Optical module and hybrid integrated optical amplification chip

Abstract

The invention provides an optical module, a hybrid integrated optical amplification chip, an optical module optical fiber array, an optical modulation chip and a hybrid integrated optical amplification chip. The optical fiber array transmits to-be-modulated light into the light modulation chip, and the light modulator modulates the to-be-modulated light and then outputs first modulated light and second modulated light. A first optical amplifier, a second optical amplifier, a first optical waveguide and a second optical waveguide are integrated in the hybrid integrated optical amplification chip. The first modulated light and the second modulated light are output and transmitted into the hybrid integrated light amplification chip, and the first optical amplifier and the second optical amplifier amplify the first modulated light and the second modulated light respectively. And the amplified first modulated light and the amplified second modulated light return to the optical modulation chip along the first optical waveguide and the second optical waveguide respectively for wave combination. According to the hybrid integrated optical amplification chip, the gain characteristic of the optical amplifier and the low transmission loss characteristic of the silicon-based waveguide can be exerted at the same time, and the stability of an optical path is improved.

Description

Technical Field

[0001] The present disclosure relates to the field of optical communication technologies, and particularly to an optical module and a hybrid integrated optical amplifier chip. Background Art

[0002] With the development of new services and application models such as cloud computing, mobile Internet, and video, the progress of optical communication technologies has become increasingly important. In optical communication technologies, an optical module, as one of the key components in optical communication devices, can realize the conversion between optical and electrical signals; during the development of optical communication technologies, it is required that the data transmission rate of the optical module continues to increase.

[0003] In the optical path of the optical module, an optical amplification structure is usually required to increase the optical emission power, thereby supporting an optical network with a large beam splitting ratio. Summary of the Invention

[0004] The present disclosure provides an optical module and a hybrid integrated optical amplifier chip to increase the optical emission power of the optical module.

[0005] The optical module provided by the present disclosure includes:

[0006] A circuit board with a notch on its surface;

[0007] A substrate connected to the circuit board through the notch;

[0008] An optical fiber array disposed on the surface of the substrate for transmitting the optical signal to be modulated and the multiplexed modulated optical signal;

[0009] An optical modulation chip disposed on the surface of the substrate and coupled to the optical fiber array for receiving the optical signal to be modulated output by the optical fiber array. An optical modulator and an optical multiplexer are respectively integrated inside the optical modulation chip. The optical modulator is used to modulate the optical signal to be modulated and respectively output a first modulated optical signal and a second modulated optical signal, and the polarization states of the first modulated optical signal and the second modulated optical signal are different;

[0010] The hybrid integrated optical amplification chip is disposed on the surface of the substrate and is coupled to the optical modulation chip. A first optical amplifier, a second optical amplifier, a first optical waveguide optically connected to the first optical amplifier, and a second optical waveguide optically connected to the second optical amplifier are respectively integrated inside the hybrid integrated optical amplification chip. Wherein, both the first optical amplifier and the second optical amplifier are polarization state devices. The first optical amplifier has a first preset polarization state to optically amplify the first modulated light output by the optical modulation chip, and the second optical amplifier has a second preset polarization state to optically amplify the second modulated light output by the optical modulation chip. The first optical waveguide is used to return the amplified first modulated light to the optical modulation chip and access it to the optical multiplexer. The second optical waveguide is used to return the amplified first modulated light to the optical modulation chip and access it to the optical multiplexer. The amplified first modulated light and the amplified second modulated light are multiplexed in the optical multiplexer.

[0011] In the optical module and the hybrid integrated optical amplification chip provided by the present disclosure, the optical module includes a circuit board and a substrate. The surface of the circuit board has a notch, and the substrate is electrically connected to the circuit board through the notch. An optical fiber array, an optical modulation chip, and a hybrid integrated optical amplification chip are respectively provided on the surface of the substrate. The optical fiber array is used to transmit the optical signal to be modulated into the optical modulation chip. An optical modulator and an optical multiplexer are respectively integrated in the optical modulation chip. The optical modulator is used to modulate the optical signal to be modulated and respectively output a first modulated optical signal and a second modulated optical signal, wherein the polarization states of the first modulated optical signal and the second modulated optical signal are different. The hybrid integrated optical amplification chip is coupled to the optical modulation chip. A first optical amplifier, a second optical amplifier, a first optical waveguide optically connected to the first optical amplifier, and a second optical waveguide optically connected to the second optical amplifier are respectively integrated in the hybrid integrated optical amplification chip. Wherein, the first optical amplifier and the second optical amplifier have good gain characteristics; the first optical waveguide and the second optical waveguide have low transmission losses. Therefore, the hybrid integrated optical amplification chip in the present disclosure not only has good gain characteristics but also has low transmission losses, integrating the advantages of the optical amplifier and the silicon-based waveguide. In the present disclosure, since the polarization states of the first modulated optical signal and the second modulated optical signal are different, the first modulated optical signal and the second modulated optical signal are respectively optically amplified by the first optical amplifier and the second optical amplifier, thereby improving the optical emission power. Exemplarily, the first optical amplifier has a first preset polarization state to optically amplify the first modulated optical signal output by the optical modulation chip, and the second optical amplifier has a second preset polarization state to optically amplify the second modulated optical signal output by the optical modulation chip. Based on this, in the present disclosure, the first modulated optical signal and the second modulated optical signal are respectively output from the optical modulation chip and transmitted into the hybrid integrated optical amplification chip. The first optical amplifier and the second optical amplifier in the hybrid integrated optical amplification chip respectively optically amplify the first modulated optical signal and the second modulated optical signal; then the amplified first modulated optical signal returns to the optical modulation chip along the first optical waveguide and is multiplexed in the optical multiplexer; the amplified second modulated optical signal returns to the optical modulation chip along the second optical waveguide and is multiplexed in the optical multiplexer. The multiplexed optical signal is output from the optical modulation chip and transmitted along the optical fiber array. In the present disclosure, the first optical amplifier and the second optical amplifier are integrated in the hybrid integrated optical amplification chip to respectively optically amplify the first modulated optical signal and the second modulated optical signal, improving the optical amplification efficiency; the first optical waveguide and the second optical waveguide are integrated in the hybrid integrated optical amplification chip to respectively return the amplified first modulated optical signal and the second modulated optical signal to the optical modulation chip. In the present disclosure, integrating the optical amplifier and the silicon-based waveguide on the same chip can simultaneously utilize the gain characteristics of the optical amplifier and the low transmission loss characteristics of the silicon-based waveguide; at the same time, integrating the optical amplification optical path and the return transmission optical path on the same chip is beneficial to ensuring the stability of the optical path; at the same time, integrating each device on the same chip is beneficial to increasing the coupling efficiency with the optical modulation chip. Description of the Drawings

[0012] To more clearly illustrate the technical solutions in the present disclosure, the following will briefly introduce the drawings used in some embodiments of the present disclosure. Obviously, the drawings in the following description are only the drawings of some embodiments of the present disclosure. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings. In addition, the drawings in the following description can be regarded as schematic diagrams, and are not limitations on the actual sizes of the products, the actual processes of the methods, the actual timings of the signals, etc. involved in the embodiments of the present disclosure.

[0013] Figure 1 FIG. is a partial architecture diagram of an optical communication system provided according to some embodiments of the present disclosure;

[0014] Figure 2 FIG. is a partial structure diagram of a host computer provided according to some embodiments of the present disclosure;

[0015] Figure 3 FIG. is a structure diagram of an optical module provided according to some embodiments of the present disclosure;

[0016] Figure 4 FIG. is an exploded view of an optical module provided according to some embodiments of the present disclosure;

[0017] Figure 5 FIG. is an optical amplification structure diagram of a coherent optical module provided according to some embodiments of the present disclosure;

[0018] Figure 6 FIG. is a schematic structural diagram of an optical modulator provided according to some embodiments of the present disclosure;

[0019] Figure 7 FIG. is a schematic coupling structure diagram of a hybrid integrated optical amplification chip and an optical modulation chip provided according to some embodiments of the present disclosure;

[0020] Figure 8 FIG. is another schematic coupling structure diagram of a hybrid integrated optical amplification chip and an optical modulation chip provided according to some embodiments of the present disclosure;

[0021] Figure 9 FIG. is a schematic structural diagram of a first optical amplification unit in a hybrid integrated optical amplification chip provided according to some embodiments of the present disclosure;

[0022] Figure 10 FIG. is a schematic assembly relationship diagram of a circuit board and a substrate provided according to some embodiments of the present disclosure;

[0023] Figure 11 FIG. is a package structure of an optical module provided according to some embodiments of the present disclosure Figure 1 ;

[0024] Figure 12An encapsulation structure of an optical module provided according to some embodiments of the present disclosure Figure 2 ;

[0025] Figure 13 Another encapsulation structure of an optical module provided according to some embodiments of the present disclosure Figure 1 ;

[0026] Figure 14 Another encapsulation structure of an optical module provided according to some embodiments of the present disclosure Figure 2 ;

[0027] Figure 15 Another encapsulation structure of an optical module provided according to some embodiments of the present disclosure Figure 3 ;

[0028] Figure 16 An encapsulation structure diagram of end-face coupling between an optical modulation chip and a hybrid integrated optical amplification chip provided according to some embodiments of the present disclosure;

[0029] Figure 17 An exploded view of the encapsulation of end-face coupling between an optical modulation chip and a hybrid integrated optical amplification chip provided according to some embodiments of the present disclosure;

[0030] Figure 18 An exploded view of the encapsulation of lens coupling between an optical modulation chip and a hybrid integrated optical amplification chip provided according to some embodiments of the present disclosure;

[0031] Figure 19 An encapsulation structure diagram between a substrate, an optical modulation chip, and a hybrid integrated optical amplification chip provided according to some embodiments of the present disclosure;

[0032] Figure 20 An exploded view of the encapsulation between a substrate, an optical modulation chip, and a hybrid integrated optical amplification chip provided according to some embodiments of the present disclosure;

[0033] Figure 21 A top view of the encapsulation of end-face coupling between an optical modulation chip and a hybrid integrated optical amplification chip provided according to some embodiments of the present disclosure;

[0034] Figure 22 A top view of the encapsulation of lens coupling between an optical modulation chip and a hybrid integrated optical amplification chip provided according to some embodiments of the present disclosure;

[0035] Figure 23 An optical path schematic diagram corresponding to the coupling method between an optical modulation chip and a hybrid integrated optical amplification chip in an optical module provided according to some embodiments of the present disclosure;

[0036] Figure 24It is a schematic optical path diagram corresponding to another coupling method between an optical modulation chip and a hybrid integrated optical amplifier chip in an optical module provided according to some embodiments of the present disclosure. Detailed implementation manners

[0037] Hereinafter, some embodiments of the present disclosure will be described clearly and in detail with reference to the accompanying drawings. However, the described embodiments are only a part of the embodiments of the present disclosure, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments provided by the present disclosure fall within the protection scope of the present disclosure.

[0038] Unless otherwise required by the context, throughout the specification and claims, the term "comprising" is interpreted as open and inclusive, that is, "including, but not limited to"; the terms "first" and "second" cannot be understood as indicating or implying relative importance or an upper limit on quantity; the term "a plurality" means two or more; the term "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or integrated, can be directly connected, or indirectly connected through an intermediate medium; the use of the term "suitable for" or "configured to" means open and inclusive language, which does not exclude a device suitable for or configured to perform additional tasks or steps; descriptions such as "parallel", "perpendicular", "same", "consistent", "flush", etc. do not limit to absolute mathematical theory relationships, but also include an acceptable error range in practice, and also include differences formed due to manufacturing reasons based on the same design concept.

[0039] In optical communication technology, in order to establish information transmission between information processing devices, it is necessary to load information onto light and utilize the propagation of light to achieve information transmission. Here, the light loaded with information is an optical signal. When the optical signal is transmitted in an information transmission device, the loss of optical power can be reduced, so that high-speed, long-distance, and low-cost information transmission can be achieved. The signals that information processing devices can recognize and process are electrical signals. Information processing devices generally include an Optical Network Unit (ONU), a gateway, a router, a switch, a mobile phone, a computer, a server, a tablet computer, a television, etc., and information transmission devices generally include optical fibers and optical waveguides, etc.

[0040] Optical modules can convert optical signals into electrical signals between information processing devices and information transmission devices. For example, at least one of the optical signal input or output ends of an optical module is connected to an optical fiber, and at least one of the electrical signal input or output ends of the optical module is connected to an optical network terminal. A first optical signal from the optical fiber is transmitted to the optical module, which converts the first optical signal into a first electrical signal and transmits the first electrical signal to the optical network terminal. A second electrical signal from the optical network terminal is transmitted to the optical module, which converts the second electrical signal into a second optical signal and transmits the second optical signal to the optical fiber. Because multiple information processing devices can transmit information via electrical signals, at least one of the multiple information processing devices needs to be directly connected to the optical module, rather than all of them. Here, the information processing device directly connected to the optical module is referred to as the optical module's host computer. Furthermore, the optical signal input or output end of the optical module can be referred to as an optical port, and the electrical signal input or output end of the optical module can be referred to as an electrical port.

[0041] Figure 1 FIG. 1 is a partial structural diagram of an optical communication system according to some embodiments. Figure 1 As shown, the optical communication system mainly includes a remote information processing device 1000 , a local information processing device 2000 , a host computer 100 , an optical module 200 , an optical fiber 101 and a network cable 103 .

[0042] One end of optical fiber 101 extends toward remote information processing device 1000, and the other end of optical fiber 101 is connected to optical module 200 through the optical port of optical module 200. Optical signals can be totally reflected in optical fiber 101, and the propagation of the optical signal in the direction of total reflection can almost maintain the original optical power. The optical signal undergoes multiple total reflections in optical fiber 101 to transmit the optical signal from remote information processing device 1000 to optical module 200, and vice versa, thereby achieving long-distance, low-power information transmission.

[0043] The optical communication system may include one or more optical fibers 101, and the optical fibers 101 may be detachably connected or fixedly connected to the optical module 200. The host computer 100 is configured to provide data signals to the optical module 200, receive data signals from the optical module 200, or monitor or control the operating status of the optical module 200.

[0044] The host computer 100 includes a substantially rectangular housing and an optical module interface 102 disposed on the housing. The optical module interface 102 is configured to connect to the optical module 200 to establish a unidirectional or bidirectional electrical signal connection between the host computer 100 and the optical module 200.

[0045] The host computer 100 further includes an external power interface, which can be connected to an electrical signal network. For example, the external power interface includes a Universal Serial Bus (USB) interface or a network cable interface 104. The network cable interface 104 is configured to be connected to a network cable 103, so that the host computer 100 establishes a unidirectional or bidirectional electrical signal connection with the network cable 103. One end of the network cable 103 is connected to the local information processing device 2000, and the other end of the network cable 103 is connected to the host computer 100, so as to establish an electrical signal connection between the local information processing device 2000 and the host computer 100 through the network cable 103. For example, a third electrical signal sent by the local information processing device 2000 is transmitted into the host computer 100 through the network cable 103. The host computer 100 generates a second electrical signal according to the third electrical signal. The second electrical signal from the host computer 100 is transmitted to the optical module 200. The optical module 200 converts the second electrical signal into a second optical signal and transmits the second optical signal to the optical fiber 101. The second optical signal is transmitted in the optical fiber 101 to the remote information processing device 1000. For example, a first optical signal from the remote information processing device 1000 propagates through the optical fiber 101. The first optical signal from the optical fiber 101 is transmitted to 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 to the host computer 100. The host computer 100 generates a fourth electrical signal according to the first electrical signal and transmits the fourth electrical signal into the local information processing device 2000. It should be noted that the optical module is a tool for realizing the mutual conversion between optical signals and electrical signals. During the above conversion process of optical signals and electrical signals, the information does not change, but the encoding and decoding methods of the information can change.

[0046] In addition to including an optical network terminal, the host computer 100 further includes an Optical Line Terminal (OLT), an Optical Network Terminal (ONT), or a data center server, etc.

[0047] Figure 2 It is a partial structural diagram of a host computer according to some embodiments. To clearly show the connection relationship between the optical module 200 and the host computer 100, Figure 2 only the structure of the host computer 100 related to the optical module 200 is shown. As Figure 2 shown, the host computer 100 further includes a PCB circuit board 105 disposed in the housing, a cage 106 disposed on the surface of the PCB circuit board 105, a radiator 107 disposed on the cage 106, and an electrical connector disposed inside the cage 106. The electrical connector is configured to access the electrical port of the optical module 200; the radiator 107 has raised structures such as fins for increasing the heat dissipation area.

[0048] The optical module 200 is inserted into the cage 106 of the host computer 100. The cage 106 fixes the optical module 200, and the heat generated by the optical module 200 is conducted to the cage 106 and then diffused through the heat sink 107. After the optical module 200 is inserted into the cage 106, the electrical port of the optical module 200 is connected to the electrical connector inside the cage 106, so as to establish a two-way electrical signal connection between the optical module 200 and the host computer 100. In addition, the optical port of the optical module 200 is connected to the optical fiber 101, so as to establish a two-way optical signal connection between the optical module 200 and the optical fiber 101.

[0049] Figure 3 It is a structural diagram of an optical module according to some embodiments. Figure 4 It is an exploded view of an optical module according to some embodiments. As Figure 3 and Figure 4 shown, the optical module 200 includes a shell, a circuit board 300 disposed in the shell, an optical transmitting component 400, and an optical receiving component 500. However, the present disclosure is not limited thereto. In some embodiments, the optical module 200 includes one of the optical transmitting component 400 and the optical receiving component 500.

[0050] The shell includes an upper shell 201 and a lower shell 202. The upper shell 201 covers the lower shell 202 to form the above-mentioned shell having two openings 204 and 205; the outer contour of the shell generally presents a square body.

[0051] In some embodiments, the lower shell 202 includes a bottom plate 2021 and two lower side plates 2022 located on both sides of the bottom plate 2021 and perpendicular to the bottom 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.

[0052] In some embodiments, the lower shell 202 includes a bottom plate 2021 and two lower side plates 2022 located on both sides of the bottom plate 2021 and perpendicular to the bottom 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 perpendicular to the cover plate 2011. The two upper side plates are combined with the two lower side plates 2022 to realize the upper shell 201 covering the lower shell 202.

[0053] The direction where the connection line of the two openings 204 and 205 is located may be consistent with the length direction of the optical module 200 or may not be consistent with the length direction of the optical module 200. For example, the opening 204 is located at the end of the optical module 200 ( Figure 3 the left end), and the opening 205 is also located at the end of the optical module 200 ( Figure 3The right end). Alternatively, the opening 204 is located at the end of the optical module 200, while the opening 205 is located at the side of the optical module 200. The opening 204 is an electrical port, and the gold finger 301 of the circuit board 300 extends out from the opening 204 and is inserted into the electrical connector of the host computer 100; the opening 205 is an optical port and is configured to access the external optical fiber 101 so that the optical fiber 101 connects the optical transmitting component 400 and the optical receiving component 500 in the optical module 200.

[0054] Adopting the assembly method of combining the upper housing 201 and the lower housing 202 facilitates the installation of the circuit board 300, the optical transmitting component 400, the optical receiving component 500, etc. into the above-mentioned housing, and the upper housing 201 and the lower housing 202 can encapsulate and protect the above-mentioned devices. In addition, when assembling the circuit board 300, the optical transmitting component 400 and the optical receiving component 500, etc., it is convenient for the deployment of the positioning components, heat dissipation components and electromagnetic shielding components of these devices, which is conducive to the automated implementation of production.

[0055] In some embodiments, the upper housing 201 and the lower housing 202 are made of metal materials, which is conducive to achieving electromagnetic shielding and heat dissipation.

[0056] In some embodiments, the optical module 200 further 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.

[0057] For example, the unlocking component 600 is located outside the two lower side plates 2022 of the lower housing 202 and includes an engaging component that matches the cage 106 of the host computer 100. When the optical module 200 is inserted into the cage 106, the engaging component of the unlocking component 600 fixes the optical module 200 in the cage 106; when the unlocking component 600 is pulled, the engaging component of the unlocking component 600 moves accordingly, thereby changing the connection relationship between the engaging component and the host computer to release the fixation of the optical module 200 and the host computer, so that the optical module 200 can be withdrawn from the cage 106.

[0058] The circuit board 300 includes circuit traces, electronic components, and chips, etc. The electronic components and chips are connected according to the circuit design through the circuit traces to achieve functions such as power supply, electrical signal transmission, and grounding. The electronic components can include, for example, capacitors, resistors, triodes, and Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs). The chips can include, for example, Microcontroller Units (MCUs), laser driver chips, Transimpedance Amplifiers (TIAs), limiting amplifiers, Clock and Data Recovery (CDR) chips, power management chips, and Digital Signal Processing (DSP) chips.

[0059] The circuit board 300 is generally a rigid circuit board. Due to its relatively hard material, the rigid circuit board can also achieve a bearing function. For example, the rigid circuit board can stably bear the above-mentioned electronic components and chips; the rigid circuit board can also be inserted into the electrical connectors in the cage 106 of the host computer 100.

[0060] The circuit board 300 also includes a gold finger 301 formed on its end surface. 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 conducts with the electrical connectors in the cage 106. The gold finger 301 can be provided only on the surface of one side of the circuit board 300 (for example, Figure 4 the upper surface shown), or can be provided on the upper and lower surfaces of the circuit board 300 to provide a larger number of pins, so as to adapt to occasions with a large demand for the number of pins. The gold finger 301 is configured to establish an electrical connection with the host computer to achieve functions such as power supply, grounding, Inter-Integrated Circuit (I2C) signal transmission, and data signal transmission. Of course, flexible circuit boards are also used in some optical modules. Flexible circuit boards are generally used in cooperation with rigid circuit boards as a supplement to the rigid circuit boards.

[0061] At least one of the optical emission component 400 or the optical reception component 500 is located on the side of the circuit board 300 away from the gold finger 301.

[0062] In some embodiments, the optical emission component 400 and the optical reception component 500 are physically separated from the circuit board 300 respectively, and then are electrically connected to the circuit board 300 through corresponding flexible circuit boards or electrical connectors respectively.

[0063] In some embodiments, at least one of the light emitting component or the light receiving component may be directly disposed on the circuit board 300. For example, at least one of the light emitting component or the light receiving component may be disposed on the surface of the circuit board 300 or on the side of the circuit board 300.

[0064] In some embodiments, implementing the optoelectronic conversion function through an optical modulation chip such as a silicon photonics chip or a thin film lithium niobate optical chip has become a mainstream solution currently adopted by high-speed optical modules. Light or an optical signal can enter and exit the optical modulation chip, and an optical modulator and an optical multiplexer are integrated inside the optical modulation chip. Exemplarily, the light to be modulated contained in the light not carrying data enters the optical modulation chip, and the optical modulator inside the optical modulation chip modulates the light to be modulated to load data onto the light to be modulated, thereby generating a first modulated light and a second modulated light respectively. The first modulated light and the second modulated light are multiplexed by the optical multiplexer to generate an optical emission signal, and the optical emission signal is output from the optical modulation chip.

[0065] In the present disclosure, in order to increase the optical emission power, a semiconductor optical amplifier (SOA) chip may be disposed on the output optical path of the light source. However, this method has a limited improvement in the optical emission power. To further increase the optical emission power, an SOA may be integrated inside the optical modulation chip. Exemplarily, the optical modulation chip is a silicon photonics chip. The SOA is an InP-based optical amplifier. The integration process of integrating an InP-based optical amplifier in a silicon photonics chip is difficult to achieve.

[0066] In the present disclosure, to further increase the optical emission power, the first modulated light and the second modulated light are output from the optical modulation chip, and are respectively optically amplified by an optical amplification structure disposed outside the optical modulation chip. Then, the amplified first modulated light and second modulated light return to the optical modulation chip and are multiplexed in the optical multiplexer to generate an optical emission signal, thereby increasing the optical emission power. Among them, the optical amplification structure includes an SOA optical amplifier. Exemplarily, the semiconductor optical amplifier chip is a monolithic integrated SOA chip; or, the semiconductor optical amplifier chip is a hybrid integrated optical amplifier chip.

[0067] In some embodiments, an optical modulator and an optical multiplexer are easily integrated inside the optical modulation chip. An optical amplification structure is provided outside the optical modulation chip. After the optical modulator modulates the optical signal to be modulated, a first modulated optical signal and a second modulated optical signal are respectively output. Since the optical modulator performs coherent modulation, the polarization states of the first modulated optical signal and the second modulated optical signal are different. Since the SOA optical amplifier is a polarization-state device, the optical amplification structure respectively includes a first optical amplifier and a second optical amplifier. The first optical amplifier amplifies the first modulated optical signal, and the second optical amplifier amplifies the second modulated optical signal. Then, the amplified first modulated optical signal and second modulated optical signal are transmitted into the optical modulation chip, and the two are multiplexed in the optical multiplexer to generate an optical transmission signal.

[0068] In some embodiments, the optical amplification structure provided outside the optical modulation chip may be a discrete optical device or a hybrid integrated optical chip. Hereinafter, an example in which the optical amplification structure provided outside the optical modulation chip is a discrete optical device will be used for exemplary illustration.

[0069] In the present disclosure, the optical module may include an optical fiber array. The optical fiber array can transmit the optical signal to be modulated into the optical modulation chip and can also transmit the optical transmission signal generated by the optical modulation chip to the outside.

[0070] The optical module may include an optical modulation chip. An optical modulator and an optical multiplexer are respectively integrated inside the optical modulation chip. The optical modulation chip is electrically connected to a circuit board and is coupled to the optical fiber array for receiving the optical signal to be modulated output by the optical fiber array. The optical modulator is configured to modulate the optical signal to be modulated and respectively output a first modulated optical signal and a second modulated optical signal. The polarization states of the first modulated optical signal and the second modulated optical signal are different.

[0071] The optical module may include a first optical amplifier. Exemplarily, the first optical amplifier may be a monolithically integrated InP-based SOA optical amplifier. The first optical amplifier is provided outside the optical modulation chip and on the output optical path of the first modulated optical signal. The first optical amplifier is a polarization-state device and has a preset polarization state to amplify the first modulated optical signal.

[0072] The optical module may include a second optical amplifier. Exemplarily, the second optical amplifier may be a monolithically integrated InP-based SOA optical amplifier. The second optical amplifier is provided outside the optical modulation chip and on the output optical path of the second modulated optical signal. The second optical amplifier is a polarization-state device and has a preset polarization state to amplify the second modulated optical signal.

[0073] Since the polarization states of the first modulated optical signal and the second modulated optical signal are different, the polarization states of the first optical amplifier and the second optical amplifier are also different.

[0074] The optical module may include a first reflecting surface group. The first reflecting surface group is disposed outside the optical modulation chip and is configured to return the amplified first modulated light to the inside of the optical modulation chip and access it to an optical multiplexer.

[0075] The optical module may include a second reflecting surface group. The second reflecting surface group is disposed outside the optical modulation chip and is configured to return the amplified second modulated light to the inside of the optical modulation chip and access it to the optical multiplexer.

[0076] The amplified first modulated light and the amplified second modulated light are multiplexed in the optical multiplexer to synthesize an optical transmission signal.

[0077] In some embodiments, the first reflecting surface group respectively includes opposite first and second reflecting surfaces.

[0078] The first reflecting surface is configured to reflect the amplified first modulated light to the second reflecting surface. The second reflecting surface is configured to reflect the amplified first modulated light into the optical modulation chip.

[0079] The incident light surface of the first reflecting surface faces the first optical amplifier, and the outgoing light surface faces the second reflecting surface.

[0080] The incident light surface of the second reflecting surface faces the first emitting surface, and the outgoing light surface faces the optical modulation chip.

[0081] Exemplarily, the first reflecting surface and the second reflecting surface may be a first mirror and a second mirror respectively.

[0082] In some embodiments, the second reflecting surface group respectively includes opposite third and fourth reflecting surfaces. The third reflecting surface is configured to reflect the amplified second modulated light to the fourth reflecting surface. The fourth reflecting surface is configured to reflect the amplified second modulated light output from the optical modulation chip into the optical modulation chip.

[0083] Exemplarily, the third reflecting surface and the fourth reflecting surface may be a third mirror and a fourth mirror respectively.

[0084] The incident light surface of the third reflecting surface faces the second optical amplifier, and the outgoing light surface faces the fourth reflecting surface.

[0085] The incident light surface of the fourth reflecting surface faces the third emitting surface, and the outgoing light surface faces the optical modulation chip.

[0086] In some embodiments, the optical modulation chip respectively includes a first optical port, a second optical port, a third optical port, a fourth optical port, a fifth optical port, a sixth optical port, and a seventh optical port.

[0087] The first optical port is used for coupling connection with an optical fiber array to transmit the optical transmission signal to the outside.

[0088] The second optical port is used for coupling connection with the optical fiber array to receive the light to be modulated.

[0089] The third optical port is used for coupling connection with an optical fiber array to receive an optical signal from the outside.

[0090] The fourth optical port is coupled to the first optical amplifier to transmit the first modulated light into the first optical amplifier.

[0091] The fifth optical port is coupled to the second optical amplifier to transmit the second modulated light into the second optical amplifier.

[0092] The sixth optical port is coupled to the second reflecting surface group to transmit the second modulated light amplified by the second optical amplifier into the optical modulation chip.

[0093] The seventh optical port is coupled to the first reflecting surface group to transmit the first modulated light amplified by the first optical amplifier into the optical modulation chip.

[0094] In some embodiments, a first mode field converter is formed at the first optical port, a second mode field converter is formed at the second optical port, a third mode field converter is formed at the third optical port, a fourth mode field converter is formed at the fourth optical port, a fifth mode field converter is formed at the fifth optical port, a sixth mode field converter is formed at the sixth optical port, and a seventh mode field converter is formed at the seventh optical port.

[0095] In the present disclosure, a first optical amplifier and a second optical amplifier are respectively provided outside the optical modulation chip. The optical modulation chip outputs the generated first modulated light and second modulated light respectively, and transmits them to the first optical amplifier and the second optical amplifier respectively. The first optical amplifier optically amplifies the first modulated light, and transmits the amplified first modulated light to the optical modulation chip through the first reflecting surface group and accesses the internal optical combiner. The second optical amplifier optically amplifies the second modulated light, and transmits the amplified second modulated light to the optical modulation chip through the second reflecting surface group and accesses the internal optical combiner. The amplified first modulated light and the amplified second modulated light are combined in the optical combiner to synthesize an optical emission signal, which is output to the outside through the optical fiber array. The present disclosure optically amplifies the first modulated light and the second modulated light respectively through the first optical amplifier and the second optical amplifier, thereby increasing the optical emission power.

[0096] Figure 5 It is a structural diagram of optical amplification of a coherent optical module provided according to some embodiments of the present disclosure. As Figure 5As shown, in some embodiments, the optical modulation chip 1100 itself does not have a light source. The optical modulation chip 1100 has an external light source. The light source emits light from the side, and the emitted light enters the optical modulation chip 1100. The light source can be a laser box. A laser is encapsulated inside the laser box. The laser emits light to generate a laser beam. The light source is used to provide the emitted laser to the optical modulation chip 1100. The laser becomes the preferred light source for optical modules and even fiber optic transmission due to its good single-wavelength characteristics and better wavelength tuning characteristics. For other types of light such as LED light, etc., common optical communication systems generally do not use it. Even if such a light source is used in a special optical communication system, there are significant differences in the characteristics of the light source and chip components compared to the laser, resulting in significant technical differences between optical modules using lasers and those using other light sources. Those skilled in the art generally do not think that these two types of optical modules can provide technical inspiration to each other.

[0097] The light emitted by the light source is light that does not carry data. This light that does not carry data includes the light to be modulated. The light to be modulated enters the optical modulation chip 1100. The optical modulation chip 1100 modulates it and loads the electrical signal into the light to be modulated to obtain the light carrying data, that is, to generate an optical emission signal, thereby realizing the emission of the optical signal. External light enters the optical modulation chip 1100, and the optical modulation chip 1100 demodulates it, thereby realizing the reception of the optical signal. Therefore, the optical modulation chip 1100 of the present disclosure integrates the functions of optical modulation and optical demodulation. The optical modulation chip 1100 is essentially an optical modulation and demodulation chip. For the convenience of description, the optical modulation and demodulation chip is described as an optical modulation chip.

[0098] In some embodiments, the optical modulation chip 1100 can be a silicon photonics chip. A modulator is integrated inside the silicon photonics chip, and the modulator can realize the modulation and demodulation of optical signals. Since the silicon photonics chip is easy to etch, other functional devices such as optical splitters, optical combiners, mixers, and photodetectors can be integrated inside it, thereby realizing more functions.

[0099] In some embodiments, the optical modulation chip 1100 can be a thin-film lithium niobate chip. The thin-film lithium niobate has characteristics such as the linear electro-optic effect. An external electric field will cause a linear change in the refractive index in its corresponding direction, making the light wave transmitted in the medium have controllable intensity, phase and other information. Therefore, the thin-film lithium niobate can be selected as the material of the optical modulator to achieve a higher modulation efficiency, etc. At the same time, the optical loss of the thin-film lithium niobate chip is low.

[0100] As Figure 5 As shown, in some embodiments, taking the optical modulation chip 1100 as a silicon photonics chip as an example for exemplary illustration. When the optical modulation chip 1100 is a silicon photonics chip, an optical demodulator 1120, an optical modulator 1130, and an optical multiplexer 1140 are respectively integrated inside.

[0101] Exemplarily, light or an optical signal enters and exits the optical modulation chip 1100 through the optical fiber array 1300; exemplarily, light or an optical signal can also enter and exit the optical modulation chip 1100 through an end-face coupler or the like. In the present disclosure, taking the case where light or an optical signal enters and exits the optical modulation chip 1100 through the optical fiber array 1300 as an example for exemplary illustration.

[0102] In some embodiments, the optical fiber array 1300 respectively includes a first optical fiber ribbon 1311, a second optical fiber ribbon 1312, and a third optical fiber ribbon 1313. The first optical fiber ribbon 1311 is used to output the modulated optical emission signal from the optical modulation chip 1100; the second optical fiber ribbon 1312 is used to transmit the light without data provided by the light source into the optical modulation chip 1100; the third optical fiber ribbon 1313 is used to transmit the optical signal from the outside into the optical modulation chip 1100.

[0103] The optical fiber array 1300 is coupled to the optical modulation chip 1100, and the optical fiber interfaces of the first optical fiber ribbon 1311, the second optical fiber ribbon 1312, and the third optical fiber ribbon 1313 are respectively coupled to the corresponding optical ports of the optical modulation chip 1100. Among them, the optical ports of the optical modulation chip 1100 coupled to the optical fiber array 1300 respectively include a first optical port, a second optical port, and a third optical port. The first optical port is coupled to the optical fiber interface of the first optical fiber ribbon 1311, the second optical port is coupled to the optical fiber interface of the second optical fiber ribbon 1312, and the third optical port is coupled to the optical fiber interface of the third optical fiber ribbon 1313.

[0104] In some embodiments, the optical fiber array 1300 and the optical modulation chip 1100 are coupled by end-face coupling. During end-face coupling, the end face of the optical fiber array 1300 is aligned and coupled with the end face of the optical modulation chip 1100, and a small gap is left between the two end faces. After the optical paths are aligned, an optical adhesive is filled in the small gap to bond the two, thereby realizing hybrid integration in the horizontal direction. Since end-face coupling is calibrated for each chip separately, end-face coupling is beneficial to improving the optical coupling accuracy. Exemplarily, the end-face coupling between the optical fiber array 1300 and the optical modulation chip 1100 can be achieved through a refractive index matching adhesive, which can not only match the refractive indices between the optical fiber array 1300 and the optical modulation chip 1100, but also play a role in fixing their connection after the optical paths are aligned.

[0105] In some embodiments, taking the optical modulation chip 1100 as a silicon photonics chip as an example. For this reason, the mode spot of the single-mode fiber in the fiber array 1300 is circular and relatively large in size, while the mode spot of the optical modulation chip 1100 is elliptical and relatively small in size. If the fiber array 1300 is directly coupled to the optical modulation chip 1100, a relatively large coupling loss will be caused due to the large mode field mismatch. For this reason, a corresponding mode spot converter is formed at the optical port end face of the optical modulation chip 1100 to increase the mode spot size of the optical modulation chip 1100, thereby reducing the mode field adaptation between the fiber and the waveguide and improving the optical coupling efficiency. Among them, the mode spot converter is a horizontal tapered coupler structure, and the light field is expanded through the gradual change of the waveguide width to match the mode spot of the fiber and improve the optical coupling efficiency.

[0106] Exemplarily, a first mode spot converter 1111 is formed at the first optical port of the optical modulation chip 1100, a second mode spot converter 1112 is formed at the second optical port, and a third mode spot converter 1113 is formed at the third optical port. The first mode spot converter 1111 is used to achieve mode spot matching with the first fiber ribbon 1311 and improve the optical coupling efficiency; the second mode spot converter 1112 is used to achieve mode spot matching with the second fiber ribbon 1312 and improve the optical coupling efficiency; the third mode spot converter 1113 is used to achieve mode spot matching with the third fiber ribbon 1313 and improve the optical coupling efficiency.

[0107] The waveguide widths of the first mode spot converter 1111, the second mode spot converter 1112, and the third mode spot converter 1113 gradually become wider in the direction towards the fiber array 1300, so as to obtain a larger mode spot when coupling with the fiber interface of the fiber array 1300, thereby matching the mode spot of the fiber and improving the optical coupling efficiency. Among them, the first mode spot converter 1111 is the mode spot converter corresponding to the output optical port, the second mode spot converter 1112 is the mode spot converter corresponding to the input optical port, and the third mode spot converter 1113 is the mode spot converter corresponding to the input optical port.

[0108] In the present disclosure, the light without data provided by the external light source enters the second optical port of the optical modulation chip 1100 through the second fiber ribbon 1312, and is transmitted into the interior of the optical modulation chip 1100 through the second optical port and the second mode spot converter 1112. The light without data is divided into a certain proportion of first split light and second split light by the optical splitter built in the optical modulation chip 1100. The first split light is used as the light to be modulated and is transmitted into the optical modulator 1130 for modulation, and the second split light is used as the local oscillator light and is transmitted into the optical demodulator 1120 for demodulation.

[0109] In some embodiments, an external optical signal enters the third optical port of the optical modulation chip 1100 through the third optical fiber ribbon 1313, and is transmitted into the optical modulation chip 1100 through the third optical port and the third mode converter 1113, and is coherently demodulated with the local oscillator light in the optical demodulator 1120. Exemplarily, during optical demodulation, the local oscillator light and the external optical signal are mixed in the optical mixer built in the optical modulation chip 1100 to obtain an intermediate frequency signal whose frequency, phase, and amplitude vary according to the same law as the external optical signal. The magnitude of the output photocurrent after coherent mixing is proportional to the product of the external optical signal power and the local oscillator optical signal power. Since the power of the local oscillator light is greater than the power of the external optical signal, the output photocurrent after coherent mixing increases significantly, and the detection sensitivity is thus improved.

[0110] Figure 6 FIG. is a schematic structural diagram of an optical modulator provided according to some embodiments of the present disclosure. As Figure 6 shown, in some embodiments, the optical modulator 1130 is an IQ modulator based on a Mach-Zehnder modulator (MZM), which can implement high-order modulation and load data onto the optical signal to be modulated, thereby generating an optical emission signal. The optical modulator 1130 is a coherent modulator, and its final output is two modulated lights with different polarization states.

[0111] The optical modulator 1130 includes a first I modulator 1131, a first Q modulator 1132, a second I modulator 1133, and a second Q modulator 1134 respectively. The optical signal to be modulated is split into two lights with perpendicular polarization directions by the polarization beam splitter 1135 built in the optical modulation chip 1100, that is, Figure 6 the TE polarized light and the TM polarized light marked in. Among them, the TE polarized light is further split into two lights and enters the first I modulator 1131 and the first Q modulator 1132 respectively; the TM polarized light is also split into two lights and enters the second I modulator 1133 and the second Q modulator 1134 respectively. The first I modulator 1131 and the first Q modulator 1132 perform high-order modulation on the TE polarized light to generate the first modulated light, and the second I modulator 1133 and the second Q modulator 1134 perform high-order modulation on the TM polarized light to generate the second modulated light. Among them, the polarization states of the first modulated light and the second modulated light are different. Exemplarily, the polarization directions of the first modulated light and the second modulated light are perpendicular to each other.

[0112] In the present disclosure, the optical emission power of the optical modulation chip 1100 is increased through an optical amplification structure. The optical amplification structure includes an optical amplification chip, such as an SOA optical chip. The optical amplification chip, such as an SOA optical chip, is an active device that uses a III-V compound material as the gain medium and provides gain to incoming photons by injecting current. The III-V compound material is a direct bandgap material with a strong linear electro-optic Pockels effect, making it easy to achieve the optical amplification function. The III-V compound material may include III-V materials such as InP, GaAs, and AlGaAs. In some embodiments, the optical amplification chip may be a monolithic integrated InP-based SOA optical amplifier. In some embodiments, the optical amplification chip may be a hybrid integrated optical chip.

[0113] Since the polarization states of the first modulated light and the second modulated light are different, and the SOA optical chip is a polarization state element with polarization characteristics, which means it is sensitive to the polarization state of the input light and has different gain effects on the input light with different polarization states. Exemplarily, when the polarization state of the SOA optical chip is the same as that of the input light, the gain effect on the input light is more significant. If the first modulated light and the second modulated light generated by the optical modulator 1130 are combined by an optical combiner and then amplified by the SOA optical chip, since the combined optical signal contains two optical signals with different polarization states, the SOA optical chip will have a more significant gain effect on one of the optical signals and a weaker gain effect on the other optical signal, thus reducing the gain effect of the SOA optical signal. Therefore, in the present disclosure, the first modulated light and the second modulated light generated by the optical modulator 1130 are respectively optically amplified, then combined and output.

[0114] In some embodiments, the optical amplification structure is placed outside the optical modulation chip 1100, and the first modulated light and the second modulated light generated by the optical modulator 1130 are respectively output. The optical amplification structure includes two monolithic integrated InP-based SOA optical amplifiers, such as Figure 5 the first InP-based SOA optical amplifier 1200a and the second InP-based SOA optical amplifier 1200b shown, to respectively optically amplify the first modulated light and the second modulated light. Both the first InP-based SOA optical amplifier 1200a and the second InP-based SOA optical amplifier 1200b have gain characteristics and polarization characteristics. The gain characteristics mean that as a direct bandgap material, it can achieve the optical amplification function, and the polarization characteristics mean that it has different gain effects on the input light with different polarization states. Exemplarily, the InP-based SOA optical amplifier has a stronger gain effect on the input light with the same or similar polarization as itself.

[0115] The first modulated light and the second modulated light, which are amplified by the first InP-based SOA optical amplifier 1200a and the second InP-based SOA optical amplifier 1200b respectively, return to the optical modulation chip 1100 and are multiplexed in the optical multiplexer 1140 to generate an optical transmission signal. The optical transmission signal is transmitted out successively through the first mode converter 1111, the first optical port of the optical modulation chip 1100, and the first optical fiber ribbon 1311. Based on the polarization characteristics of the SOA optical amplifier, the first InP-based SOA optical amplifier 1200a has a preset polarization state to optically amplify the first modulated light. Exemplarily, the first InP-based SOA optical amplifier 1200a has the same or a similar polarization state as the first modulated light. The second InP-based SOA optical amplifier 1200b has a preset polarization state to optically amplify the second modulated light. Exemplarily, the second InP-based SOA optical amplifier 1200b has the same or a similar polarization state as the second modulated light. Since the polarization states of the first modulated light and the second modulated light are different, the polarization states of the first InP-based SOA optical amplifier 1200a and the second InP-based SOA optical amplifier 1200b are also different.

[0116] To optically amplify the first modulated light, a first InP-based SOA optical amplifier 1200a, a mirror 1700a, and a mirror 1700b are respectively provided in the free space outside the optical modulation chip 1100. The mirrors 1700a and 1700b are oppositely arranged. The mirror 1700a is used to reflect the first modulated light amplified by the first InP-based SOA optical amplifier 1200a towards the mirror 1700b, and the mirror 1700b is used to reflect the received amplified first modulated light towards the optical modulation chip 1100, so as to return the amplified first modulated light back into the optical modulation chip 1100.

[0117] Among them, since the first modulated light is divergent light when output from the optical modulation chip 1100, a converging lens 1700e is provided between the optical modulation chip 1100 and the first InP-based SOA optical amplifier 1200a, and the amplified first modulated light is re-transmitted into the optical modulation chip 1100 through the converging lens 1700h to improve the optical coupling efficiency.

[0118] A collimating lens is provided between the first InP-based SOA optical amplifier 1200a and the mirror 1700a to enter the mirror 1700a for reflection in the form of parallel light, thereby improving the optical coupling efficiency.

[0119] To optically amplify the second modulated light, a second InP-based SOA optical amplifier 1200b, a mirror 1700c, and a mirror 1700d are respectively provided in the free space outside the optical modulation chip 1100. The mirror 1700c and the mirror 1700d are oppositely arranged. The mirror 1700c is used to reflect the first modulated light amplified by the second InP-based SOA optical amplifier 1200b toward the mirror 1700d, and the mirror 1700d is used to reflect the received amplified second modulated light toward the optical modulation chip 1100, so as to return the amplified second modulated light back into the optical modulation chip 1100.

[0120] Among them, since the second modulated light is divergent light when output from the optical modulation chip 1100, a converging lens 1700f is provided between the optical modulation chip 1100 and the second InP-based SOA optical amplifier 1200b, and the amplified first modulated light is re-transmitted into the optical modulation chip 1100 through the converging lens 1700g to improve the optical coupling efficiency.

[0121] A collimating lens is provided between the second InP-based SOA optical amplifier 1200b and the mirror 1700c to enter the mirror 1700c for reflection in the form of parallel light, thereby improving the optical coupling efficiency.

[0122] The mirror 1700a and the mirror 1700c are staggeredly arranged relative to each other to avoid mutual interference of the optical paths; the mirror 1700b and the mirror 1700d are staggeredly arranged relative to each other to avoid mutual interference of the optical paths.

[0123] The mirror 1700a and the mirror 1700b are arranged on the same axis and are inclined and oppositely arranged. The incident surface of the mirror 1700a faces the first InP-based SOA optical amplifier 1200a, and the exit surface faces the mirror 1700b; the incident surface of the mirror 1700b faces the exit surface of the mirror 1700a, and the exit surface faces the end face of the optical modulation chip 1100.

[0124] The mirror 1700c and the mirror 1700d are arranged on the same axis and are inclined and oppositely arranged. The incident surface of the mirror 1700c faces the second InP-based SOA optical amplifier 1200b, and the exit surface faces the mirror 1700d; the incident surface of the mirror 1700d faces the exit surface of the mirror 1700c, and the exit surface faces the end face of the optical modulation chip 1100.

[0125] In the present disclosure, the first modulated light is output from the optical modulation chip 1100, coupled to the first InP-based SOA optical amplifier 1200a through the converging lens 1200e, and after being amplified by the first InP-based SOA optical amplifier 1200a, coupled to the surface of the reflector 1700a through the collimating lens; the reflector 1700a reflects the amplified first modulated light toward the reflector 1700b, and the reflector 1700b continues to reflect the amplified first modulated light toward the end face of the optical modulation chip 1100, and the converging lens 1700h re-transmits the amplified first modulated light to the optical modulation chip 1100.

[0126] The second modulated light is output from the optical modulation chip 1100, coupled to the second InP-based SOA optical amplifier 1200b through the converging lens 1200f, and after being amplified by the second InP-based SOA optical amplifier 1200b, coupled to the surface of the reflector 1700c through the collimating lens; the reflector 1700c reflects the amplified first modulated light toward the reflector 1700d, and the reflector 1700d continues to reflect the amplified second modulated light toward the end face of the optical modulation chip 1100, and the converging lens 1700g re-transmits the amplified second modulated light to the optical modulation chip 1100.

[0127] The first and second modulated lights are output from the optical modulation chip 1100. They are optically amplified outside the optical modulation chip 1100 and then reflected and retransmitted into the optical modulation chip 1100. The amplified first and second modulated lights are then combined within the optical combiner 1140 to form a combined optical transmit signal. The optical transmit signal is then emitted sequentially through the first spot size converter 1111 of the optical modulation chip 1100, the first optical port of the optical modulation chip 1100, and the first optical fiber ribbon 1311 of the optical fiber array 1300.

[0128] In the present disclosure, first InP-based SOA optical amplifier 1200a, second InP-based SOA optical amplifier 1200b, reflectors 1700a, 1700b, 1700c, and 1700d are independently located outside optical modulation chip 1100, thereby amplifying the first modulated light and the second modulated light, respectively, to increase optical transmission power. First InP-based SOA optical amplifier 1200a and second InP-based SOA optical amplifier 1200b form a monolithic integrated optical amplifier chip.

[0129] In some embodiments, the optical amplification structure disposed outside the optical modulation chip may be a discrete optical device or a hybrid integrated optical chip. The following description takes the optical amplification structure disposed outside the optical modulation chip as a hybrid integrated optical chip as an example.

[0130] Figure 7 Schematic diagram of a coupling structure of a hybrid integrated optical amplification chip and an optical modulation chip provided according to some embodiments of the present disclosure. As Figure 7 shown, the optical amplification structure provided outside the optical modulation chip is a hybrid integrated optical chip. The optical amplification chip is a hybrid integrated optical amplification chip 1200.

[0131] In some embodiments, the hybrid integrated optical amplification chip 1200 is an InP / Si hybrid integrated optical amplification chip. Exemplarily, an InP-based SOA optical amplifier and a Si waveguide are integrated in the InP / Si hybrid integrated optical amplification chip. The InP-based SOA optical amplifier has good gain characteristics based on material properties. Silicon has low absorption loss and high refractive index in the optical communication band, which is beneficial to reducing transmission loss. Therefore, a Si waveguide is integrated in the hybrid integrated optical amplification chip 1200, and the transmission loss is small, which is beneficial to increasing the optical coupling efficiency. In addition, the Si waveguide has a smaller bending radius than the InP waveguide, and the size is smaller when bent. Therefore, the Si waveguide can be presented in a bent state to return the first modulated light and the second modulated light output from the optical modulation chip 1100 back into the optical modulation chip 1100 through the bent Si waveguide. The InP / Si hybrid integrated optical amplification chip in the present disclosure can make full use of the gain characteristics of the InP-based SOA optical amplifier and the low-loss characteristics of the Si waveguide, and package them together in a hybrid integrated manner to obtain a hybrid integrated optical chip. The hybrid integrated optical chip includes a silicon substrate, and thus can be integrated with a Si waveguide to make full use of the characteristics of the Si waveguide such as low transmission loss and bendability. In the present disclosure, both the optical amplifier and the silicon-based waveguide are integrated in the same chip, so that the gain characteristics of the optical amplifier and the low transmission loss characteristics of the silicon-based waveguide can be simultaneously exerted.

[0132] Since the polarization states of the first modulated light and the second modulated light are different, and the SOA optical chip is a polarization state element, the SOA optical chip has polarization characteristics. The polarization characteristics refer to being sensitive to the polarization state of the input light and producing different gain effects on the gain of input light with different polarization states.

[0133] In order to amplify the first modulated light and the second modulated light separately, a first optical amplification unit and a second optical amplification unit are respectively formed in the hybrid integrated optical amplification chip 1200. The first modulated light is amplified by the first optical amplification unit, and the second modulated light is amplified by the second optical amplification unit.

[0134] In some embodiments, the first optical amplification unit respectively includes a first optical amplifier 1210 and a first optical waveguide 1230. The materials of the first optical amplifier 1210 and the first optical waveguide 1230 may be different.

[0135] Exemplarily, the first optical amplifier 1210 is a monolithic integrated InP-based SOA optical amplifier, that is, the first InP-based SOA optical amplifier 1200a in the above embodiment is integrated in the first optical amplification unit. The first optical amplifier 1210 has gain characteristics and polarization characteristics like the above monolithic integrated InP-based SOA optical amplifier.

[0136] Exemplarily, the first optical waveguide 1230 can be a silicon-based waveguide. The silicon-based waveguide has low transmission loss.

[0137] The first optical amplifier 1210 has a preset polarization state to optically amplify the first modulated light. Exemplarily, the first optical amplifier 1210 has the same or similar polarization state as the first modulated light. The first optical waveguide 1230 is in a bent posture. One end of the first optical waveguide 1230 faces the optical port of the optical modulation chip 1100 that outputs the first modulated light, and the other end faces the optical port of the optical modulation chip 1100 that receives the amplified first modulated light. The first modulated light amplified by the first optical amplifier 1210 returns to the inside of the optical modulation chip 1100 along the first optical waveguide 1230. Based on the low transmission loss characteristic of the silicon waveguide, using the first optical waveguide 1230 to transmit the first modulated light before and after amplification is beneficial to reducing the transmission loss. Based on the bendable characteristic of the silicon waveguide, the first optical waveguide 1230 can be used to transmit the first modulated light before and after amplification, thereby eliminating the mirrors 1700a and 1700b in the above embodiment, which is beneficial to increasing chip integration and increasing the optical path stability.

[0138] In some embodiments, the second optical amplification unit includes a second optical amplifier 1220 and a second optical waveguide 1250 respectively. The materials of the second optical amplifier 1220 and the second optical waveguide 1250 can be different.

[0139] Exemplarily, the second optical amplifier 1220 is a monolithic integrated InP-based SOA optical amplifier, that is, the second InP-based SOA optical amplifier 1200b in the above embodiment is integrated in the second optical amplification unit. The second optical amplifier 1220 has gain characteristics and polarization characteristics like the above monolithic integrated InP-based SOA optical amplifier.

[0140] Exemplarily, the second optical waveguide 1250 can be a silicon-based waveguide. The silicon-based waveguide has low transmission loss.

[0141] The second optical amplifier 1220 has a preset polarization state to optically amplify the second modulated light. Exemplarily, the second optical amplifier 1220 has the same or a similar polarization state as the second modulated light. Since the polarization states of the first modulated light and the second modulated light are different, the polarization states of the first optical amplifier 1210 and the second optical amplifier 1220 are different. The second optical waveguide 1250 presents a bent posture. One end of the second optical waveguide 1250 faces the optical port of the optical modulation chip 1100 that outputs the second modulated light, and the other end faces the optical port of the optical modulation chip 1100 that receives the amplified second modulated light. The second modulated light amplified by the second optical amplifier 1220 returns to the inside of the optical modulation chip 1100 along the second optical waveguide 1250. Based on the characteristic of low transmission loss of the silicon waveguide, using the second optical waveguide 1250 to transmit the second modulated light before and after amplification is beneficial to reducing the transmission loss. Based on the bendable characteristic of the silicon waveguide, the second optical waveguide 1250 can be used to transmit the second modulated light before and after amplification, thereby eliminating the mirrors 1700c and 1700d in the above embodiments, which is beneficial to increasing the chip integration and the optical path stability.

[0142] In the present disclosure, taking the optical modulation chip 1100 as a silicon optical chip as an example, the optical waveguide in the optical modulation chip 1100 is a silicon waveguide; the hybrid integrated optical amplifier chip 1200 integrates a silicon waveguide. The mode spots transmitted in the optical modulation chip 1100 and the hybrid integrated optical amplifier chip 1200 are both the mode spots transmitted by the silicon waveguide, and the mode fields can be matched. However, the mode spot size transmitted by the silicon waveguide is small, which is not conducive to the coupling between the optical modulation chip 1100 and the hybrid integrated optical amplifier chip 1200. Therefore, a mode spot converter is formed at the coupling optical port of the optical modulation chip 1100 to increase the mode spot size transmitted by the silicon waveguide in the optical modulation chip 1100; since the hybrid integrated optical amplifier chip 1200 has a silicon waveguide with a relatively high refractive index inside, a mode spot converter is also formed at its coupling optical port to increase the mode spot size transmitted by the silicon waveguide in the hybrid integrated optical amplifier chip 1200. Furthermore, the optical coupling efficiency between the optical modulation chip 1100 and the hybrid integrated optical amplifier chip 1200 is increased. For a monolithic integrated InP-based SOA optical amplifier, the waveguide inside it is an InP optical waveguide. Due to the material properties of the InP optical waveguide such as low refractive index, a mode spot converter with a relatively large mode spot size cannot be formed at the end face of the InP optical waveguide, thereby reducing the optical coupling efficiency between the optical modulation chip 1100 and the monolithic integrated InP-based SOA optical amplifier.

[0143] In the present disclosure, compared with a monolithic integrated InP-based SOA optical amplifier, since a silicon substrate is integrated in the hybrid integrated optical amplification chip 1200, a silicon waveguide and a mode converter with a relatively large size can be formed on the surface of the silicon substrate. Therefore, compared with a monolithic integrated InP-based SOA optical amplifier, the hybrid integrated optical amplification chip 1200 can integrate a mode converter to improve the optical coupling efficiency, and at the same time, the low transmission loss and bendable characteristics of the silicon waveguide can be utilized to reduce the transmission loss and eliminate the discrete mirrors arranged in free space.

[0144] In some embodiments, the optical modulation chip 1100 is provided with a first mode converter 1111 at the first optical port, a second mode converter 1112 at the second optical port, and a third mode converter 1113 at the third optical port to improve the optical coupling efficiency with the fiber array 1300. A mode converter is also provided at the coupling optical port between the optical modulation chip 1100 and the hybrid integrated optical amplification chip 1200. Exemplarily, the optical modulation chip 1100 forms a fourth mode converter 1114 at the fourth optical port, a fifth mode converter 1115 at the fifth optical port, a sixth mode converter 1116 at the sixth optical port, and a seventh mode converter 1117 at the seventh optical port. Among them, the fourth optical port, the fifth optical port, the sixth optical port, and the seventh optical port are arranged in sequence from top to bottom, and the fourth mode converter 1114, the fifth mode converter 1115, the sixth mode converter 1116, and the seventh mode converter 1117 are all located on the same side and are arranged in sequence from top to bottom. The "top" and "bottom" directions are Figure 7 the up-and-down relative directions in

[0145] The fourth optical port of the optical modulation chip 1100 is the optical port for outputting the first modulated light, the fifth optical port is the optical port for outputting the second modulated light, the sixth optical port is the optical port for inputting the amplified first modulated light, and the seventh optical port is the optical port for inputting the amplified second modulated light. That is, the first modulated light and the second modulated light are respectively output from the fourth optical port and the fifth optical port of the optical modulation chip 1100; the amplified first modulated light and the second modulated light are respectively input into the optical modulation chip 1100 from the sixth optical port and the seventh optical port.

[0146] In some embodiments, a first mode spot converter 1241 is formed at the first optical port of the hybrid integrated optical amplification chip 1200, a second mode spot converter 1242 is formed at the second optical port, a third mode spot converter 1243 is formed at the third optical port, and a fourth mode spot converter 1244 is formed at the fourth optical port. Among them, the first optical port, the second optical port, the third optical port, and the fourth optical port of the hybrid integrated optical amplification chip 1200 are arranged in sequence from top to bottom; the first mode spot converter 1241, the second mode spot converter 1242, the third mode spot converter 1243, and the fourth mode spot converter 1244 are all arranged on the same side of the hybrid integrated optical amplification chip 1200 and are arranged in sequence from top to bottom. The "up" and "down" directions are Figure 7 the up and down relative directions in Figure 7 . The first optical port and the second optical port of the hybrid integrated optical amplification chip 1200 are input optical ports, and the third optical port and the fourth optical port are output optical ports.

[0147] The first optical port of the hybrid integrated optical amplification chip 1200 is the optical port for inputting the first modulated light, the second optical port is the optical port for inputting the second modulated light, the third optical port is the optical port for outputting the amplified first modulated light, and the fourth optical port is the optical port for outputting the amplified second modulated light. That is, the first modulated light and the second modulated light output from the optical modulation chip 1100 enter the hybrid integrated optical amplification chip 1200 along the first optical port and the second optical port of the hybrid integrated optical amplification chip 1200 respectively; the first modulated light and the second modulated light amplified by the hybrid integrated optical amplification chip 1200 are output along the third optical port and the fourth optical port of the hybrid integrated optical amplification chip 1200 respectively, and are coupled into the optical modulation chip 1100 and multiplexed in the optical multiplexer.

[0148] In some embodiments, the fourth mode spot converter 1114, the fifth mode spot converter 1115, the sixth mode spot converter 1116, and the seventh mode spot converter 1117 of the optical modulation chip 1100 are respectively coupled to the first mode spot converter 1241, the second mode spot converter 1242, the third mode spot converter 1243, and the fourth mode spot converter 1244 of the hybrid integrated optical amplification chip 1200. The waveguide widths of the fourth mode spot converter 1114 and the first mode spot converter 1241 are symmetrically arranged. The waveguide width of the fourth mode spot converter 1114 gradually increases along the optical transmission direction, and the waveguide width of the first mode spot converter 1241 gradually increases along the optical transmission direction to achieve the largest mode spot size at the coupling interface, thereby increasing the optical coupling efficiency. The waveguide widths of the fifth mode spot converter 1115 and the second mode spot converter 1242 are set in the same way. The waveguide widths of the sixth mode spot converter 1116 and the third mode spot converter 1243 are set in the same way. The waveguide widths of the seventh mode spot converter 1117 and the fourth mode spot converter 1244 are set in the same way.

[0149] The first modulated light is sequentially transmitted into the hybrid integrated optical amplification chip 1200 along the fourth mode spot converter 1114 and the first mode spot converter 1241; the second modulated light is sequentially transmitted into the hybrid integrated optical amplification chip 1200 along the fifth mode spot converter 1115 and the second mode spot converter 1242; the first modulated light amplified by the first optical amplifier 1210 is sequentially returned to the optical modulation chip 1100 along the third mode spot converter 1243 and the sixth mode spot converter 1116; the second modulated light amplified by the second optical amplifier 1220 is sequentially returned to the optical modulation chip 1100 along the fourth mode spot converter 1244 and the seventh mode spot converter 1117, and multiplexing is performed in the optical multiplexer.

[0150] In the present disclosure, the first mode spot converter 1241 and the fourth mode spot converter 1244 of the hybrid integrated optical amplification chip 1200 are respectively located at both ends of the first optical waveguide 1230, and the first mode spot converter 1241 and the fourth mode spot converter 1244 are arranged to face the same end face of the optical modulation chip 1100 through the bending posture of the first optical waveguide 1230; the second mode spot converter 1242 and the third mode spot converter 1243 are respectively located at both ends of the second optical waveguide 1250, and the second mode spot converter 1242 and the third mode spot converter 1243 are arranged to face the same end face of the optical modulation chip 1100 through the bending posture of the second optical waveguide 1250.

[0151] In the present disclosure, the first modulated light output by the optical modulation chip 1100 enters the hybrid integrated optical amplification chip 1200 along the first mode spot converter 1241, is amplified by the first optical amplifier 1210, and the amplified first modulated light is transmitted along the first optical waveguide 1230 to the fourth mode spot converter 1244 and output, so that the amplified first modulated light returns to the optical modulation chip 1100. Therefore, the first optical amplification unit of the hybrid integrated optical amplification chip 1200 respectively includes the first mode spot converter 1241, the first optical amplifier 1210, the first optical waveguide 1230, and the fourth mode spot converter 1244. The first mode spot converter 1241 and the fourth mode spot converter 1244 are respectively located at both ends of the first optical waveguide 1230, and the first mode spot converter 1241 and the fourth mode spot converter 1244 face the same side through the bending of the first optical waveguide 1230.

[0152] The second modulated light output by the optical modulation chip 1100 enters the hybrid integrated optical amplification chip 1200 along the second mode spot converter 1242, is amplified by the second optical amplifier 1220, and the amplified second modulated light is transmitted along the second optical waveguide 1250 to the third mode spot converter 1243 and output, so that the amplified second modulated light returns to the optical modulation chip 1100. Therefore, the second optical amplification unit of the hybrid integrated optical amplification chip 1200 respectively includes a second mode spot converter 1242, a second optical amplifier 1220, a second optical waveguide 1250, and a third mode spot converter 1243. The second mode spot converter 1242 and the third mode spot converter 1243 are respectively located at both ends of the second optical waveguide 1250, and the bending of the second optical waveguide 1250 makes the second mode spot converter 1242 and the third mode spot converter 1243 face the same side.

[0153] The hybrid integrated optical amplification chip 1200 provided by the present disclosure is respectively integrated with a first optical amplification unit and a second optical amplification unit to amplify the first modulated light and the second modulated light respectively. The amplified first modulated light and second modulated light return to the optical modulation chip 1100 again and are combined in the built-in optical combiner 1140. In the present disclosure, since the polarization states of the first modulated light and the second modulated light are different, and the SOA optical amplifier is a polarization state element, therefore, the method of first amplifying the first modulated light and the second modulated light respectively and then combining them can ensure that both the first modulated light and the second modulated light are optically amplified, thereby improving the optical emission power compared with the method of optically amplifying after combining.

[0154] In the present disclosure, placing the optical combiner 1140 in the optical modulation chip 1100 can reduce the growth process difficulty of the hybrid integrated optical amplification chip 1200 compared with placing the optical combiner 1140 in the hybrid integrated optical amplification chip 1200. Placing the optical combiner 1140 in the optical modulation chip 1100 is a mature process, so the optical combiner 1140 is exemplarily placed in the optical modulation chip 1100.

[0155] As Figure 7 shown, when the hybrid integrated optical amplification chip 1200 is packaged in the optical module in the present disclosure, the hybrid integrated optical amplification chip 1200 and the optical modulation chip 1100 can be packaged by means of end face coupling. In some embodiments, refractive index matching glue can be used to achieve end face coupling between the end faces of the hybrid integrated optical amplification chip 1200 and the optical modulation chip 1100. The hybrid integrated optical amplification chip 1200 and the fiber array 1300 are arranged on the same side of the optical modulation chip 1100 to reasonably design the optical path. The specific packaging implementation method will be introduced in detail later.

[0156] Figure 8Another schematic diagram of the coupling structure between the hybrid integrated optical amplification chip and the optical modulation chip provided according to some embodiments of the present disclosure. As Figure 8 shown, in some embodiments, when the hybrid integrated optical amplification chip 1200 is packaged in the optical module in the present disclosure, the hybrid integrated optical amplification chip 1200 and the optical modulation chip 1100 can be packaged by means of the lens array 1500. Exemplarily, a lens array 1500 is provided between the hybrid integrated optical amplification chip 1200 and the optical modulation chip 1100, and the hybrid integrated optical amplification chip 1200 and the optical fiber array 1300 are arranged on the same side of the optical modulation chip 1100 to reasonably design the optical path. The specific packaging implementation manner will be introduced in the following.

[0157] Figure 9 A schematic diagram of the first optical amplification unit in the hybrid integrated optical amplification chip provided according to some embodiments of the present disclosure. As Figure 9 shown, in some embodiments, the hybrid integrated optical amplification chip 1200 includes a first optical amplification unit and a second optical amplification unit to respectively perform optical amplification on the first modulated light and the second modulated light output by the optical modulation chip 1100. The structures of the first optical amplification unit and the second optical amplification unit are the same, and each includes a first optical amplifier 1210 and a second optical amplifier 1220. The polarization states of the first optical amplifier 1210 and the second optical amplifier 1220 are different to respectively perform optical amplification on the first modulated light and the second modulated light.

[0158] The first optical amplification unit of the hybrid integrated optical amplification chip 1200 respectively includes a first mode spot converter 1241, a first optical amplifier 1210, a first optical waveguide 1230, and a fourth mode spot converter 1244. The first mode spot converter 1241 and the fourth mode spot converter 1244 are respectively located at both ends of the first optical waveguide 1230, and the first mode spot converter 1241 and the fourth mode spot converter 1244 both face the same side through the bending of the first optical waveguide 1230.

[0159] To ensure that the first modulated light can be transmitted into the first optical amplifier 1210, the first optical amplifier 1210 is arranged above the first optical waveguide 1230, and the silicon waveguide below the first optical amplifier 1210 is a disconnected silicon waveguide section to ensure that the first modulated light can be transmitted into the first optical amplifier 1210. Exemplarily, the first modulated light is vertically coupled upward along the first optical waveguide 1230 into the first optical amplifier 1210, optically amplified by the first optical amplifier 1210, and the amplified first modulated light is vertically coupled downward along the first optical amplifier 1210 into the first optical waveguide 1230, and continues to be transmitted to the fourth mode spot converter 1244 and output, so that the amplified first modulated light returns to the optical modulation chip 1100. It can be understood that the second optical amplification unit adopts the same structural design as the first optical amplification unit.

[0160] In the present disclosure, the first modulated light and the second modulated light are respectively output from an optical modulation chip and transmitted into a hybrid integrated optical amplification chip. The first optical amplifier and the second optical amplifier in the hybrid integrated optical amplification chip respectively perform optical amplification on the first modulated light and the second modulated light. Then, the amplified first modulated light returns to the optical modulation chip along the first optical waveguide and is multiplexed in an optical multiplexer. The amplified second modulated light returns to the optical modulation chip along the second optical waveguide and is multiplexed in the optical multiplexer. The multiplexed optical emission signal is output from the optical modulation chip and transmitted along an optical fiber array.

[0161] In the present disclosure, a first optical amplifier 1210 and a second optical amplifier 1220 are integrated in the hybrid integrated optical amplification chip 1200 to respectively perform optical amplification on the first modulated light and the second modulated light, thereby improving the optical amplification efficiency. A first optical waveguide 1230 and a second optical waveguide 1250 are integrated in the hybrid integrated optical amplification chip 1200 to respectively return the amplified first modulated light and the second modulated light to the optical modulation chip 1100. In the present disclosure, by integrating both the optical amplifier and the silicon-based waveguide in the same chip, the gain characteristic of the optical amplifier and the low transmission loss characteristic of the silicon-based waveguide can be utilized simultaneously. Meanwhile, by integrating both the optical amplification optical path and the return transmission optical path in the same chip, the stability of the optical path can be ensured. Meanwhile, by integrating each device in the same chip, the coupling efficiency with the optical modulation chip 1100 can be increased.

[0162] In some embodiments, the hybrid integrated optical amplification chip 1200 is an InP / Si hybrid integrated optical amplification chip. The substrate of the hybrid integrated optical amplification chip 1200 is a silicon substrate. The optical amplifier integrated in the hybrid integrated optical amplification chip 1200 is a monolithic integrated InP-based SOA optical amplifier. Exemplarily, the monolithic integrated InP-based SOA optical amplifier is inverted on the surface of the silicon substrate. The optical waveguide integrated in the hybrid integrated optical amplification chip 1200 is a Si-based waveguide. The mode converter integrated in the hybrid integrated optical amplification chip 1200 is a Si-based mode converter.

[0163] Figure 10 Schematic diagram of the assembly relationship between a circuit board and a substrate according to some embodiments of the present disclosure. As Figure 10 shown, a notch 302 is formed on the surface of the circuit board 300, and the substrate 900 is embedded in the notch 302, thereby fixing the substrate 900 on the surface of the circuit board 300. The substrate 900 functions as a heat sink. Exemplarily, the substrate 900 can be a tungsten copper substrate, which is beneficial for better heat dissipation. The surface of the substrate 900 also functions as a support. The bottom surface of the substrate 900 is exposed relative to the circuit board 300, and the bottom surface of the substrate 900 has a certain thickness to enhance the supporting effect of the substrate 900.

[0164] Exemplarily, an optical modulation chip 1100, a hybrid integrated optical amplification chip 1200, and an optical fiber array 1300 are respectively disposed on the upper surface of the substrate 900.

[0165] Figure 11 It is a packaging structure of an optical module provided according to some embodiments of the present disclosure Figure 1 ; Figure 12 It is a packaging structure of an optical module provided according to some embodiments of the present disclosure Figure 2 . As Figure 11 and Figure 12 shown, the optical modulation chip 1100 and the hybrid integrated optical amplification chip 1200 are coupled and connected by an end-face coupling method. Exemplarily, the optical modulation chip 1100 and the hybrid integrated optical amplification chip 1200 are end-face coupled by a refractive index matching glue to improve the optical coupling efficiency.

[0166] In some embodiments, the notch 302 of the circuit board 300 overlaps on the surface of the substrate 900, thereby realizing the fixed connection between the circuit board 300 and the substrate 900. The optical modulation chip 1100, the hybrid integrated optical amplification chip 1200, and the optical fiber array 1300 are all disposed on the surface of the substrate 900, and the hybrid integrated optical amplification chip 1200 and the optical fiber array 1300 are disposed on the same side of the optical modulation chip 1100. The surface of the substrate 900 sinks relative to the surface of the circuit board 300 so that the surface of the optical modulation chip 1100 is flush with the surface of the circuit board 300.

[0167] In some embodiments, the hybrid integrated optical amplification chip 1200 emits a large amount of heat during operation. For this reason, a heat sink 1400 is disposed on the surface of the hybrid integrated optical amplification chip 1200. Exemplarily, since the upper housing 201 of the optical module has a good heat dissipation channel, the heat sink 1400 is thermally connected to the upper housing 201 of the optical module, so that the heat generated by the hybrid integrated optical amplification chip 1200 is conducted upward along the heat sink 1400 to the upper housing 201 of the optical module and then dissipated, ensuring the normal operation of the hybrid integrated optical amplification chip 1200.

[0168] Figure 13 It is another packaging structure of an optical module provided according to some embodiments of the present disclosure Figure 1 ; Figure 14 It is another packaging structure of an optical module provided according to some embodiments of the present disclosure Figure 2 ; Figure 15 It is another packaging structure of an optical module provided according to some embodiments of the present disclosure Figure 3 . As Figures 13 - 15As shown, the optical modulation chip 1100 and the hybrid integrated optical amplification chip 1200 are coupled and connected by means of a lens array. Exemplarily, a lens array 1500 is provided between the optical modulation chip 1100 and the hybrid integrated optical amplification chip 1200, and the coupling between the optical modulation chip 1100 and the hybrid integrated optical amplification chip 1200 is achieved through the lens array 1500.

[0169] In some embodiments, similarly, the notch 302 of the circuit board 300 is lapped on the surface of the substrate 900, so as to realize the fixed connection between the circuit board 300 and the substrate 900. The optical modulation chip 1100, the hybrid integrated optical amplification chip 1200, the fiber optic array 1300, and the lens array 1500 are all disposed on the surface of the substrate 900, and the hybrid integrated optical amplification chip 1200, the fiber optic array 1300, and the lens array 1500 are all located on the same side of the optical modulation chip 1100. The surface of the substrate 900 sinks relative to the surface of the circuit board 300, so that the surface of the optical modulation chip 1100 is flush with the surface of the circuit board 300.

[0170] In some embodiments, in order to conduct the heat generated by the hybrid integrated optical amplification chip 1200 during operation, a TEC 1600 is provided on the surface of the substrate 900, and the hybrid integrated optical amplification chip 1200 is placed on the surface of the TEC 1600. The heat generated by the hybrid integrated optical amplification chip 1200 is conducted out through the cold surface of the TEC 1600 to ensure the normal operation of the hybrid integrated optical amplification chip 1200.

[0171] Exemplarily, the hybrid integrated optical amplification chip 1200 is pre-pasted on the surface of the TEC 1600 with optical glue. Since the hybrid integrated optical amplification chip 1200 and the TEC 1600 are fixed together at this time, it is not suitable to perform end-face coupling with the optical modulation chip 1100 anymore. Therefore, the coupling between the optical modulation chip 1100 and the hybrid integrated optical amplification chip 1200 is achieved through the lens array 1500.

[0172] Figure 16 It is a packaging structure diagram for end-face coupling between an optical modulation chip and a hybrid integrated optical amplification chip provided according to some embodiments of the present disclosure; Figure 17 It is an exploded view of the packaging for end-face coupling between an optical modulation chip and a hybrid integrated optical amplification chip provided according to some embodiments of the present disclosure. As Figure 16 and Figure 17As shown, in some embodiments, a notch 302 is formed on the surface of the circuit board 300. A bearing surface 910 and a lapping surface 920 are respectively formed on the surface of the substrate 900. The lapping surface 920 is disposed around the bearing surface 910, and a height difference is formed between the bearing surface 910 and the lapping surface 920, which can be used to support the circuit board 300. Exemplarily, the surface of the lapping surface 920 is lower than the surface of the bearing surface 910. Exemplarily, the periphery of the notch 302 lapps on the surface of the lapping surface 920, thereby realizing the fixation of the circuit board 300 and the substrate 900.

[0173] The optical modulation chip 1100, the hybrid integrated optical amplification chip 1200, and the fiber array 1300 are respectively disposed on the surface of the bearing surface 910. Since the surface of the lapping surface 920 is lower than the surface of the bearing surface 910, the surfaces of the optical modulation chip 1100, the hybrid integrated optical amplification chip 1200, and the fiber array 1300 can be flush with the surface of the circuit board 300.

[0174] In some embodiments, a heat sink 1400 is provided on the surface of the hybrid integrated optical amplification chip 1200. Exemplarily, the heat sink 1400 is provided on the top surface of the hybrid integrated optical amplification chip 1200. The heat generated by the hybrid integrated optical amplification chip 1200 is conducted upward along the heat sink 1400 to the upper housing 201 of the optical module and then conducted out through heat conduction connection between the heat sink 1400 and the upper housing 201 of the optical module, ensuring the normal operation of the hybrid integrated optical amplification chip 1200.

[0175] Figure 18 It is an exploded view of the package of lens coupling between an optical modulation chip and a hybrid integrated optical amplification chip provided according to some embodiments of the present disclosure; Figure 19 It is a package structure diagram between a substrate, an optical modulation chip, and a hybrid integrated optical amplification chip provided according to some embodiments of the present disclosure; Figure 20 It is an exploded view of the package between a substrate, an optical modulation chip, and a hybrid integrated optical amplification chip provided according to some embodiments of the present disclosure. As Figures 18 - 20As shown, a notch 302 is formed on the surface of the circuit board 300. A bearing surface 910, a lapping surface 920, and a recessed surface 930 are respectively formed on the surface of the substrate 900. Among them, the surface of the lapping surface 920 is lower than the surface of the bearing surface 910. Exemplarily, the periphery of the notch 302 laps on the surface of the lapping surface 920, thereby realizing the fixation of the circuit board 300 and the substrate 900. The surface of the bearing surface 910 is respectively provided with an optical modulation chip 1100, an optical fiber array 1300, and a lens array 1500. When the hybrid integrated optical amplification chip 1200 is disposed on the surface of the TEC 1600, the recessed surface 930 is used to dispose the TEC 1600. Exemplarily, the TEC 1600 is disposed in the recessed surface 930, and then the hybrid integrated optical amplification chip 1200 is disposed on the surface of the TEC 1600. Since the TEC 1600 has a certain height, by disposing the TEC 1600 in the recessed surface 930, the TEC 1600 is sunk, so as to ensure that the hybrid integrated optical amplification chip 1200 located on the surface of the TEC 1600 is flush with the surface of the circuit board 300, ensuring shorter wire bonding.

[0176] In some embodiments, the optical fiber array 1300 and the lens array 1500 are respectively located at different orientations on the same cross-section of the optical modulation chip 1100. The hybrid integrated optical amplification chip 1200 is disposed on the transmission optical path of the lens array 1500.

[0177] Figure 21 It is a top view of the package for end-face coupling between an optical modulation chip and a hybrid integrated optical amplification chip provided according to some embodiments of the present disclosure. As Figure 21 shown, in some embodiments, the optical modulation chip 1100, the hybrid integrated optical amplification chip 1200, and the optical fiber array 1300 are respectively disposed on the surface of the substrate 900. The hybrid integrated optical amplification chip 1200 and the optical fiber array 1300 are disposed on the same side of the optical modulation chip 1100.

[0178] The hybrid integrated optical amplification chip 1200 and the optical modulation chip 1100 are coupled through end-face coupling; the optical fiber array 1300 and the optical modulation chip 1100 are also connected through end-face coupling.

[0179] Figure 22 It is a top view of the package for lens coupling between an optical modulation chip and a hybrid integrated optical amplification chip provided according to some embodiments of the present disclosure. As Figure22 shown, in some embodiments, the optical modulation chip 1100, the hybrid integrated optical amplification chip 1200, the optical fiber array 1300, and the lens array 1500 are respectively disposed on the surface of the substrate 900. The hybrid integrated optical amplification chip 1200, the optical fiber array 1300, and the lens array 1500 are disposed on the same side of the optical modulation chip 1100.

[0180] The hybrid integrated optical amplification chip 1200 and the optical modulation chip 1100 are coupled through a lens array 1500; the fiber array 1300 and the optical modulation chip 1100 are connected through end-face coupling.

[0181] Figure 23 It is a schematic optical path diagram corresponding to a coupling method between an optical modulation chip and a hybrid integrated optical amplification chip in an optical module provided according to some embodiments of the present disclosure. As Figure 23 shown, the optical modulation chip 1100 and the hybrid integrated optical amplification chip 1200 are coupled and connected through end-face coupling; the fiber array 1300 and the optical modulation chip 1100 are also connected through end-face coupling.

[0182] The light emitted by the light source is light that does not carry data. This light that does not carry data is transmitted through the second optical fiber ribbon 1312 of the fiber array 1300 into the optical modulation chip 1100. The optical splitter built in the optical modulation chip 1100 divides it into a certain proportion of first split light and second split light. The first split light is used as the light to be modulated and is transmitted into the optical modulator 1130 for modulation, and the second split light is used as the local oscillator light and is transmitted into the optical demodulator 1120 for demodulation. Among them, the first split light is transmitted into the optical modulator 1130, and the optical modulator 1130 modulates the first split light and outputs the first modulated light and the second modulated light respectively. The first modulated light and the second modulated light are respectively coupled and transmitted into the hybrid integrated optical amplification chip 1200 along the first optical port and the second optical port of the optical modulation chip 1100, and are respectively optically amplified by the first optical amplifier 1210 and the second optical amplifier 1220. The first modulated light amplified by the first optical amplifier 1210 returns to the optical modulation chip 1100 along the first optical waveguide and the third optical port of the optical modulation chip 1100; the second modulated light amplified by the second optical amplifier 1220 returns to the optical modulation chip 1100 along the second optical waveguide and the fourth optical port of the optical modulation chip 1100. And they are combined by the optical combiner 1140 built in the optical modulation chip 1100, and then transmitted out through the first optical fiber ribbon 1311 of the fiber array 1300.

[0183] The optical signal from the outside is transmitted through the third optical fiber ribbon 1313 of the fiber array 1300 into the optical demodulator 1120 built in the optical modulation chip 1100, and is coherently demodulated together with the second split light.

[0184] Figure 24 It is a schematic optical path diagram corresponding to another coupling method between an optical modulation chip and a hybrid integrated optical amplification chip in an optical module provided according to some embodiments of the present disclosure. As Figure 24 shown, the optical modulation chip 1100 and the hybrid integrated optical amplification chip 1200 are coupled and connected through the lens array 1500; the fiber array 1300 and the optical modulation chip 1100 are also connected through end-face coupling.

[0185] The light emitted by the light source is light that does not carry data. This light that does not carry data is transmitted through the second optical fiber band 1312 of the optical fiber array 1300 into the optical modulation chip 1100. The optical splitter built into the optical modulation chip 1100 divides it into a certain proportion of the first split light and the second split light. The first split light is transmitted as the light to be modulated into the optical modulator 1130 for modulation, and the second split light is transmitted as the local oscillator light into the optical demodulator 1120 for demodulation. Among them, the first split light is transmitted into the optical modulator 1130, and the optical modulator 1130 modulates the first split light and outputs the first modulated light and the second modulated light respectively. The first modulated light and the second modulated light are respectively output along the first optical port and the second optical port of the optical modulation chip 1100, and are coupled and transmitted through the lens array 1500 into the hybrid integrated optical amplification chip 1200, and are respectively optically amplified by the first optical amplifier 1210 and the second optical amplifier 1220. The first modulated light amplified by the first optical amplifier 1210 is output along the first optical waveguide, and is coupled through the lens array 1500 into the optical modulation chip 1100, and returns to the optical modulation chip 1100 through the third optical port of the optical modulation chip 1100; the second modulated light amplified by the second optical amplifier 1220 is output along the second optical waveguide, and is coupled through the lens array 1500 into the optical modulation chip 1100, and returns to the optical modulation chip 1100 through the fourth optical port of the optical modulation chip 1100. And they are combined by the optical combiner 1140 built into the optical modulation chip 1100, and then transmitted out through the first optical fiber band 1311 of the optical fiber array 1300.

[0186] The optical signal from the outside is transmitted through the third optical fiber band 1313 of the optical fiber array 1300 into the optical demodulator 1120 built into the optical modulation chip 1100, and performs coherent demodulation of the optical signal together with the second split light.

[0187] As described above, it is only the specific implementation manner of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present disclosure, thinking of changes or substitutions, should be covered within the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the protection scope of the claimed rights.

Claims

1. An optical module, characterized in that, Comprising: A circuit board with a notch on its surface; A substrate connected to the circuit board through the notch; An optical fiber array disposed on the surface of the substrate for transmitting the optical signal to be modulated and the combined modulated optical signal; An optical modulation chip disposed on the surface of the substrate and coupled to the optical fiber array, for receiving the optical signal to be modulated output by the optical fiber array. An optical modulator and an optical multiplexer are integrated in the optical modulation chip. The optical modulator is used to modulate the optical signal to be modulated and output a first modulated optical signal and a second modulated optical signal respectively, and the polarization states of the first modulated optical signal and the second modulated optical signal are different; A hybrid integrated optical amplification chip disposed on the surface of the substrate and coupled to the optical modulation chip. A first optical amplifier, a second optical amplifier, a first optical waveguide optically connected to the first optical amplifier, and a second optical waveguide optically connected to the second optical amplifier are integrated in the hybrid integrated optical amplification chip. Wherein, both the first optical amplifier and the second optical amplifier are polarization state devices. The first optical amplifier has a first preset polarization state to optically amplify the first modulated optical signal output by the optical modulation chip, and the second optical amplifier has a second preset polarization state to optically amplify the second modulated optical signal output by the optical modulation chip; The first optical waveguide is used to return the amplified first modulated optical signal to the optical modulation chip and access it to the optical multiplexer, and the second optical waveguide is used to return the amplified second modulated optical signal to the optical modulation chip and access it to the optical multiplexer. The amplified first modulated optical signal and the amplified second modulated optical signal are multiplexed in the optical multiplexer.

2. The optical module according to claim 1, wherein The optical fiber array and the hybrid integrated optical amplification chip are respectively disposed on the same side of the optical modulation chip; The optical fiber array and the hybrid integrated optical amplification chip are respectively connected to the optical modulation chip through end-face coupling.

3. The optical module according to claim 1, characterized in that The optical fiber array and the hybrid integrated optical amplification chip are respectively disposed on the same side of the optical modulation chip; The optical fiber array and the optical modulation chip are coupled through end-face coupling; A semiconductor refrigerator is disposed on the surface of the substrate, the hybrid integrated optical amplification chip is disposed on the surface of the semiconductor refrigerator, and the hybrid integrated optical amplification chip and the optical modulation chip are coupled through a lens.

4. The optical module according to claim 1, characterized in that, A mode field converter is formed at the optical port of the optical modulation chip, and a mode field converter corresponding to the mode field converter at the optical port of the optical modulation chip is formed at the optical port of the hybrid integrated optical amplification chip.

5. The optical module according to claim 1, wherein The hybrid integrated optical amplification chip includes a first optical amplification unit and a second optical amplification unit; The first optical amplification unit is used to receive the first modulated optical signal, optically amplify the first modulated optical signal and then return it to the optical modulation chip for multiplexing; the second optical amplification unit is used to receive the second modulated optical signal, optically amplify the second modulated optical signal and then return it to the optical modulation chip for multiplexing; One end of the first optical amplification unit is coupled to the output optical port of the optical modulation chip, and the other end is coupled to the input optical port of the optical modulation chip; One end of the second optical amplification unit is coupled to the output optical port of the optical modulation chip, and the other end is coupled to the input optical port of the optical modulation chip; The first optical amplification unit respectively includes the first optical waveguide and the first optical amplifier disposed above the first optical waveguide. Wherein, mode field converters are respectively connected to both ends of the first optical waveguide; the materials of the first optical waveguide and the first optical amplifier are different; The second optical amplification unit respectively includes the second optical waveguide and the second optical amplifier disposed above the second optical waveguide. Wherein, mode field converters are respectively connected to both ends of the second optical waveguide; the materials of the second optical waveguide and the second optical amplifier are different.

6. A hybrid integrated optical amplification chip, characterized in that, Comprising: A first optical amplification unit, respectively including a first optical waveguide, a first optical amplifier disposed above the first optical waveguide, a first mode field converter disposed at one end of the first optical waveguide, and a second mode field converter disposed at the other end of the first optical waveguide; A second optical amplification unit, respectively including a second optical waveguide, a second optical amplifier disposed above the second optical waveguide, a third mode field converter disposed at one end of the second optical waveguide, and a fourth mode field converter disposed at the other end of the second optical waveguide.

7. The hybrid integrated optical amplification chip according to claim 6, wherein, The first optical amplifier is an InP-based optical amplifier, and the second optical amplifier is an InP-based optical amplifier; The first optical waveguide is a silicon-based optical waveguide, and the second optical waveguide is a silicon-based optical waveguide.

8. The hybrid integrated optical amplification chip according to claim 6, characterized in that The first optical amplifier and the second optical amplifier have different polarization states.

9. The hybrid integrated optical amplification chip according to claim 6, wherein The first mode field converter, the second mode field converter, the third mode field converter, and the fourth mode field converter are respectively arranged on the same side of the hybrid integrated optical amplification chip.

10. The hybrid integrated optical amplification chip according to claim 6, characterized in that, The hybrid integrated optical amplification chip is an InP / Si hybrid integrated optical amplification chip.

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