or a significant difference between the horizontal and vertical divergence angles, can reduce the coupling efficiency between the laser chip and the optical fiber. For example, if the far-field divergence angle of laser chip 920 is too large, part of the light field emitted by the laser chip will exceed the range of the lens. The difference in horizontal and vertical divergence angles can introduce astigmatism into the optical path, causing the focal lengths of light in the two directions to be located in different planes after passing through the lens, thereby reducing the fiber coupling efficiency. Therefore, improving the near-field spot shape and far-field divergence angle of the EML laser chip is crucial for its application.

[0206] To increase the modulation rate of the EML laser chip, the first optical waveguide 9212 connecting the DFB light source 9210 and the EAM modulator 9211 is constructed using a deep-etched waveguide. The number of QWs is increased to maintain the modulation rate, but this sacrifices the far-field divergence angle. Compared to deep-etched waveguides, the effective refractive index difference between the core and the cladding layers of a buried heterojunction (BH) waveguide is smaller, resulting in less confinement of the light field. Consequently, the near-field mode spot of light transmitted by the BH waveguide is larger, resulting in a correspondingly smaller far-field divergence angle.

[0207] Figure 19 is a third structural diagram of a laser chip in an optical module according to some embodiments of the present disclosure, and Figure 20 is a partial top view of a laser chip in an optical module according to some embodiments of the present disclosure. As shown in Figures 19 and 20, to improve the far-field divergence angle of the EML laser chip, the optical waveguide of laser chip 920 includes a first optical waveguide 9212 and a second optical waveguide 9214.

[0208] In some embodiments, the first optical waveguide 9212 connects the DFB light source 9210 and the EAM modulator 9211 .

[0209] The light input end of the second optical waveguide 9214 is coupled to the light output end of the first optical waveguide 9212 .

[0210] In some embodiments, the first optical waveguide 9212 is a deep-etched optical waveguide to increase the modulation rate of the laser chip.

[0211] The second optical waveguide 9214 is a buried heterojunction optical waveguide, which connects to the light output by the first optical waveguide 9212 to optimize the far-field divergence angle.

[0212] The modulated light output from the deeply etched optical waveguide is transmitted to the buried heterojunction optical waveguide. Since the effective refractive index difference between the waveguide core and the cladding in the buried heterojunction optical waveguide is small, the buried heterojunction optical waveguide has little limiting effect on the light field, resulting in a larger near-field mode spot and a correspondingly smaller far-field divergence angle. Therefore, the buried heterojunction optical waveguide is docked at the light output end of the deeply etched optical waveguide to optimize the far-field divergence angle.

[0213] When the deeply etched optical waveguide and the buried heterojunction optical waveguide are directly end-face coupled, due to the mode field mismatch between the deeply etched optical waveguide and the buried heterojunction optical waveguide, the effective refractive index difference of the deeply etched optical waveguide is different from the effective refractive index difference of the buried heterojunction optical waveguide: the effective refractive index difference of the deeply etched optical waveguide is larger, and the effective refractive index difference of the buried heterojunction optical waveguide is smaller, which easily causes light to be reflected at the coupling end face of the deeply etched optical waveguide and the buried heterojunction optical waveguide, affecting the transmittance of light and thus affecting the light coupling efficiency.

[0214] In some embodiments, to avoid light reflection at the coupling end facets of the deep-etched optical waveguide and the buried heterojunction optical waveguide, the optical waveguide of the laser chip 920 includes a third optical waveguide 9213, which is a transition optical waveguide. The third optical waveguide 9213 is disposed between the first optical waveguide 9212 and the second optical waveguide 9214.

[0215] The light input end of the third optical waveguide 9213 matches the mode field of the light output end of the first optical waveguide 9212 , and the light input end of the third optical waveguide 9213 is coupled to the light output end of the first optical waveguide 9212 .

[0216] The mode fields of the light output end of the third optical waveguide 9213 and the light input end of the second optical waveguide 9214 are matched, and the light output end of the third optical waveguide 9213 and the light input end of the second optical waveguide 9214 are coupled and connected.

[0217] The third optical waveguide 9213 provides a transitional connection between the first optical waveguide 9212 and the second optical waveguide 9214, achieving a transitional change in the mode field, thereby matching the mode fields between the first optical waveguide 9212 and the second optical waveguide 9214 and improving the optical coupling efficiency. The third optical waveguide 9213 also improves the light transmittance between the first optical waveguide 9212 and the second optical waveguide 9214.

[0218] Figure 21 is a top view of a partial structure of a laser chip in an optical module according to some embodiments of the present disclosure. Figure 22 is a diagram of the waveguide structure of a laser chip in an optical module according to some embodiments of the present disclosure. Figure 23a is a cross-sectional view taken at point AA in Figure 21. As shown in Figures 21, 22, and 23a, the first optical waveguide 9212 is a deeply etched optical waveguide to increase the modulation rate of the laser chip.

[0219] In some embodiments, the first optical waveguide 9212 includes a first waveguide core layer 9221 , a first cladding layer 9222 , and a second cladding layer 9223 .

[0220] The first cladding 9222 is arranged on the substrate layer 9220 of the laser chip 920 along the epitaxial growth direction, the first waveguide core layer 9221 is arranged on the first cladding 9222 along the epitaxial growth direction, and the second cladding 9223 is arranged on the first waveguide core layer 9221 along the epitaxial growth direction to surround the first waveguide core layer 9221 through the first cladding 9222 and the second cladding 9223.

[0221] In some embodiments, the substrate layer 9220 may be an N-type InP substrate layer, the first cladding layer 9222 may be a P-type InP layer, the second cladding layer 9223 may be a P-type InP layer, and the first waveguide core layer 9221 may be an InGaAsP core layer.

[0222] In some embodiments, the effective refractive index of the first waveguide core layer 9221 is greater than the effective refractive index of the first cladding layer 9222, the effective refractive index of the first cladding layer 9222 may be the same as the effective refractive index of the second cladding layer 9223, and there is a first effective refractive index difference between the effective refractive index of the first waveguide core layer 9221 and the effective refractive indices of the first cladding layer 9222 and the second cladding layer 9223. The signal light transmitted by the first waveguide core layer 9221 is reflected at the first cladding layer 9222 and the second cladding layer 9223 to constrain and limit the light field transmitted by the first waveguide core layer 9221.

[0223] In order to transmit the modulated light output by the EAM modulator 9211, the first waveguide core layer 9221 of the first optical waveguide 9212 has a first width W1 and a first thickness H1. In this way, the modulated light output by the EAM modulator 9211 is transmitted within the first waveguide core layer 9221, and the modulated light is reflected at the first cladding layer 9222 and the second cladding layer 9223 to improve the transmittance of the light.

[0224] In some embodiments, the first width W1 is 1-2 μm, and the first thickness H1 is 150-300 nm.

[0225] In some embodiments, the first width W1 is 2 μm, and the first thickness H1 is 300 nm.

[0226] In some embodiments, the width of the first cladding layer 9222 may be equal to the width of the second cladding layer 9223, and the width of the first cladding layer 9222 may be equal to the width of the first waveguide core layer 9221. The thickness of the first cladding layer 9222 may be equal to the thickness of the second cladding layer 9223, and the thickness of the first cladding layer 9222 may be greater than the thickness of the first waveguide core layer 9221. In some embodiments, the thickness of the first cladding layer 9222 may be 1.5 to 2 μm.

[0227] In some embodiments, since the first optical waveguide 9212 is coupled to the EAM modulator 9211, the EAM modulator 9211 includes a substrate layer, an active layer, a waveguide layer, an electrode layer, etc., and buried layers are provided on both sides of the active layer to block electrons on both sides of the active layer through the buried layers.

[0228] In some embodiments, the first waveguide core layer 9221 of the first optical waveguide 9212 is coupled to the active layer of the EAM modulator 9211. To transmit light from the active layer to the first waveguide core layer 9221, the material of the first waveguide core layer 9221 is different from the material of the active layer of the EAM modulator 9211, such that the effective refractive index of the first waveguide core layer 9221 is greater than the effective refractive index of the active layer.

[0229] In some embodiments, the material of the first waveguide core layer 9221 is InGaAsP, and the material of the active layer of the EAM modulator 9211 is an Al-containing material, for example, InAlGaAs.

[0230] In some embodiments, since buried regions are provided on both sides of the active layer in the EAM modulator 9211 , the first waveguide core layer 9221 is coupled to the active layer. Thus, a first buried region 9224 and a second buried region 9225 may also be provided on both sides of the first waveguide core layer 9221 .

[0231] In some embodiments, the first buried region 9224 and the second buried region 9225 are located on both sides of the first waveguide core layer 9221. The first buried region 9224 and the second buried region 9225 surround the first waveguide core layer 9221 to protect the first waveguide core layer 9221. In some embodiments, the first buried region 9224 and the second buried region 9225 are SiO2.

[0232] In some embodiments, the first buried region 9224 and the second buried region 9225 are disposed on the substrate layer 9220 along the epitaxial growth direction, and the top surfaces of the first buried region 9224 and the second buried region 9225 may be flush with the top surface of the second cladding layer 9223 .

[0233] Figure 23b is a cross-sectional view taken at CC in Figure 21. As shown in Figures 22 and 23b, the second optical waveguide 9214 includes a second waveguide core layer 9226, a first cladding layer 9222, and a second cladding layer 9223. The second optical waveguide 9214 is a buried heterojunction optical waveguide to optimize the far-field divergence angle.

[0234] The first cladding 9222 is arranged on the substrate layer 9220 along the epitaxial growth direction, the second waveguide core layer 9226 is arranged on the first cladding 9222 along the epitaxial growth direction, and the second cladding 9223 is arranged on the second waveguide core layer 9226 along the epitaxial growth direction to surround the second waveguide core layer 9226 through the first cladding 9222 and the second cladding 9223.

[0235] In some embodiments, the substrate layer 9220 may be an N-type InP substrate layer, the first cladding layer 9222 may be a P-type InP layer, the second cladding layer 9223 may be a P-type InP layer, and the second waveguide core layer 9226 may be an InGaAsP core layer.

[0236] In some embodiments, the first cladding of the second optical waveguide 9214 and the first cladding of the first optical waveguide 9212 may be the same cladding, and the second cladding of the second optical waveguide 9214 and the second cladding of the first optical waveguide 9212 may be the same cladding.

[0237] In some embodiments, the effective refractive index of the second waveguide core layer 9226 is less than the effective refractive index of the first waveguide core layer 9221, the effective refractive index of the second waveguide core layer 9226 is greater than the effective refractive index of the first cladding layer 9222, the effective refractive index of the first cladding layer 9222 may be the same as the effective refractive index of the second cladding layer 9223, and there is a second effective refractive index difference between the effective refractive index of the second waveguide core layer 9226 and the effective refractive indices of the first cladding layer 9222 and the second cladding layer 9223, so that the first cladding layer 9222 and the second cladding layer 9223 confine and limit the light field transmitted by the second waveguide core layer 9226.

[0238] Because the effective refractive index of the second waveguide core layer 9226 is smaller than the effective refractive index of the first waveguide core layer 9221, the second effective refractive index difference of the second optical waveguide 9214 is smaller than the first effective refractive index difference of the first optical waveguide 9212. Therefore, compared with the first optical waveguide 9212, the second optical waveguide 9214 has a smaller restrictive effect on the light field it transmits, and the near-field mode spot of the light output by the second optical waveguide 9214 is larger, and the corresponding far-field divergence angle is smaller, thereby optimizing the near-field light spot shape and the far-field divergence angle through the second optical waveguide 9214.

[0239] In some embodiments, the second waveguide core layer 9226 is made of the same material as the first waveguide core layer 9221. Since the effective refractive index of the waveguide core layer is positively correlated with the width of the waveguide core layer, in order to reduce the effective refractive index of the second waveguide core layer 9226, the width of the second waveguide core layer 9226 can be reduced compared to the first waveguide core layer 9221.

[0240] In some embodiments, the second waveguide core layer 9226 has a second width W2, and the second width W2 is smaller than the first width W1, thereby reducing the effective refractive index of the second waveguide core layer 9226, so that the second effective refractive index difference of the second optical waveguide 9214 is smaller than the first effective refractive index difference of the first optical waveguide 9212, thereby reducing the far-field divergence angle of the light field transmitted by the second optical waveguide 9214.

[0241] In some embodiments, as the thickness of the core layer of the optical waveguide decreases, the optical waveguide has less restriction on the light field, and the near-field light spot increases. Thus, the second waveguide core layer 9226 has a second thickness H2, and the second thickness H2 is less than the first thickness H1, so as to reduce the overall size of the second waveguide core layer 9226, thereby reducing the restriction of the second waveguide core layer 9226 and the light field, thereby reducing the far-field divergence angle of the light field transmitted by the second optical waveguide 9214.

[0242] In some embodiments, the second width W2 is 0.5-2 nm, and the second thickness H2 is 150-300 nm.

[0243] In some embodiments, the second width W2 has a size of 2 nm, and the second thickness H2 has a size of 150 nm.

[0244] Because the width W1 of the first waveguide core layer 9221 is greater than the width W2 of the second waveguide core layer 9226, the cross-sectional dimensions of the first optical waveguide 9212 and the second optical waveguide 9214 differ. When the signal light is coupled between the first optical waveguide 9212, the third optical waveguide 9213, and the second optical waveguide 9214, the different cross-sectional dimensions of the optical waveguides cause a sudden change in the light transmission mode, thereby causing loss. Therefore, the third optical waveguide 9213 is configured as a tapered optical waveguide to achieve a transition in the cross-sectional dimensions of the first optical waveguide 9212 and the second optical waveguide 9214.

[0245] 22 , along the light emission direction, the third optical waveguide 9213 is provided between the first optical waveguide 9212 and the second optical waveguide 9214. The third optical waveguide 9213 has a length L.

[0246] In some embodiments, the third optical waveguide 9213 includes a first tapered optical waveguide 9215 and a second tapered optical waveguide 9216 .

[0247] The light input end of the first tapered optical waveguide 9215 is coupled to the light output end of the first optical waveguide 9212 .

[0248] The light output end of the first tapered optical waveguide 9215 is coupled to the light input end of the second tapered optical waveguide 9216 .

[0249] The light output end of the second tapered optical waveguide 9216 is coupled to the light input end of the second optical waveguide 9214 .

[0250] In some embodiments, the mode fields of the first optical waveguide 9212, the first tapered optical waveguide 9215, the second tapered optical waveguide 9216, and the second optical waveguide 9214 are matched to ensure that the signal light transmitted by the first optical waveguide 9212 is smoothly transmitted to the second optical waveguide 9214 through the first tapered optical waveguide 9215 and the second tapered optical waveguide 9216, and the transmittance of the light is guaranteed.

[0251] In some embodiments, the width of the light-entering end of the first tapered optical waveguide 9215 may be equal to the width of the first optical waveguide 9212 .

[0252] In some embodiments, the width of the first tapered optical waveguide 9215 gradually increases along the light emission direction, so that the width of the end of the first tapered optical waveguide 9215 is greater than the width of the first optical waveguide 9212. In this way, the effective refractive index of the waveguide core layer of the first tapered optical waveguide 9215 is greater than the effective refractive index of the first waveguide core layer 9221, so as to facilitate the coupling of the signal light transmitted by the first optical waveguide 9212 to the third optical waveguide 9213.

[0253] In some embodiments, the width of the second tapered optical waveguide 9216 gradually decreases along the light emission direction, and the width of the light output end of the second tapered optical waveguide 9216 can be equal to the width of the second optical waveguide 9214. In this way, the effective refractive index of the second tapered optical waveguide 9216 is greater than the effective refractive index of the second waveguide core layer 9226, and the limiting effect of the second waveguide core layer 9226 on the light field is less than the limiting effect of the second tapered optical waveguide 9216 on the light field, so that the signal light transmitted by the first tapered optical waveguide 9215 is slowly transmitted to the second optical waveguide 9214 via the second tapered optical waveguide 9216, avoiding light reflection and loss.

[0254] FIG23 c is a cross-sectional view at CC in FIG21 . As shown in FIG23 c , the first tapered optical waveguide 9215 and the second tapered optical waveguide 9216 have the same structure. The second tapered optical waveguide 9216 includes a third waveguide core layer 9227 , a first cladding layer 9222 , and a second cladding layer 9223 .

[0255] In some embodiments, the first cladding 9222 is arranged on the substrate layer 9220 along the epitaxial growth direction, the third waveguide core layer 9227 is arranged on the first cladding 9222 along the epitaxial growth direction, and the second cladding 9223 is arranged on the third waveguide core layer 9227 along the epitaxial growth direction, so as to surround the third waveguide core layer 9227 by the first cladding 9222 and the second cladding 9223.

[0256] In some embodiments, the substrate layer 9220 may be an N-type InP substrate layer, the first cladding layer 9222 may be a P-type InP layer, the second cladding layer 9223 may be a P-type InP layer, and the third waveguide core layer 9227 may be an InGaAsP core layer.

[0257] In some embodiments, the first cladding of the third optical waveguide 9213 and the first cladding of the first optical waveguide 9212 may be the same cladding, and the second cladding of the third optical waveguide 9213 and the second cladding of the first optical waveguide 9212 may be the same cladding.

[0258] The effective refractive index of the third waveguide core layer 9227 may be smaller than the effective refractive index of the first waveguide core layer 9221, the effective refractive index of the third waveguide core layer 9227 may be greater than the effective refractive index of the first cladding layer 9222, the effective refractive index of the first cladding layer 9222 may be the same as the effective refractive index of the second cladding layer 9223, and there is a third effective refractive index difference between the effective refractive index of the third waveguide core layer 9227 and the effective refractive indices of the first cladding layer 9222 and the second cladding layer 9223, so that the first cladding layer 9222 and the second cladding layer 9223 constrain and limit the light field transmitted by the third waveguide core layer 9227.

[0259] The third effective refractive index difference of the third optical waveguide 9213 is smaller than the first effective refractive index difference of the first optical waveguide 9212, and the second effective refractive index difference of the second optical waveguide 9214 is smaller than the third effective refractive index difference of the third optical waveguide 9213. In this way, when light is transmitted along the first optical waveguide 9212, the third optical waveguide 9213, and the second optical waveguide 9214, the restriction effect on the light field gradually decreases, so that light does not cause reflection and loss when it is transmitted through the third optical waveguide 9213.

[0260] 23c , in order to achieve a transition connection between the first optical waveguide 9212 and the second optical waveguide 9214 through the third optical waveguide 9213, the third waveguide core layer 9227 has a third width W3 and a third thickness H3. The third width W3 may be greater than the first width W1 of the first waveguide core layer 9221, and the third thickness H3 may be equal to the first thickness H1 of the first waveguide core layer 9221. The third width W3 may be greater than the second width W2 of the second waveguide core layer 9226, and the third thickness H3 may be greater than the second thickness H2 of the second waveguide core layer 9226.

[0261] In some embodiments, the third width W3 is 1.1-2.5 μm, and the third thickness H3 is 150-300 nm.

[0262] In some embodiments, the third width W3 has a size of 2.5 μm, and the third thickness H3 has a size of 300 μm.

[0263] 21 , to achieve a smooth transition from the first optical waveguide 9212 to the second optical waveguide 9214, a third optical waveguide 9213 is formed on the laser chip 920. When preparing the third optical waveguide 9213, photolithography is first performed along the first photolithography lines, and the mesa structure of the second optical waveguide 9214 is etched. The top layer is then epitaxially grown to facilitate coupling of the light output end of the third optical waveguide 9213 with the second optical waveguide 9214. Then, photolithography is performed along the second photolithography lines, and the ridge structure of the first optical waveguide 9212 is etched to facilitate coupling of the light input end of the third optical waveguide 9213 with the light output end of the first optical waveguide 9212.

[0264] In some embodiments, when preparing the laser chip 920, after growing an active layer, a waveguide layer, an electrode layer, a buried layer and other structures on the substrate layer, photolithography is performed to obtain a first optical waveguide (deeply etched optical waveguide) 9212 and a second optical waveguide (buried heterojunction optical waveguide) 9214, and then the first optical waveguide 9212 and the second optical waveguide 9214 are etched along the first photolithography line and the second photolithography line to obtain a third optical waveguide 9213, so as to achieve a smooth transition from the deeply etched optical waveguide (first optical waveguide 9212) to the shallowly etched optical waveguide (second optical waveguide 9214) through the third optical waveguide 9213, and light will not cause reflection and loss when transmitted in the third optical waveguide 9213.

[0265] Because the third optical waveguide 9213 is formed through two photolithography processes, there may be an alignment misalignment among the first optical waveguide 9212 , the third optical waveguide 9213 , and the second optical waveguide 9214 . This misalignment may cause a difference in the transmittance of light transmitted by the first optical waveguide 9212 , the third optical waveguide 9213 , and the second optical waveguide 9214 , thereby affecting the light coupling efficiency.

[0266] Figure 24a is a transmittance relationship diagram (1) of a transition optical waveguide in an optical module according to some embodiments of the present disclosure, Figure 24b is a transmittance relationship diagram (2) of a transition optical waveguide in an optical module according to some embodiments of the present disclosure, and Figure 24c is a transmittance relationship diagram (3) of a transition optical waveguide in an optical module according to some embodiments of the present disclosure. As shown in Figures 24a, 24b, and 24c, a first optical waveguide 9212, a third optical waveguide 9213, and a second optical waveguide 9214 are sequentially arranged on a laser chip 920 along the light emission direction.

[0267] In some embodiments, the first optical waveguide 9212 is coupled to the DFB light source 9210 of the laser chip 920, and the first optical waveguide 9212 is coupled to the EAM modulator 9211 of the laser chip 920. The light beam generated by the DFB light source 9210 is transmitted to the EAM modulator 9211 via the first optical waveguide 9212. After the EAM modulator 9211 modulates the light beam to obtain modulated light, the modulated light is coupled to the third optical waveguide 9213 via the first optical waveguide 9212. The third optical waveguide 9213 couples the modulated light to the second optical waveguide 9214.

[0268] 24a , when a smooth transition from the first optical waveguide 9212 to the second optical waveguide 9214 is achieved through the third optical waveguide 9213 without causing reflection and loss, it is detected that as the length L of the third optical waveguide 9213 increases, the optical coupling transmittance of the first optical waveguide 9212 and the second optical waveguide 9214 via the third optical waveguide 9213 gradually increases. Then, when the optical transmittance of the third optical waveguide 9213 reaches a certain node, the optical transmittance of the third optical waveguide 9213 no longer increases with the increase of the length L. Therefore, the optical transmittance can be optimized by adjusting the length L of the third optical waveguide 9213.

[0269] In some embodiments, the length L of the third optical waveguide 9213 is 30-150 μm to improve light transmittance among the first optical waveguide 9212 , the third optical waveguide 9213 , and the second optical waveguide 9214 .

[0270] In some embodiments, the length L of the third optical waveguide 9213 is 50-100 μm to optimize light transmittance among the first optical waveguide 9212 , the third optical waveguide 9213 , and the second optical waveguide 9214 .

[0271] In some embodiments, the length L of the third optical waveguide 9213 is 100 μm to ensure light transmittance among the first optical waveguide 9212 , the third optical waveguide 9213 , and the second optical waveguide 9214 .

[0272] In some embodiments, since the third optical waveguide 9213 includes a first tapered optical waveguide 9215 and a second tapered optical waveguide 9216, along the light emission direction, the width of the first tapered optical waveguide 9215 gradually increases, and the width of the second tapered optical waveguide 9216 gradually decreases. In order to optimize the light transmittance of the third optical waveguide 9213, the length ratio of the first tapered optical waveguide 9215 and the second tapered optical waveguide 9216 is not restricted, as long as the length of the third optical waveguide 9213 satisfies 50 to 100 μm.

[0273] 24b , when a smooth transition from the first optical waveguide 9212 to the second optical waveguide 9214 is achieved through the third optical waveguide 9213 without causing reflection and loss, it is detected that as the widths of the first optical waveguide 9212, the third optical waveguide 9213, and the second optical waveguide 9214 increase, the optical coupling transmittance of the first optical waveguide 9212 through the third optical waveguide 9213 and the second optical waveguide 9214 gradually increases. Then, when the optical transmittance of the third optical waveguide 9213 reaches a certain node, the optical transmittance of the third optical waveguide 9213 no longer increases with the increase in the width of the optical waveguide. Therefore, the optical transmittance can be optimized by adjusting the widths of the first optical waveguide 9212, the third optical waveguide 9213, and the second optical waveguide 9214.

[0274] In some embodiments, the first width W1 of the first waveguide core layer 9221 in the first optical waveguide 9212 needs to meet the requirements of 1 to 2 μm, the second width W2 of the second waveguide core layer 9226 in the second optical waveguide 9214 needs to meet the requirements of 0.5 to 2 nm, and the third width W3 of the third waveguide core layer 9227 in the third optical waveguide 9213 needs to meet the requirements of 1.1 to 2.5 μm, so as to optimize the light transmittance among the first optical waveguide 9212, the third optical waveguide 9213 and the second optical waveguide 9214.

[0275] In some embodiments, the first width W1 has a size of 2 μm, the second width W2 has a size of 2 nm, and the third width W3 has a size of 2.5 μm.

[0276] 24 c , the optical waveguide on the laser chip 920 is subjected to two photolithography steps to obtain a third optical waveguide 9213. The alignment deviation between the first optical waveguide 9212, the third optical waveguide 9213, and the second optical waveguide 9214 is negatively correlated with the light transmittance. To optimize the light transmittance, the width of the first optical waveguide 9212 is set to 2 μm, the width of the second optical waveguide 9214 is set to 2 nm, the maximum width of the third optical waveguide 9213 is set to 2.5 μm, and the length of the third optical waveguide 9213 is set to 100 μm. This optimizes the alignment deviation between the first optical waveguide 9212, the third optical waveguide 9213, and the second optical waveguide 9214, thereby optimizing the light transmittance.

[0277] Figure 25a is a simulation result (Figure 1) of the overall far-field morphology of a laser chip in an optical module according to some embodiments of the present disclosure. Figure 25b is a simulation result (Figure 2) of the overall far-field morphology of a laser chip in an optical module according to some embodiments of the present disclosure. Figure 25c is a curve (Figure 2) of the lateral divergence angle of a laser chip in an optical module according to some embodiments of the present disclosure. Figure 25d is a curve (Figure 2) of the longitudinal divergence angle of a laser chip in an optical module according to some embodiments of the present disclosure. As shown in Figures 25a-25d, a third optical waveguide 9213 and a second optical waveguide 9214 are added to the output end of the first optical waveguide 9212 in the laser chip 920 in sequence.

[0278] In some embodiments, the second optical waveguide 9214 is coupled to the first optical waveguide 9212 through the third optical waveguide 9213. The third optical waveguide 9213 enables a smooth transition between the first optical waveguide 9212 and the second optical waveguide 9214 without causing light reflection and loss, thereby achieving a coupled connection between the first optical waveguide 9212 and the second optical waveguide 9214, reducing end face reflection of light, and improving light coupling efficiency.

[0279] In some embodiments, because the first optical waveguide 9212 is a deep-etched optical waveguide and the second optical waveguide 9214 is a buried heterojunction optical waveguide, the width of the second waveguide core layer 9226 of the second optical waveguide 9214 is smaller than the width of the first waveguide core layer 9221 of the first optical waveguide 9212, and the thickness of the second waveguide core layer 9226 is smaller than the thickness of the first waveguide core layer 9221. Compared with the first optical waveguide 9212, the effective refractive index difference between the waveguide core layer of the second optical waveguide 9214 and the claddings on both sides is smaller, and the second optical waveguide 9214 has a smaller limiting effect on the light field it transmits. Therefore, the near-field mode spot of the light transmitted by the second optical waveguide 9214 is larger, and the corresponding far-field divergence angle is smaller.

[0280] In some embodiments, a buried heterojunction optical waveguide is provided on the laser chip 920, and the thickness and width of the waveguide core layer in the buried heterojunction optical waveguide are adjusted to reduce the effective refractive index difference of the buried heterojunction optical waveguide, increase the near-field mode spot size of the output light of the buried heterojunction optical waveguide, and reduce the far-field divergence angle of the output light of the buried heterojunction optical waveguide. Ultimately, the near-field mode spot of the output light of the buried heterojunction optical waveguide can be made approximately circular, the ratio of the lateral divergence angle to the longitudinal divergence angle is close to 1:1, and the full width at half maximum (FWHM) of the divergence angle is less than 30°.

[0281] In the optical module provided by the embodiments of the present disclosure, in an EML laser chip with a rate of 100Gbuad and above, the EAM modulator needs to adopt a deep-etched waveguide structure and increase the number of quantum wells (QWs) to ensure the modulation rate in order to increase the modulation rate. However, this will sacrifice the far-field divergence angle of light, resulting in a low coupling efficiency between the EML laser chip and the optical fiber. The present disclosure additionally connects a transition optical waveguide and a buried heterojunction optical waveguide behind the deep-etched optical waveguide of the EAM modulator, and achieves a coupling connection between the deep-etched optical waveguide and the buried heterojunction optical waveguide through the transition optical waveguide. The buried heterojunction optical waveguide optimizes the near-field mode spot size and far-field divergence angle of the EML laser chip while ensuring high light transmittance, thereby improving the coupling efficiency between the EML laser chip and the optical fiber, thereby realizing the preparation of ultra-high-speed EML laser chips.

[0282] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them. Although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present disclosure.

[0283] Since the above embodiments are all described by reference in combination with other embodiments, different embodiments have the same parts, and the same and similar parts between the various embodiments in this specification can be referred to each other. No further detailed explanation is given here.

[0284] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the disclosure of this application. This application is intended to cover any variations, uses, or adaptations of the present invention that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered merely as exemplary, and the true scope and spirit of the present application are indicated by the claims.

[0285] The above-described embodiments of the present application do not constitute a limitation on the scope of protection of the present application.

Claims

1. An optical module, comprising: Circuit boards; A light emitting component is electrically connected to the circuit board, and is used to generate and output an optical signal; wherein the light emitting component includes: A substrate, with a power supply line and a high-frequency signal line respectively formed on the surface; A laser chip is disposed on the substrate, and the laser chip comprises: a light emitting area, electrically connected to the power supply line, the light emitting area being configured to generate a light beam; a modulation area, electrically connected to the high-frequency signal line, the modulation area being connected to the light-emitting area, and the modulation area being configured to modulate the light beam; A first optical waveguide is coupled to the modulation area, the waveguide core layer of the first optical waveguide has a first width and a first thickness, and the first optical waveguide is configured to transmit the modulated light output by the modulation area; a second optical waveguide that does not match the mode field of the first optical waveguide, wherein the waveguide core layer of the second optical waveguide has a second width and a second thickness, wherein the second width is smaller than the first width, and the second thickness is smaller than the first thickness, so as to reduce the effective refractive index of the waveguide core layer of the second optical waveguide and reduce the effective refractive index difference between the waveguide core layer and the cladding of the second optical waveguide; a third optical waveguide, wherein a light input end is coupled to a light output end of the first optical waveguide, a light output end of the third optical waveguide is coupled to the second optical waveguide, and the third optical waveguide is configured to achieve a transition connection between the first optical waveguide and the second optical waveguide; An adapter plate, whose two ends are respectively fixed to the surface of the substrate and the surface of the laser chip, and a conductive line and a signal line are respectively formed on the surface of the adapter plate; one end of the conductive line is electrically connected to the power supply line, and the other end of the conductive line is electrically connected to the light-emitting area to achieve a power supply connection between the substrate and the laser chip; one end of the signal line is electrically connected to the high-frequency signal line, and the other end of the signal line is electrically connected to the modulation area to achieve a signal connection between the substrate and the laser chip.

2. The optical module according to claim 1, wherein: The first optical waveguide is a deep-etched optical waveguide, and a first effective refractive index difference exists between a waveguide core layer and a cladding layer of the first optical waveguide; The second optical waveguide is a buried heterojunction optical waveguide, and a second effective refractive index difference exists between a waveguide core layer and a cladding layer of the second optical waveguide; A third effective refractive index difference exists between the waveguide core layer and the cladding layer of the third optical waveguide, wherein the third effective refractive index difference is smaller than the first effective refractive index difference and greater than the second effective refractive index difference.

3. The optical module according to claim 1, wherein: The third optical waveguide includes a first tapered optical waveguide and a second tapered optical waveguide connected to each other, the light input end of the first tapered optical waveguide is coupled to the light output end of the first optical waveguide, and the light output end of the second tapered optical waveguide is coupled to the light input end of the second optical waveguide; Along the emission direction of the modulated light, the width of the first tapered optical waveguide gradually increases, and the width of the second tapered optical waveguide gradually decreases, the width dimension of the light input end of the first tapered optical waveguide is equal to the width dimension of the light output end of the first optical waveguide, and the width dimension of the light output end of the second tapered optical waveguide is equal to the width dimension of the light input end of the second optical waveguide.

4. The optical module according to claim 1, wherein: The first width is 1 to 2 μm, and the first thickness is 150 to 300 nm; The second width is 0.5-2 nm, and the second thickness is 150-300 nm.

5. The optical module according to claim 4, wherein: The first width is 2 μm, and the first thickness is 300 nm; the second width is 2 nm, and the second thickness is 150 nm.

6. The optical module according to claim 1, wherein: The length of the third optical waveguide is 30-150 μm.

7. The optical module according to claim 6, wherein: The length of the third optical waveguide is 50-100 μm.

8. The optical module according to claim 1, wherein: The waveguide core layers of the first optical waveguide, the second optical waveguide and the third optical waveguide are all InGaAsP core layers.

9. The optical module according to claim 1, wherein: The surface of the circuit board is respectively formed with a driving signal line, a power supply pad and a ground pad; The surface of the substrate is respectively formed with a ground conductive area, a power supply line and a high-frequency signal line, wherein the power supply line is connected to the high-frequency signal line and the ground conductive area. The electrical area is not connected, the ground conductive area is wire-connected to the ground pad, one end of the power supply line is wire-connected to the power supply pad, and one end of the high-frequency signal line is wire-connected to the drive signal line; A light-emitting electrode and a modulation electrode are respectively formed on the surface of the laser chip, wherein the light-emitting electrode is connected to the light-emitting area, and the modulation electrode is connected to the modulation area; A grounding conductive layer, a conductive wire and a signal wire are respectively formed on the surface of the adapter plate, the conductive wire is not connected to the signal wire and the grounding conductive layer, one end of the conductive wire is welded to the light-emitting electrode, and the other end of the conductive wire is welded to the other end of the power supply wire to transmit a bias current to the light-emitting area; one end of the signal wire is welded to the modulation electrode, and the other end of the signal wire is welded to the other end of the high-frequency signal line to transmit a current signal to the modulation area.

10. The optical module according to claim 9, wherein: A second resistor is also disposed on the side of the adapter plate facing the substrate, one end of the second resistor is connected to the signal line, and the other end of the second resistor is connected to the ground conductive layer.

11. The optical module according to claim 9, wherein: The power supply line is provided with a first metal protrusion, the first metal protrusion protrudes from the substrate, and the first metal protrusion is welded to the conductive line; A fifth metal protrusion is disposed on the high-frequency signal line, the fifth metal protrusion protrudes from the substrate, and the fifth metal protrusion is welded to the signal line.

12. The optical module according to claim 11, wherein: A first grounding electrode and a second grounding electrode are disposed on the top surface of the laser chip, the first grounding electrode and the second grounding electrode are located on both sides of the modulation electrode, and the distance between the first grounding electrode and the modulation electrode is equal to the distance between the second grounding electrode and the modulation electrode; The first grounding electrode is welded to the second grounding electrode and the grounding conductive layer, and the grounding conductive layer is welded to the grounding conductive area.

13. The optical module according to claim 12, wherein: A first grounding column and a second grounding column are disposed on the grounding conductive area. The first grounding column and the second grounding column are located on both sides of the high-frequency signal line. The first grounding column, the second grounding column and the grounding conductive layer are welded.

14. The optical module according to claim 13, wherein: The first grounding column and the second grounding column are located on both sides of the fifth metal protrusion, and the distance between the first grounding column and the fifth metal protrusion is equal to the distance between the second grounding column and the fifth metal protrusion.

15. The optical module according to claim 11, wherein: The light-emitting electrode is provided with a second metal protrusion, the adapter plate is provided with a third metal protrusion and a fourth metal protrusion, the third metal protrusion and the fourth metal protrusion are connected to the conductive wire, the third metal protrusion is welded to the first metal protrusion, and the fourth metal protrusion is welded to the second metal protrusion; A sixth metal protrusion is disposed on the modulation electrode, a seventh metal protrusion and an eighth metal protrusion are disposed on the adapter plate, the seventh metal protrusion is welded to the fifth metal protrusion, and the eighth metal protrusion is welded to the sixth metal protrusion.

16. The optical module according to claim 1, wherein: The substrate is a ceramic substrate, and the adapter plate is a ceramic adapter plate.

17. The optical module according to claim 11, wherein: The power supply line includes a first power supply line, a second power supply line and a third power supply line, one end of the first power supply line is connected to the power supply pad by wire bonding, the other end of the first power supply line is connected to one end of the second power supply line, the other end of the second power supply line is connected to one end of the third power supply line, and the other end of the third power supply line is welded to the conductive wire; The third power supply line is located between the laser chip and the high-frequency signal line, and the conductive line is parallel to the signal line.

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