Fiber amplifier, optical transmitting module, optical receiving module, and related device

Abstract

A fiber amplifier, an optical transmitting module (902), and an optical receiving module (1002). The fiber amplifier comprises a photonic integrated chip (210, 310, 710, 810), a pump laser (215, 315, 716, 822), and a gain medium (216, 316, 717, 823). The photonic integrated chip (210, 310, 710, 810) comprises a multiplexing module (212, 312, 713, 812). The multiplexing module (212, 312, 713, 812) is connected to a first port of the photonic integrated chip (210, 310, 710, 810) by means of a first optical waveguide (241, 741) of the photonic integrated chip (210, 310, 710, 810). The multiplexing module (212, 312, 713, 812) is connected to a second port of the photonic integrated chip (210, 310, 710, 810) by means of a second optical waveguide (242, 743) of the photonic integrated chip (210, 310, 710, 810). The second port is connected to the pump laser (215, 315, 716, 822). The multiplexing module (212, 312, 713, 812) is connected to a third port of the photonic integrated chip (210, 310, 710, 810) by means of a third optical waveguide (243, 744) of the photonic integrated chip (210, 310, 710, 810). The third port is connected to the gain medium (216, 316, 717, 823).

Description

Optical fiber amplifier, optical transmitting module, optical receiving module and related equipment

[0001] The present application claims priority to the Chinese patent application No. 202510038538.X, filed on January 9, 2025, and entitled "Optical fiber amplifier, optical transmitting module, optical receiving module and related equipment", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the field of optical communication technology, and in particular to an optical fiber amplifier, an optical transmitting module, an optical receiving module and related equipment. BACKGROUND

[0003] An erbium-doped fiber amplifier (EDFA) is a core device in an optical communication network, which is used for optical signal amplification. FIG. 1 is a structural diagram of an existing erbium-doped fiber amplifier. The EDFA includes a wavelength division multiplexer (WDM) 102, an erbium-doped fiber (EDF) 103, and a pump laser 104. The erbium-doped fiber 103 serves as a gain medium of the EDFA, the WDM 102 combines the pump light from the pump laser 104 and the optical signal to be amplified into the erbium-doped fiber 103, and the erbium ions in the erbium-doped fiber 103 achieve particle number inversion under the action of the pump light, thereby producing stimulated radiation light amplification for the optical signal within a specific wavelength range incident to the erbium-doped fiber 103.

[0004] The EDFA can also include some other devices, for example, an input optical fiber 100 for inputting the optical signal to the EDFA, a first isolator (ISO) 101 and a second ISO 105 for preventing reflected light from entering the erbium-doped fiber 103, a variable optical attenuator (VOA) 106 for realizing optical power adjustment, a filter 107, a light splitter 108, an output optical fiber 110, and a monitor photodiode (mPD) 109 for realizing optical power detection, and other devices.

[0005] However, the components included in the EDFA are in a discrete state, and the number of components included in the EDFA in the discrete state is large, the independent packaging of each discrete component occupies a certain volume, thereby making the volume of the entire EDFA large, and the material consumed by the packaging of the EDFA is large. Moreover, the single component includes a working unit and a fiber collimator, the working unit is aligned with the fiber collimator through a free-space optical path, and the fiber collimator is aligned with the optical fiber connected to the component, so that the single component is very sensitive to the optical path alignment accuracy and dirt, and is easy to cause the failure of optical signal transmission. SUMMARY

[0006] Embodiments of the present application provide an optical fiber amplifier, an optical transmitting module, an optical receiving module and related devices, which are used to improve the integration of the optical fiber amplifier, reduce the space volume occupied by the optical fiber amplifier, and improve the reliability and large-scale production capacity of the optical fiber amplifier.

[0007] In a first aspect, an embodiment of the present application provides an optical fiber amplifier, comprising a photonic integrated chip, a pump laser and a gain medium, the photonic integrated chip comprising a multiplexing module, the multiplexing module being connected to a first port of the photonic integrated chip through a first optical waveguide of the photonic integrated chip, the multiplexing module being connected to a second port of the photonic integrated chip through a second optical waveguide of the photonic integrated chip, the second port being connected to the pump laser, the multiplexing module being connected to a third port of the photonic integrated chip through a third optical waveguide of the photonic integrated chip, the third port being connected to the gain medium; the multiplexing module is configured to receive a first optical signal from the first port and receive pump light from the pump laser, and combine the first optical signal and the pump light to obtain a second optical signal, and the multiplexing module is further configured to transmit the second optical signal to the gain medium, and the gain medium is configured to amplify the optical power of the first optical signal based on the pump light to obtain a third optical signal.

[0008] According to the present aspect, the optical fiber amplifier integrates the multiplexing module and each port by using the photonic integrated chip, thereby improving the integration of the optical fiber amplifier, reducing the space volume occupied by the optical fiber amplifier, improving the reliability, and making the optical fiber amplifier have the characteristics of large-scale production and high yield. The multiplexing module included in the photonic integrated chip directly combines the pump light and the first optical signal through the optical waveguide of the photonic integrated chip. Since the stability and airtightness of the optical waveguide are good, compared with the combination scheme based on free-space optical coupling, the degradation of the optical signal caused by the displacement of the optical path or dirt is avoided, thereby improving the reliability of the optical signal transmission, reducing the sensitivity to the optical path alignment accuracy and dirt, and inhibiting or avoiding the failure of the optical signal transmission. Since the photonic integrated chip, which is a core component of the optical fiber amplifier, is manufactured by using a mature semiconductor process, the large-scale production capacity of the optical fiber amplifier is also improved.

[0009] In an optional implementation of the first aspect, the photonic integrated chip further comprises a fourth port and a tunable optical attenuator, the tunable optical attenuator is connected to the fourth port through the optical waveguide of the photonic integrated chip, the fourth port is connected to the gain medium, the gain medium is configured to transmit the third optical signal to the tunable optical attenuator through the fourth port, and the tunable optical attenuator is configured to adjust the optical power of the third optical signal.

[0010] With the implementation, the photonic integrated chip at least integrates the multiplexing module, the tunable optical attenuator, and the ports, thereby reducing the number of devices in a discrete state included in the fiber amplifier, effectively reducing the fusion fiber points and the disc fiber length between devices on the whole fiber amplifier, improving the manufacturability of the fiber amplifier, improving the integration of the fiber amplifier, reducing the space volume occupied by the fiber amplifier, and improving the reliability.

[0011] In an optional implementation of the first aspect, the photonic integrated chip further comprises a fourth, an optical splitter, a fifth port, and a monitoring optical detector, the optical splitter is connected to the fourth port, the fifth port, and the monitoring optical detector through the optical waveguide of the photonic integrated chip, the fourth port is connected to the fourth port, the fifth port, and the monitoring optical detector, the fourth port is connected to the gain medium; the gain medium is configured to transmit the third optical signal to the optical splitter through the fourth port, and split the third optical signal to obtain monitoring light and output light, the optical splitter is further configured to transmit the monitoring light and the output light to the monitoring optical detector and the fifth port, respectively, and the monitoring optical detector is configured to detect the optical power of the output light according to the monitoring light.

[0012] With the implementation, the photonic integrated chip at least integrates the multiplexing module, an optical splitter, a monitoring optical detector, and ports, thereby reducing the number of devices in a discrete state included in the fiber amplifier, effectively reduces the fusion fiber points and the disc fiber length between devices on the whole fiber amplifier, improves the manufacturability of the fiber amplifier, improves the integration of the fiber amplifier, reduces the space volume occupied by the fiber amplifier, and improves the reliability.

[0013] In an optional implementation of the first aspect, the photonic integrated chip further comprises a fourth and a filter module, the filter module is connected to the fourth port through the optical waveguide of the photonic integrated chip, the filter module is connected to the fourth port, the fourth port is connected to the gain medium, the gain medium is configured to transmit the fourth optical signal to the filter module through the fourth port, and the filter module is configured to filter the third optical signal.

[0014] With the implementation, the photonic integrated chip integrates at least the multiplexing module, the filtering module and the ports, reduces the number of devices in a discrete state included in the fiber amplifier, effectively reduces the fusion fiber points and the disc fiber length between the devices of the fiber amplifier as a whole, improves the manufacturability of the fiber amplifier, improves the integration of the fiber amplifier, reduces the space volume occupied by the fiber amplifier, and improves the reliability.

[0015] Based on the first aspect, in an optional implementation, the filtering module includes at least one filter, and the filter is a tunable optical filter (TOF) or a gain-flattened filter (GFF).

[0016] With the implementation, the filtering module realizes different filtering modes for the third optical signal through different types of included filters. For example, if the filter is a tunable optical filter, the out-of-band noise in the third optical signal can be effectively filtered out, the signal-to-noise ratio of the fiber amplifier is improved, the signal quality of the output optical signal of the fiber amplifier is improved, the bit error rate of the output optical signal of the fiber amplifier reaching the receiving end is reduced, and thus the communication efficiency is improved. For another example, if the filter is a gain-flattened filter, the optical power of each wavelength included in the filtered optical signal is in a balanced state.

[0017] Based on the first aspect, in an optional implementation, the photonic integrated chip includes a substrate, and in a direction perpendicular to a surface of the substrate, the photonic integrated chip includes a first waveguide layer and a second waveguide layer arranged in sequence, the second waveguide layer forms the second port, the third port and the multiplexing module, and the photonic integrated chip further includes a cladding layer covering the first waveguide layer and the second waveguide layer.

[0018] With the implementation, each device included in the photonic integrated chip is formed in the first waveguide layer and the second waveguide layer, and the first waveguide layer and the second waveguide layer are tightly covered by the cladding layer. Therefore, the transmission of optical signals between the devices included in the photonic integrated chip is not through free space, and thus the photonic integrated chip is not sensitive to dirt. In other words, the dirt condition does not affect the transmission of optical signals between the devices included in the photonic integrated chip, and the failure rate of the fiber amplifier in transmitting optical signals is reduced.

[0019] Based on the first aspect, in an optional implementation, in a direction perpendicular to the surface of the substrate, the second waveguide layer, the first waveguide layer and the substrate are arranged in sequence.

[0020] By adopting this implementation method, the photonic integrated chip includes multiple waveguide layers to form multiple devices, which reduces the number of discrete devices in the fiber amplifier. This effectively reduces the splicing points and coil lengths between devices in the fiber amplifier as a whole, improves the manufacturability of the fiber amplifier, increases the integration of the fiber amplifier, reduces the space occupied by the fiber amplifier, and improves the reliability.

[0021] Based on the first aspect, in one optional implementation, a detector layer is included between the first waveguide layer and the second waveguide layer in a direction perpendicular to the substrate surface; or, the detector layer is included between the first waveguide layer and the substrate in a direction perpendicular to the substrate surface, the detector layer forming a monitoring photodetector, the monitoring photodetector being used to detect the output optical power of the fiber amplifier.

[0022] By adopting this implementation method, the photonic integrated chip integrates multiple devices, reducing the number of discrete devices included in the fiber amplifier. This effectively reduces the splicing points and coil lengths between devices in the fiber amplifier as a whole, improving the manufacturability, integration, and space occupied by the fiber amplifier, and enhancing reliability.

[0023] Based on the first aspect, in one optional implementation, the first waveguide layer, the second waveguide layer, and the substrate are arranged sequentially along a direction perpendicular to the surface of the substrate.

[0024] By adopting this implementation method, the photonic integrated chip includes multiple waveguide layers to form multiple devices, which reduces the number of discrete devices in the fiber amplifier. This effectively reduces the splicing points and coil lengths between devices in the fiber amplifier as a whole, improves the manufacturability of the fiber amplifier, increases the integration of the fiber amplifier, reduces the space occupied by the fiber amplifier, and improves the reliability.

[0025] Based on the first aspect, in one optional implementation, the photonic integrated chip further includes a detector layer, and the detector layer, the first waveguide layer, the second waveguide layer and the substrate are arranged sequentially along a direction perpendicular to the surface of the substrate, the detector layer forming a monitoring photodetector, the monitoring photodetector being used to detect the output optical power of the fiber amplifier.

[0026] By adopting this implementation method, the photonic integrated chip integrates multiple devices, reducing the number of discrete devices included in the fiber amplifier. This effectively reduces the splicing points and coil lengths between devices in the fiber amplifier as a whole, improving the manufacturability, integration, and space occupied by the fiber amplifier, and enhancing reliability.

[0027] In an optional implementation of the first aspect, the first waveguide layer forms the filtering module, the tunable optical attenuator, the optical splitter, and the first port, or a part of the filtering module, the tunable optical attenuator, the optical splitter, and the first port is formed by the first waveguide layer, and another part is formed by the second waveguide layer.

[0028] With the implementation, the photonic integrated chip integrates multiple devices, reduces the number of devices in a discrete state included in the fiber amplifier, improves the integration of the fiber amplifier, reduces the space volume occupied by the fiber amplifier, and improves the reliability.

[0029] In an optional implementation of the first aspect, the photonic integrated chip includes a substrate, a cladding layer, and a detector layer. A surface of the substrate includes a waveguide layer. The waveguide layer forms the multiplexing module, the first port, the second port, and the third port. The cladding layer covers the waveguide layer. A surface of the cladding layer includes the detector layer. The detector layer forms a monitoring light detector. The monitoring light detector is configured to detect output optical power of the fiber amplifier. The monitoring light detector is bonded to a surface of the photonic integrated chip.

[0030] With the implementation, each device included in the photonic integrated chip is formed in the first waveguide layer and the second waveguide layer. The first waveguide layer and the second waveguide layer are tightly covered by the cladding layer. The transmission of optical signals between the devices included in the photonic integrated chip is not through free space. Therefore, the photonic integrated chip is not sensitive to dirt. In other words, dirt does not affect the transmission of optical signals between the devices included in the photonic integrated chip. The failure rate of the fiber amplifier in transmitting optical signals is reduced.

[0031] In an optional implementation of the first aspect, the cladding layer further includes a coupling module between the detector layer and the waveguide layer. The coupling module is configured to couple monitoring light from the waveguide layer to the monitoring light detector. The monitoring light detector is configured to detect output optical power of the fiber amplifier based on the monitoring light.

[0032] With the implementation, the coupling module effectively improves the efficiency of coupling monitoring light to the monitoring light detector, reduces the loss in the coupling process of the monitoring light, and improves the accuracy of the monitoring light detector in detecting the output optical power of the fiber amplifier.

[0033] In an optional implementation of the first aspect, the first port, the second port, and the third port are edge couplers.

[0034] According to the implementation, the photonic integrated chip includes edge couplers as the ports, so that the coupling efficiency between the photonic integrated chip and devices (e.g., a pump laser, or a gain medium) outside the photonic integrated chip is improved, and the loss in the coupling process is reduced.

[0035] In a second aspect, the embodiments of the present application provide an optical transmitting module, comprising a light source, a photonic integrated chip, a pump laser and a gain medium, the photonic integrated chip comprising an optical modulator and a multiplexing module, the optical modulator being connected to a first port of the photonic integrated chip through a first optical waveguide of the photonic integrated chip, the optical modulator being connected to the multiplexing module through a second optical waveguide of the photonic integrated chip, the multiplexing module being connected to a second port of the photonic integrated chip through a third optical waveguide of the photonic integrated chip, the second port being connected to the pump laser, the multiplexing module being connected to a third port of the photonic integrated chip through a fourth optical waveguide of the photonic integrated chip, the third port being connected to the gain medium; the optical modulator is configured to modulate a first optical signal from the first port to obtain a modulated optical signal, and transmit the modulated optical signal to the multiplexing module, the multiplexing module is configured to receive pump light from the pump laser, and combine the modulated optical signal and the pump light to obtain a second optical signal, the multiplexing module is further configured to transmit the second optical signal to the gain medium, and the gain medium is configured to amplify the optical power of the first optical signal based on the pump light to obtain a third optical signal. The beneficial effects of the present aspect are described in the first aspect, and will not be repeated here.

[0036] In a third aspect, the embodiments of the present application provide an optical transmitter, comprising a processor, a driver and an optical transmitting module as described in the second aspect, the processor, the driver and the optical modulator being connected in sequence, the processor is configured to send an electrical signal to the driver, the driver is configured to transmit the amplified electrical signal to the optical modulator, the light source is configured to transmit a first optical signal to the optical modulator, and the optical modulator is configured to modulate the amplified electrical signal on the first optical signal to obtain the modulated optical signal.

[0037] In a fourth aspect, an embodiment of the present application provides an optical receiving module, comprising a photonic integrated chip, a pump laser and a gain medium, the photonic integrated chip comprising a multiplexing module and a detector, the multiplexing module being connected to a first port of the photonic integrated chip through a first optical waveguide of the photonic integrated chip, the multiplexing module being connected to a second port of the photonic integrated chip through a second optical waveguide of the photonic integrated chip, the second port being connected to the pump laser, the multiplexing module being connected to a third port of the photonic integrated chip through a third optical waveguide of the photonic integrated chip, the third port being connected to the gain medium, the detector being connected to a fourth port of the photonic integrated chip through a fourth optical waveguide of the photonic integrated chip, the fourth port being connected to the gain medium; the multiplexing module is configured to receive a first optical signal from the first port and pump light from the pump laser, and combine the first optical signal and the pump light to obtain a second optical signal, and transmit the second optical signal to the gain medium; the gain medium is configured to amplify optical power of the first optical signal based on the pump light to obtain a third optical signal, and transmit the third optical signal to the detector; and the detector is configured to perform photoelectric conversion on the third optical signal to obtain an electrical signal. The beneficial effects of the present aspect are described in the first aspect, and will not be repeated here.

[0038] In a fifth aspect, an embodiment of the present application provides an optical receiver, comprising a processor and an optical receiving module as described in the fourth aspect above, the processor being electrically connected to the detector, and the detector being configured to send the electrical signal to the processor.

[0039] In a sixth aspect, an embodiment of the present application provides a radar, comprising a processor and an optical transmitting module connected to the processor, the optical transmitting module being as described in the second aspect above; the processor is configured to send a detection electrical signal to the optical transmitting module; and the optical transmitting module is configured to process the detection electrical signal into output light, and the output light is configured to detect related information of a target object.

[0040] In a seventh aspect, an embodiment of the present application provides a radar, comprising a processor and an optical receiving module connected to the processor, the optical receiving module being as described in the third aspect above; the optical receiving module is configured to receive the first optical signal reflected by a target object, and send the electrical signal to the processor; and the processor is configured to detect related information of the target object based on the electrical signal.

[0041] In an eighth aspect, an embodiment of the present application provides an optical communication device, comprising an optical transmitter as described in the third aspect and / or an optical receiver as described in the fifth aspect.

[0042] In a ninth aspect, an optical network is provided, comprising a first optical communication device and a second optical communication device, the first optical communication device and the second optical communication device being connected by an optical fiber link, the optical fiber link comprising one or more optical fiber amplifiers, the optical fiber amplifiers being as described in any one of the first aspect. BRIEF DESCRIPTION OF DRAWINGS

[0043] FIG. 1 is a structural diagram of an erbium-doped optical fiber amplifier according to the prior art;

[0044] FIG. 2 is a structural diagram of a first embodiment of an optical fiber amplifier according to the present application;

[0045] FIG. 3 is a structural diagram of a second embodiment of an optical fiber amplifier according to the present application;

[0046] FIG. 4a is a structural diagram of a first cross-sectional structure of a photonic integrated chip according to the present application;

[0047] FIG. 4b is a structural diagram of a side view of evanescent wave coupling between the first waveguide layer and the second waveguide layer shown in FIG. 4a;

[0048] FIG. 4c is a structural diagram of a top view of evanescent wave coupling between the first waveguide layer and the second waveguide layer according to the present application;

[0049] FIG. 5 is a structural diagram of a second cross-sectional structure of a photonic integrated chip according to the present application;

[0050] FIG. 6a is a structural diagram of a third cross-sectional structure of a photonic integrated chip according to the present application;

[0051] FIG. 6b is a structural diagram of a fourth cross-sectional structure of a photonic integrated chip according to the present application;

[0052] FIG. 7 is a structural diagram of an embodiment of an optical transmitter according to the present application;

[0053] FIG. 8 is a structural diagram of an embodiment of an optical receiver according to the present application;

[0054] FIG. 9 is a structural diagram of a first embodiment of a radar according to the present application;

[0055] FIG. 10 is a structural diagram of a second embodiment of a radar according to the present application;

[0056] FIG. 11 is a structural diagram of an embodiment of a vehicle according to the present application. DETAILED DESCRIPTION

[0057] In the following, the technical solutions in the embodiments of the present application will be described with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative work fall within the scope of the present application.

[0058] The embodiment of the present application provides an optical fiber amplifier, specifically, the type of the optical fiber amplifier is EDFA, it is to be clear that the type of the optical fiber amplifier in the embodiment is an optional example, and is not limited, for example, the type of the optical fiber amplifier provided in the embodiment can also be a bismuth (Bi), praseodymium (Pr), thulium (Tm), ytterbium (Yb) doped optical fiber amplifier, etc. The optical fiber amplifier is used to amplify the optical power of the optical signal in the process of optical signal transmission. For example, the optical fiber amplifier is used to realize relay amplification, specifically, the optical fiber amplifier is installed at the relay station of the optical cable or the intermediate position of the long-distance transmission link to compensate for the transmission loss of the optical signal, thereby prolonging the transmission distance of the optical signal. For another example, the optical fiber amplifier is installed before the input end of the optical receiver to amplify the optical signal about to enter the optical receiver, improve the detection performance of the signal and the sensitivity of the optical receiver. For another example, the optical receiver integrates the optical fiber amplifier to amplify the optical signal received by the optical receiver, improve the detection performance of the signal and the sensitivity of the optical receiver. In addition, the optical fiber amplifier is installed after the optical transmitter and before the optical signal input link, or the optical transmitter integrates the optical fiber amplifier to amplify the optical signal output by the optical transmitter to prolong the transmission distance between the next hop node (such as another optical fiber amplifier, for example, an optical receiver, etc.). The optical fiber amplifier can compensate for the loss of the optical signal to prolong the transmission distance of the optical signal. In the process of optical signal transmission, the optical signal may be affected by various interference and noise, resulting in a decline in signal quality. In order to ensure the stable transmission of the optical signal, the optical fiber amplifier can maximize the improvement of the signal quality and reduce the influence of noise and interference.

[0059] FIG. 2 is a structural diagram of a first embodiment of the optical fiber amplifier provided by the present application. The optical fiber amplifier shown in the embodiment specifically includes a photonic integrated circuit (PIC) 210, a pump laser 215, and a gain medium 216. The PIC 210 is an optical signal processing chip manufactured by using a planar optical waveguide technology, and has the characteristics of high integration, miniaturization, and high reliability. Therefore, the PIC 210 can effectively improve the integration and reliability of the optical fiber amplifier. The PIC 210 can be a silicon-on-insulator optical chip, a silicon dioxide optical chip, a silicon oxynitride optical chip, a lithium niobate or lithium tantalate optical chip, etc. For example, the PIC 210 can be produced by using a mature complementary metal-oxide-semiconductor (CMOS) process, and the manufacturability, size, and cost of the PIC 210 are greatly optimized, thereby greatly reducing the size, cost, and failure rate of the optical fiber amplifier, and improving the manufacturability. The PIC 210 has a first port, a second port, and a third port. The first port and the second port are connected by a multiplexing module 212. The first port can be connected to a first optical fiber 230, and the first optical fiber 230 is used to input a first optical signal to be amplified into the PIC 210. Optionally, the first port can be a first edge coupler (EC) 211, and the first EC 211 can improve the coupling efficiency of the first optical signal transmitted by the first optical fiber 230 into the PIC 210, and reduce the loss in the coupling process. Specifically, the first optical signal is converted from a Gaussian mode spot at the junction of the first optical fiber 230 and the PIC 210 into an on-chip optical waveguide mode spot, and is then transmitted along a first optical waveguide 241 to the multiplexing module 212. The first optical waveguide 241 is connected between a first input port of the multiplexing module 212 and the first EC 211. The type of the first EC 211 is not limited in the embodiment, and for example, the first EC 211 can be a butt coupling or an edge coupling, etc. The first port is not limited in the embodiment, as long as the first optical signal transmitted by the first optical fiber 230 can be incident on the first optical waveguide 241 through the first port, and the first optical waveguide 241 can transmit the first optical signal to the multiplexing module 212. It should be noted that the first EC 211 is connected to the first optical fiber 230 in the embodiment, but in other examples, the first EC 211 can not be connected to an optical fiber, but directly receives the first optical signal. The specific manner in which the first EC 211 receives the first optical signal is not limited.

[0060] The second input port of the multiplexing module 212 is connected with the second port of the PIC 210 through a second optical waveguide 242, and the pump laser 215 is connected with the second port through an optical fiber, where the second port can be the second EC 214. For details of the second EC 214, refer to the description of the first EC 211, which will not be repeated here. The pump light emitted by the pump laser 215 is transmitted to the second EC 214 through the optical fiber, and the pump light emitted by the second EC 214 is transmitted to the second input port of the multiplexing module 212 along the second optical waveguide 242. It can be understood that the multiplexing module 212 receives the first optical signal from the first optical fiber 230 through the first input port, and receives the pump light from the pump laser 215 through the second input port. The multiplexing module 212 combines the first optical signal and the pump light to obtain the second optical signal. The wavelength range of the pump light is not limited in the embodiment, for example, the wavelength of the pump light can be around 980 nanometers (nm). The type of the multiplexing module 212 is not limited in the embodiment, for example, the multiplexing module 212 can be a wavelength division multiplexer (WDM), and the implementation of the WDM includes but is not limited to a mach–zehnder interferometer (MZI) filter, an arrayed waveguide grating (AWG), a multimode interference coupler, a directional coupler, an adiabatic coupler, a micro-ring resonator, an Echelle Grating, a waveguide grating filter, or a pixel array type wavelength division multiplexer based on inverse design, etc.

[0061] The out port of the multiplexing module is connected with a third port through a third optical waveguide 243, and the third port is connected with the gain medium 216. The third port can be a third EC 213. For the third EC 213, refer to the description of the first EC 211, and details are not described herein. It can be understood that the second optical signal emitted by the multiplexing module 212 is transmitted to the third EC 213 through the third optical waveguide 243, and the second optical signal emitted by the third EC 213 is incident on the gain medium 216. Specifically, under the action of the pump light in the second optical signal, the atoms or molecules inside the gain medium 216 are transitioned from a low-energy ground state to a high-energy excited state. The atoms or molecules in the excited state transfer energy to the first optical signal in the second optical signal through stimulated radiation, thereby amplifying the optical power of the first optical signal to output a third optical signal. The gain medium 216 transmits the third optical signal to the second optical fiber 231. It can be understood that the optical power of the third optical signal transmitted by the second optical fiber 231 is greater than the optical power of the first optical signal transmitted by the first optical fiber 230. It should be noted that the gain medium 216 in the embodiment is an erbium-doped optical fiber. It should be noted that the type of the gain medium 216 in the embodiment is an optional example and is not limited. In other examples, the type of the gain medium 216 can also be a bismuth (Bi), praseodymium (Pr), thulium (Tm), ytterbium (Yb) doped fiber amplifier, Raman fiber, etc., and details are not limited.

[0062] The fiber amplifier shown in the embodiment is produced by using a mature CMOS semiconductor process. The PIC has the characteristics of large scale and high yield. A single PIC can integrate multiple devices including but not limited to the multiplexing module and each EC shown in the above embodiment. The integration of the fiber amplifier is improved, and the space volume occupied by the fiber amplifier is reduced. The number of devices in a discrete state included in the fiber amplifier is reduced by the PIC, so that the fusion fiber points and the disc fiber length between the devices of the fiber amplifier as a whole are effectively reduced, and the manufacturability of the fiber amplifier is improved. The multiplexing module on the PIC directly connects the first optical fiber, the pump laser, and the gain medium through the optical waveguide of the PIC, thereby improving the reliability of optical signal transmission. Moreover, the PIC 210 integrates multiple devices (for example, the multiplexing module and each EC shown in the above embodiment). The different devices on the PIC 210 are coupled through the optical waveguide. The coupling is not required to be performed through the free space optical path. The sensitivity of the PIC to the optical path alignment precision and dirt is greatly reduced, and the failure of optical signal transmission is inhibited or even avoided.

[0063] It should be noted that the number and type of devices included in the PIC 210 are not limited by the present embodiment. For example, FIG. 3 is a schematic diagram of a second embodiment of a fiber amplifier according to the present application. The fiber amplifier shown in the present embodiment includes a PIC 310, a pump laser 315, and a gain medium 316. For details, please refer to the corresponding description of FIG. 2, and no further elaboration is made. The PIC 310 shown in the present embodiment includes a fourth port and a filter module 318. For example, the fourth port can be a fourth EC 317. For details of the fourth EC 317, please refer to the corresponding description of the first EC of FIG. 2, and no further elaboration is made. The fourth EC 317 is connected between the filter module 318 and the gain medium 316, wherein the fourth EC 317 is connected to the filter module 318 through the optical waveguide of the PIC 310. The gain medium 316 transmits a third optical signal to the filter module 318 through the fourth EC 317. For details of the third optical signal, please refer to the corresponding description of FIG. 2, and no further elaboration is

[0064] The filter module 318 shown in this embodiment can include one or more filters. For example, the filter module 318 can include a tunable optical filter (TOF) that can effectively filter out out-of-band noise in the third optical signal. In an optical communication system, signals are usually transmitted within a specific wavelength or frequency range, which is referred to as a signal bandwidth. Out-of-band noise refers to noise that is outside the signal bandwidth and interferes with signal transmission. The TOF has the ability to selectively pass or block specific wavelengths or frequencies. When the third optical signal passes through the TOF, the optical signal with a wavelength within the signal bandwidth is allowed to pass through the TOF, and the wavelength outside the signal bandwidth is filtered out. The filtering effect of the TOF on the out-of-band noise can improve the signal-to-noise ratio of the fiber amplifier, improve the signal quality of the optical signal output by the fiber amplifier, reduce the bit error rate of the optical signal output by the fiber amplifier when it reaches the receiving end, and thus improve the communication efficiency. The description of the function of the TOF in this embodiment is an optional example and is not limited. For example, in other embodiments, the TOF can also be used to monitor the performance of the fiber amplifier. For example, by adjusting the parameters of the TOF, the optical signal intensity, the optical signal-to-noise ratio, and other parameters at different wavelengths can be monitored in real time, providing a basis for optimization and maintenance of the fiber amplifier. For another example, the filter module 318 can also include a gain flattening filter (GFF). In the process of performing optical power amplification on the third optical signal to obtain the third optical signal, the gain medium introduces a difference in gain to the third optical signal, resulting in an uneven distribution of optical power between the wavelengths included in the third optical signal. The GFF can correct the gain curve (or gain spectrum) corresponding to the third optical signal. The gain curve corresponding to the fourth optical signal after correction by the GFF is in a flat state, so that the optical power of each wavelength included in the fourth optical signal is in a balanced state. The implementation of the GFF shown in this embodiment can use a cascaded mach–zehnder interferometer (MZI) filter, a micro-ring filter, a waveguide grating filter, and other filters. The specific type of filter is not limited in this embodiment. It can be understood that the filter module 318 filters the third optical signal to output the fourth optical signal. The number of filters included in the filter module 318 and the specific type of filter are not limited in this embodiment.

[0065] Optionally, the PIC 310 shown in the embodiment further comprises a VOA 319, which receives the fourth optical signal from the filtering module 318 and adjusts the optical power of the fourth optical signal to obtain a fifth optical signal. Specifically, the VOA 319 is configured to precisely adjust the optical power of the fourth optical signal, so as to ensure that the fifth optical signal after the adjustment of the VOA 319 can be correctly received and processed in the transmission process. In the example, the third optical signal input into the PIC 310 from the gain medium 316 is first filtered by the filtering module 318 and then adjusted in optical power by the VOA 319. In other examples, the VOA can be connected between the filtering module and the fourth EC through the optical waveguide of the PIC. In this case, the third optical signal entering the PIC through the fourth EC is first adjusted in optical power by the VOA and then filtered by the filtering module. The specific implementation is not limited.

[0066] Optionally, the PIC shown in the embodiment further comprises an optical tap 320 and an mPD 322, wherein the optical tap 320 is connected to the VOA 319 through the optical waveguide of the PIC 310, one port of the optical tap 320 is connected to the mPD 322 through the optical waveguide, and the other port of the optical tap 320 is connected to a fifth port (for example, the fifth EC 321) through the optical waveguide. The fifth EC 321 is described in detail in FIG. 2. The optical tap 320 receives the fifth optical signal from the VOA 319 through the optical waveguide of the PIC 310, splits the fifth optical signal to obtain monitoring light and output light, and transmits the monitoring light to the mPD 322 and transmits the output light to the fifth EC 321. The optical power of the monitoring light is less than the optical power of the output light, for example, the optical power of the monitoring light is 3% of the optical power of the fifth optical signal, and the optical power of the output light is 97% of the optical power of the fifth optical signal. The mPD 322 is used to convert the monitoring light into a monitoring electrical signal, and the mPD 322 detects the power of the monitoring electrical signal to detect the optical power of the output light, and further detects the output optical power of the fiber amplifier. The mPD 322 monitors whether the fiber amplifier is in a normal working state according to the output optical power to maintain the stability of the fiber amplifier. The mPD 322 can also realize early warning of the working condition of the fiber amplifier through the change of the output optical power of the fiber amplifier, for example, if the mPD 322 detects that the output optical power of the fiber amplifier suddenly decreases, it is determined that the optical signal is attenuated or interfered during transmission. For another example, if the mPD 322 detects that the output optical power of the fiber amplifier is too low, the optical power of the optical signal can be increased by adjusting the pump laser 315 or the VOA 319 to ensure the signal quality of the output optical signal of the fiber amplifier. In this embodiment, the optical tap 320, the VOA 319, the filter module 318, and the fourth EC 317 are connected in sequence as an example. In other examples, the optical tap 320, the filter module 318, the VOA 319, and the fourth EC 317 are connected in sequence. For another example, the optical tap 320 and the fourth EC 317 can be connected only through the VOA 319. For another example, the optical tap 320 and the fourth EC 317 can be connected through only the filter module 318. The fifth EC 321 is connected to the second optical fiber 331, and the fifth EC 321 is used to input the output light from the optical tap 320 into the second optical fiber 331. The second optical fiber 331 is used to transmit the output light to the next hop node (for example, another fiber amplifier, for another example, an optical communication device, etc.).

[0067] It can be understood that the optical fiber amplifier shown in the embodiment, the multiplexing module, the filtering module, the VOA, the optical splitter, the mPD and other devices do not need to adopt a separate architecture, but are integrated by a single PIC multiplexing module, filtering module, VOA, optical splitter, mPD and other devices, which reduces the material consumption of the optical fiber amplifier, improves the integration of the optical fiber amplifier, reduces the space occupied by the optical fiber amplifier, and the PIC shown in the embodiment integrates multiple devices, and the devices included in the PIC do not need to be connected through fusion fiber points and fiber discs, but are directly connected through the optical waveguide of the PIC. Therefore, the length of the fusion fiber points and the fiber discs of the optical fiber amplifier is effectively reduced, the manufacturability of the optical fiber amplifier is improved, and the PIC 210 integrates multiple devices (such as the multiplexing module, filtering module, VOA, optical splitter, mPD and other devices shown above). The different devices on the PIC are coupled through the optical waveguide, and do not need to be coupled through the free space optical path, which greatly reduces the sensitivity of the PIC to the optical path alignment accuracy and contamination, and inhibits or even avoids the failure of optical signal transmission.

[0068] FIG. 4a is a first cross-sectional structure example of a photonic integrated chip provided by the present application. The PIC shown in the embodiment specifically includes a substrate 401, and in the direction away from the surface of the substrate 401, the PIC includes a first waveguide layer 402, a detector layer 404 and a second waveguide layer 403 in sequence. It can be understood that the second waveguide layer 403, the detector layer 404, the first waveguide layer 402 and the substrate 401 included in the PIC are arranged in sequence. The material of the first waveguide layer 402 is transparent to the optical communication band, for example, silicon. The detector layer 404 can be germanium, germanium-silicon alloy or group III-V semiconductor material, etc. The material of the second waveguide layer 403 has a large band gap and is transparent to pump light with a wavelength of 980 nm, and can be silicon nitride, silicon oxynitride, doped silicon oxide, lithium niobate, lithium tantalate, etc. The first waveguide layer 402 and the second waveguide layer 403 can form various devices included in the optical fiber amplifier through structural design. For details, please refer to the examples shown below:

[0069] Example 1

[0070] The band gap of the second waveguide layer 403 is wide, so it can be used to transmit shorter wavelength pump light. The first waveguide layer 402 cannot transmit pump light because its band gap is narrow. Therefore, the first waveguide layer 402 can be designed to form the VOA 319, the optical splitter 320, the filter module 318, the first EC 311, the fourth EC 317, and the fifth EC 321 shown in FIG. 3. The second waveguide layer 403 can be designed to form the third EC 313, the second EC 314, and the multiplexing module 312 shown in FIG. 3. The specific design can be seen from Table 1:

[0071] Table 1

[0072] As can be seen from Table 1 and the example shown in FIG. 3, the first EC 311 of the first waveguide layer 402 receives the first optical signal. The second EC 314 of the second waveguide layer 403 receives the pump light from the pump laser 315. In the example shown, a waveguide conversion module can also be connected between the first EC 311 and the multiplexing module 312. The waveguide conversion module can couple the first optical signal from the first EC 311 to the multiplexing module 312. The multiplexing module 312 of the second waveguide layer 403 combines the first optical signal and the pump light to obtain a second optical signal, and then couples the second optical signal to the third EC 313 of the second waveguide layer 403. The gain medium 316 amplifies the optical power of the first optical signal in the second optical signal to obtain a third optical signal, and transmits the third optical signal to the fourth EC 317 of the first waveguide layer 402. The fourth EC 317 transmits the third optical signal to the filter module 318 of the first waveguide layer 402. The filter module 318 filters the third optical signal to obtain a fourth optical signal, and transmits the fourth optical signal to the VOA 319. The VOA 319 adjusts the fourth optical signal to obtain a fifth optical signal, and transmits the fifth optical signal to the optical splitter 320 of the first waveguide layer 402. The optical splitter 320 splits the fifth optical signal to obtain a monitoring light and an output light. The first waveguide layer 402 couples the monitoring light to the detector layer 404 by butt coupling or evanescent wave coupling. The detector layer 404 is designed to form the mPD 322. The optical splitter 320 of the first waveguide layer 402 couples the output light to the fifth EC 321 of the first waveguide layer 402, and the fifth EC 321 couples the output light to the second optical fiber 331. The PIC also includes a cladding layer 400 that covers the first waveguide layer 402, the detector layer 404, and the second waveguide layer 403. The cladding layer 400 is made of a material with a low refractive index, such as silica.

[0073] Example 2

[0074] As shown in the example, part of the VOA 319, the optical splitter 320, the filter module 318, the first EC 311, the fourth EC 317, and the fifth EC 321 shown in FIG. 3 are formed by the first waveguide layer 402 through structural design, and another part is formed by the second waveguide layer 403 through structural design. The second waveguide layer 403 can also form the third EC 313, the second EC 314, and the multiplexing module 312 shown in FIG. 3 through structural design. For specific design, refer to Table 2 shown below:

[0075] Table 2

[0076] In the example shown in Table 2, among the VOA 319, the optical splitter 320, the filter module 318, the fist EC 311, the fourth EC 317, and the fifth EC 321, the first EC 311, the fourth EC 317, and the fifth EC 321 are formed by the second waveguide layer 403 through structural design, and the VOA 319, the optical splitter 320, and the filter module 318 are formed by the first waveguide layer 402 through structural design. It should be noted that the example does not limit the types of devices formed by the first waveguide layer 402 and the second waveguide layer 403, as long as the VOA 319, the optical splitter 320, the filter module 318, the fourth EC 317, and the fifth EC 321 are formed by the first waveguide layer 402 and the second waveguide layer 403 through structural design.

[0077] In combination with Table 2 and the example shown in FIG. 3, the first EC 311 of the second waveguide layer 403 receives the first optical signal. The second EC 314 of the second waveguide layer 403 receives the pump light from the pump laser 315. The multiplexing module 312 of the second waveguide layer 403 combines the first optical signal and the pump light to obtain a second optical signal, and then couples the second optical signal to the third EC 313 of the second waveguide layer 403. The gain medium 316 amplifies the optical power of the first optical signal in the second optical signal to obtain a third optical signal, and transmits the third optical signal to the fourth EC 317 of the second waveguide layer 403. The fourth EC 317 of the second waveguide layer 403 transmits the third optical signal to the filtering module 318 of the first waveguide layer 402. FIG. 4b is a side view of an example of evanescent coupling between the first waveguide layer and the second waveguide layer shown in FIG. 4a. FIG. 4c is a top view of an example of evanescent coupling between the first waveguide layer and the second waveguidelayer shown in FIG. 4a. It can be understood that the fourth EC 317 of the second waveguide layer 403 couples the third optical signal to the filtering module 318 of the first waveguide layer 402 through evanescent coupling. The filtering module 318 filters the third optical signal to obtain a fourth optical signal, and transmits the fourth optical signal to the VOA 319. The VOA 319 adjusts the fourth optical signal to obtain a fifth optical signal, and transmits the fifth optical signal to the optical splitter 320 of the first waveguide layer 402. The optical splitter 320 splits the fifth optical signal to obtain a monitoring optical signal and an output optical signal. The first waveguide layer 402 couples the monitoring optical signal to the detector layer 404 through butt coupling or evanescent coupling. The detector layer 404 is designed to form the mPD 322. The optical splitter 320 of the first waveguide layer 402 couples the output optical signal to the fifth EC 321 of the second waveguide layer 403 through evanescent coupling. The fifth EC 321 couples the output optical signal to the second optical fiber 331. The PIC further includes the cladding layer 400. For the description of the cladding layer 400, please refer to the example 1, and the specific description is not repeated here.

[0078] As shown in FIG. 1, the optical fiber amplifier shown in FIG. 1 includes devices in a discrete state, and the transmission of optical signals is performed by means of spatial optical coupling. The transmission performance of optical signals is very sensitive to optical path alignment accuracy and contamination. For example, the core optical elements in the independently packaged wavelength division multiplexer, adjustable optical attenuator, and adjustable optical filter, such as thin film filters, micro-mirrors, and micro-lenses, are usually coupled to the optical fiber collimator through a free space optical path, and then connected with the optical fiber. If the optical path is displaced or contaminated, the loss of optical signals will be deteriorated, and even the transmission of optical signals will be failed. The optical fiber amplifier shown in the embodiment includes various devices in the PIC formed in the first waveguide layer, the second waveguide layer, and the detector layer, and the first waveguide layer, the second waveguide layer, and the detector layer are tightly covered by the cladding layer. The transmission of optical signals in the devices included in the PIC is not through free space, and thus the PIC is not sensitive to contamination. That is, the contamination will not affect the transmission of optical signals in the devices included in the PIC, and the failure rate of the transmission of optical signals in the optical fiber amplifier is reduced.

[0079] FIG. 5 is a second cross-sectional structure example of the PIC provided in the application. The PIC shown in the embodiment specifically includes a substrate 501. In the direction perpendicular to the surface of the substrate 501, the PIC includes, in sequence, a detector layer 504, a first waveguide layer 502, a second waveguide layer 503, and the substrate 501. It can be understood that the detector layer 504, the first waveguide layer 502, the second waveguide layer 503, and the substrate 501 included in the PIC are arranged in sequence. For example, the first waveguide layer 502 can be designed to form the VOA 319, the optical splitter 320, the filter module 318, the first EC 311, the fourth EC 317, and the fifth EC 321 shown in FIG. 3. The second waveguide layer 503 can be designed to form the third EC 313, the second EC 314, and the multiplexing module 312 shown in FIG. 3. For details, please refer to the first example shown in FIG. 4a, and details are not repeated. For another example, part of the VOA 319, the optical splitter 320, the filter module 318, the

[0080] FIG. 6a is a third cross-sectional structure example of the photonic integrated chip provided by the present application. The PIC shown in the embodiment specifically includes a substrate 611, and in the direction perpendicular to the surface of the substrate 611, the PIC includes the substrate 611, a detector layer 614, a first waveguide layer 612, and a second waveguide layer 613 in sequence. For example, the first waveguide layer 612 is designed to form the VOA 319, the optical splitter 320, the filter module 318, the first EC 311, the fourth EC 317, and the fifth EC 321 shown in FIG. 3. The second waveguide layer 613 is designed to form the third EC 313, the second EC 314, and the multiplexing module 312 shown in FIG. 3. For details, please refer to the corresponding example 1 shown in FIG. 4a, and details are not described herein. For another example, part of the VOA 319, the optical splitter 320, the filter module 318, the

[0081] FIG. 6b is a fourth cross-sectional structure example of the photonic integrated chip provided by the present application. The PIC shown by the embodiment specifically includes a substrate 601, and the surface of the substrate 601 includes a waveguide layer 602, wherein the waveguide layer 602 is designed to form a VOA, an optical splitter, a filter module, various ECs, a multiplexing module, etc. The PIC further includes a cladding layer 600 covering the waveguide layer 602, and the surface of the cladding layer 600 includes a detector layer 603. The detector layer 603 is designed to form an mPD, and the mPD is physically connected to the surface of the PIC by a bonding method to realize the transmission of optical signals. Optionally, the embodiment shown between the waveguide layer 602 and the detector layer 603 can have a coupling module for efficiently coupling the optical signals from the waveguide layer 602 to the detector 603. For example, the coupling module is used to efficiently couple the monitoring light output from the optical splitter module of the waveguide layer 602 to the mPD of the detector 603, as shown in the example of FIG. 3. For example, the coupling module can include at least one of an evanescent wave coupling structure, a grating, a lens group, and a reflection group. It should be noted that the embodiment takes the surface of the substrate 601 including a waveguide layer as an example, and in other examples, the surface of the substrate 601 can include two or more waveguide layers, and the waveguide layers are coupled by evanescent waves to transmit optical signals, and the number of waveguide layers is not limited.

[0082] FIG. 7 is a structural diagram of an embodiment of an optical transmitter provided by the present application. The optical transmitter provided by the present embodiment integrates a fiber amplifier to improve the output optical power of the optical transmitter. The optical transmitter shown in the present embodiment specifically includes a processor 751, a driver 753, and an optical transmitting module, wherein the optical transmitting module specifically includes a light source 752, a PIC 710, a pump laser 716, and a gain medium 717. For the description of the pump laser 716 and the gain medium 717, please refer to the corresponding description in FIG. 2, and details are not described herein. The processor 751 is connected to the driver 753, and the driver 753 is connected to the PIC 710. The present embodiment does not limit the type of the processor 751. For example, the processor 751 can be one or more chips, or one or more integrated circuits. For another example, the processor 751 can be one or more of a neural processing unit (NPU), an optical digital signal processor (oDSP), a field-programmable gate array (FPGA), an application specific integrated circuit (ASIC), a system on chip (SoC), a central processor unit (CPU), a network processor (NP), a microcontroller unit (MCU), a programmable logic device (PLD), a network card chip, a storage interface chip, or other integrated chips, and details are not described herein. The PIC 710 has a first port, a second port, and a third port. For example, the first port is a first EC 711, the second port is a second EC 715, and the third port is a third EC 714. For the description of the first EC 711, the second EC 715, and the third EC 714, please refer to the corresponding description in FIG. 2, and details are not described hereinThe light source 752 is connected to the first EC 711 through the first optical fiber 730. It is to be noted that the embodiment takes the first optical fiber 730 connected between the light source 752 and the first EC 711 as an example, so that the first light signal emitted by the light source 752 can be incident on the first EC 711 through the first optical fiber 730. It is not limited, for example, in other examples, the light source 752 and the first EC 711 are in a state of spatial optical path alignment, then the first light signal emitted by the light source 752 can be directly incident on the first EC 711. The type of the light source 752 is not limited in the embodiment, for example, the light source 752 can be a distributed Bragg reflector (DBR), a Fabry-Perot laser, a distributed feedback laser, a modulated grating Y-branch (MG-Y laser), a multi-channel interference (MCI laser), a V-coupled cavity laser (V-cavity laser), and a chirped sampled grating-distributed reflector laser (CSG-DR laser). The first EC 711 and the third EC 714 are connected to the optical modulator 712 and the multiplexing module 713 in sequence through the optical waveguide of the PIC. Specifically, the optical modulator 712 is connected to the first EC 711 through the first optical waveguide 741 of the PIC 710, the optical modulator 712 is connected to the multiplexing module 713 through the second optical waveguide 742 of the PIC 710, the multiplexing module 713 is connected to the second EC 715 through the third optical waveguide 743 of the PIC 710, and the multiplexing module 713 is connected to the third EC 714 through the fourth optical waveguide 744 of the PIC 710. For the description of the multiplexing module 713, please refer to the corresponding description of FIG. 2, and details are not described herein. The type of the optical modulator 712 can be an in-phase and quadrature (IQ) modulator, a Mach-Zehnder modulator (MZM), a micro ring modulator (MRM), or an electro-absorption modulator. The type of the optical modulator 712 is not limited in the embodiment. The processor 751, the driver 753, and the optical modulator 712 are connected in sequence in the embodiment.

[0083] The process of outputting optical power of the optical transmitter is that the light source 752 transmits the first optical signal to the first EC 711 through the first optical fiber 730. The processor 751 sends an electrical signal to the driver 753, the driver 753 transmits the amplified electrical signal to the optical modulator 712, and the optical modulator 712 modulates the electrical signal on the first optical signal to obtain a modulated optical signal. The optical modulator 712 transmits the modulated optical signal to the first input port of the multiplexing module 713. The pump light emitted by the pump laser 716 is transmitted to the second EC 715 through the optical fiber, and the pump light emitted by the second EC 715 is transmitted along the third optical waveguide 743 to the second input port of the multiplexing module 713. It can be understood that the multiplexing module 713 receives the modulated optical signal from the optical modulator 712 through the first input port and receives the pump light from the pump laser 716 through the second input port. The multiplexing module 713 combines and modulates the pump light and the modulated optical signal to obtain a second optical signal. For a description of the pump light and the multiplexing module 713, please refer to the corresponding description of FIG. 2, and details are not described herein. The output port of the multiplexing module 713 is connected to the third EC 714 through the fourth optical waveguide 744, and the second optical signal emitted from the third EC 714 is incident on the gain medium 717, which amplifies the optical power of the modulated optical signal in the second optical signal to output an amplified third optical signal through the second optical fiber 731. For a description of the gain medium 717 amplifying the optical signal, please refer to the corresponding description of FIG. 2, and details are not described herein.

[0084] The number and type of devices included in the PIC 710 are not limited in the embodiment, for example, the PIC can further include a fourth EC, a filtering module, a VOA, an optical splitter, an mPD, a fifth EC, and the like. For a detailed description, please refer to the corresponding description of FIG. 3, and details are not described herein. The optical transmitter shown in the embodiment can further include an ISO connected between the gain medium and the fourth EC. For a description of the ISO, please refer to the corresponding description of FIG. 3, and details are not described herein.

[0085] The embodiment of the application further provides an optical transmitting module, which includes a light source, a PIC, a pump laser, and a gain medium. For a detailed description of the optical transmitting module, please refer to the corresponding description of FIG. 7, and details are not described herein.

[0086] Figure 8 is a structural diagram of an embodiment of the optical receiver provided by the present application. The embodiment provides an optical receiver integrated with a fiber amplifier to improve the detection performance and sensitivity of the optical receiver. The optical receiver shown in the embodiment specifically includes a processor (not shown in the figure) and an optical receiving module, wherein the optical receiving module specifically includes a PIC 810, a pump laser 822, and a gain medium 823. For the descriptions of the pump laser 822, the processor, and the gain medium 823, please refer to the corresponding descriptions in Figure 7, and no further description is provided herein. The PIC 810 has a first port, a second port, a third port, and a fourth port. For example, the first port is a first EC 811, the second port is a second EC 814, the third port is a third EC 813, and the fourth port is a fourth EC 815. For the descriptions of the first EC 811, the second EC 814, the third EC 813, and the fourth EC 815, please refer to the corresponding descriptions in Figure 3, and no further description is provided herein. The PIC 810 includes the first EC 811, a multiplexing module 812, and the third EC 813 connected in sequence, the multiplexing module 812 is further connected to the second EC 814, and the fourth EC 815 is connected between a detector 816 and the gain medium 823. Specifically, the first EC 811 is connected to a first input port of the multiplexing module 812 through a first optical waveguide of the PIC 810, the second EC 814 is connected to a second input port of the multiplexing module 812 through a second optical waveguide of the PIC 810, an output port of the multiplexing module 812 is connected to the third EC 813 through a third optical waveguide of the PIC 810, and the fourth EC 815 is connected to the detector 816 through a fourth optical waveguide of the PIC 810. The detector 816 can be a PIN diode or an APD, etc.

[0087] The process that the optical receiver receives the optical signal is that the first EC 811 of the PIC 810 receives the first optical signal from the previous hop node (for example, another optical fiber amplifier, or for example, the optical transmitter) through the first optical fiber 830, the pump laser 822 sends the pump light to the second EC 814 of the PIC 810, the second EC 814 transmits the pump light to the multiplexing module 812, the multiplexing module 812 combines the first optical signal and the pump light to obtain the second optical signal, the multiplexing module 812 transmits the second optical signal to the third EC 813, the third EC 813 transmits the second optical signal to the gain medium 823, the gain medium 823 amplifies the optical power of the first optical signal in the second optical signal to obtain the third optical signal, for the description of the gain medium 823 obtaining the third optical signal, please refer to the corresponding description of FIG. 2, and details are not described herein. The gain medium 823 transmits the second optical signal to the fourth EC 815, the fourth EC 815 transmits the second optical signal to the detector 816, and the detector 816 performs photoelectric conversion on the second optical signal to obtain an electrical signal. The optical receiver shown in the embodiment can also include a flexible printed circuit (FPC), which is used to electrically connect the detector 816 and the processor. The FPC is used to transmit the electrical signal from the detector 816 to the circuit board, which can be a PCB. The processor has been packaged in the PCB and is used to process the electrical signal. The embodiment does not limit the way the detector 816 is electrically connected to the processor, as long as the detector 816 can transmit the electrical signal to the processor.

[0088] The embodiment does not limit the devices included in the PIC 810, for example, the PIC can also include a filtering module, a VOA, an optical splitter, an mPD, a fifth EC, and the like. For specific descriptions, please refer to the corresponding description of FIG. 3, and details are not described herein. The optical receiver shown in the embodiment can also include an ISO 821 connected between the gain medium and the fourth EC. For the description of the ISO 821, please refer to the corresponding description of FIG. 3, and details are not described herein.

[0089] The embodiment of the application also provides an optical communication device, which includes an optical transmitter and an optical receiver. For the description of the optical transmitter, please refer to the corresponding description of FIG. 7, and details are not described herein. For the description of the optical receiver, please refer to the corresponding description of FIG. 8, and details are not described herein.

[0090] The embodiments of the present application also provide an optical network, the optical network comprising a first optical communication device and a second optical communication device, the first optical communication device and the second optical communication device being connected through an optical fiber link, the optical fiber link comprising one or more optical fiber amplifiers, the description of the optical fiber amplifier can be found in the corresponding description of FIG. 2 to FIG. 6b, and details are not repeated. If the type of the optical network is a passive optical network (PON), then one of the first optical communication device and the second optical communication device is an optical line terminal (OLT), and the other is an optical network unit (ONU) or an optical network terminal (ONT). For another example, the optical network can also be applied to an optical transport network (OTN), and the first optical communication device and the second optical communication device are both OTN devices. For another example, the optical network is a wireless mesh network (Mesh) also known as a multi-hop network, the Mesh comprising a plurality of transmission devices with Mesh functions, and the first optical communication device and the second optical communication device are any two of the plurality of transmission devices connected. For another example, the optical network can be a fiber to the room (FTTR), and one of the first optical communication device and the second optical communication device is a master device, and the other is a slave device. The slave device in the FTTR can be deployed in each room of a home and used to connect with a station. It should be noted that the master device can also be referred to as a “master gateway”, a “master optical cat” or a “master FTTR device”, etc., and the slave device can also be referred to as a “slave gateway”, a “slave optical cat” or a “slave FTTR device”, etc., and the present application does not limit the specific name. The optical network shown in the present example can also be applied to any one or a combination of data center network (DCN), metropolitan area network (MAN), optical access network (OAN), Ethernet passive optical network (EPON), Ethernet (Ethernet), or flex Ethernet (FlexE), wavelength division multiplexing (WDM) network, etc., and details are not limited.Taking the first optical communication device as an example, with different application scenarios of the optical network, the device type of the first optical communication device can also be different. For example, the first optical communication device can be an optical transmission device, an optical access device, a router, a switch, a wireless base station, a wireless remote access device, a wireless baseband signal processing device, etc., or a computing server (usually referred to as a server), a high-performance computer (HPC), a storage server, or a memory resource pool, etc. The type of the first optical communication device is not limited in this example, as long as the first optical communication device has an electro-optical conversion function and an optical interface capable of connecting an optical fiber. Optionally, the first optical communication device can include an optical transmitting module as shown in FIG. 7 and / or an optical receiving module as shown in FIG. 8. For the description of the type of the second optical communication device, please refer to the description of the first optical communication device, and details are not described.

[0091] FIG. 9 is a structural example diagram of a first embodiment of a radar provided by the present application. The present embodiment takes a laser radar as an example, which is a target detection technology. The laser radar emits output light for detection, and the output light is diffusely reflected after encountering a target object to be detected. The distance, direction, height, speed, attitude, shape, etc. of the target object are determined by the reflected light signal. The laser radar is applied to intelligent driving vehicles, intelligent driving aircraft, 3D printing, virtual reality (VR), augmented reality (AR), service robots, etc. The intelligent driving in the present embodiment can be unmanned driving, autonomous driving, or assisted driving.

[0092] The laser radar 900 shown in the present embodiment includes a processor 901 and an optical transmitting module 902 connected to the processor 901. The description of the optical transmitting module 902 can be referred to the corresponding description in FIG. 7, and details are not described. Specifically, the processor 901 is configured to send a detection electrical signal to the optical transmitting module 902. The light source of the optical transmitting module 902 emits a first light signal according to the detection electrical signal. The optical transmitting module 902 amplifies the optical power of the first light signal to emit output light. The specific process is described in the corresponding description of FIGS. 2 and 3, and details are not described. When the output light encounters a target object, it is reflected on the surface of the target object. Specifically, after the target object receives the output light, the reflected first light signal is received by the laser radar 900. The laser radar 900 obtains related information of the target object according to the first light signal, such as point cloud information, coordinate information, trajectory information, etc.

[0093] FIG. 10 is a structural diagram of a second embodiment of the radar provided by the present application. After the target object receives the output light, the first light signal reflected back is received by the light receiving module 1002 of the laser radar 1000. The light receiving module 1002 is described in FIG. 8, and the specific description is not repeated. Specifically, after the target object receives the output light, the first light signal reflected back is received by the laser radar 1000. The light receiving module 1002 is configured to convert the first light signal into an electrical signal and send the electrical signal to the processor 1001. The processor 1001 is configured to obtain the related information of the target object according to the electrical signal.

[0094] Optionally, the laser radar provided by the embodiment of the present application can simultaneously include the light emitting module shown in FIG. 7 and the light receiving module shown in FIG. 8. The PIC included in the light emitting module and the PIC included in the light receiving module can be the same PIC or different PICs, and the specific implementation is not limited.

[0095] The laser radar shown in FIG. 9 and FIG. 10 can be applied to a vehicle as an example. In other examples, the laser radar can also be applied to a fixed radar (for example, a radar fixed on a road, a monitoring radar, a radar in an industrial scene, etc.). The laser radar can also be applied to a radar of a logistics warehouse unmanned vehicle or a radar of a smart home smart appliance (for example, the smart appliance is an automatic cleaning robot), and the specific implementation is not limited.

[0096] The embodiment also provides a vehicle, and the specific structure is described with reference to FIG. 11. FIG. 11 is a structural diagram of an embodiment of the vehicle provided by the present application. The vehicle shown in the example can be a car, a truck, a motorcycle, a public vehicle, a lawn mower, an entertainment vehicle, an amusement park vehicle, a trolley, a golf cart, a train, a cart or a drone, etc. The embodiment configures the vehicle 1100 to be in a fully or partially autonomous driving mode. The vehicle shown in the embodiment includes a vehicle body, which is configured to fix a sensing system 1120, an advanced driving assistance system (ADAS) 1110, a peripheral device 1130 and a computer system 1140.

[0097] The sensing system 1120 includes one or more sensors that sense environmental information about the surroundings of the vehicle 1100. For example, the sensing system 1120 can include a positioning system, which can be a global positioning system (GPS) system or a Beidou system, etc. The sensing system 1120 can also include an inertial measurement unit (IMU), a laser radar, a camera, etc. For a description of the laser radar, please refer to the corresponding embodiments of FIG. 9 or FIG. 10, which are not limited in particular. The sensing system 1120 can also include sensors for monitoring the internal systems of the vehicle 1100 (e.g., an in-vehicle air quality monitor, a fuel gauge, an engine oil temperature gauge, etc.). Sensor data from one or more of these sensors can be used to detect objects and their respective characteristics (location, shape, direction, speed, etc.). The positioning system can be used to estimate the geographic location of the vehicle 1100. The IMU is used to sense changes in the position and orientation of the vehicle 1100 based on inertial acceleration. The IMU can be a combination of an accelerometer and a gyroscope. The laser radar can use radio signals to detect target objects within the environment surrounding the vehicle 1100, for example, the target objects can be pedestrians, vehicles, or buildings, etc.

[0098] The ADAS 1110 senses the surrounding environment at any time during the driving of the vehicle, collects data, identifies, detects, and tracks static and dynamic objects, and combines navigation map data to perform system operation and analysis, so as to allow the driver to be aware of possible dangers in advance, thereby effectively increasing the comfort and safety of driving the vehicle. For example, the ADAS 1110 can control the vehicle through data obtained by the sensing system. For another example, the ADAS 1110 can control the vehicle through vehicle driving related information, which can be main data on the vehicle instrument panel (fuel consumption, engine speed, temperature, etc.), vehicle speed information, steering wheel angle information, or vehicle body attitude data, etc.

[0099] The vehicle 1100 interacts with external sensors, other vehicles, other computer systems, or users through the peripherals 1130. The peripherals 1130 can include a wireless communication system, an on-board computer, a microphone, and / or a speaker. For example, the on-board computer can provide information to a user of the vehicle 1100. The user interface can also operate the on-board computer to receive input from the user. The on-board computer can be operated through a touchscreen. In other cases, the peripherals 1130 can provide a means for the vehicle 1100 to communicate with other devices located within the vehicle. For example, the microphone can receive audio (e.g., voice commands or other audio input) from a user of the vehicle 1100. The speaker can output audio to a user of the vehicle 1100. The wireless communication system can wirelessly communicate with one or more devices, either directly or via a communication network.

[0100] Some or all of the functions of the vehicle 1100 are controlled by the computer system 1140. The computer system 1140 can control the functions of the vehicle 1100 based on input received from various systems (e.g., the sensing system 1120, the ADAS 1110, the peripherals 1130), as well as from the user interface. The computer system 1140 can include at least one processor that executes instructions stored in memory.

[0101] Those skilled in the art can clearly understand that, for the convenience and brevity of the description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the foregoing method embodiments, which will not be described here.

[0102] The above-described embodiments are merely used to illustrate the technical solutions of the present application, but not limit the present application; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand: the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced equivalently; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An optical fiber amplifier, characterized in that, The device includes a photonic integrated chip, a pump laser, and a gain medium. The photonic integrated chip includes a multiplexing module. The multiplexing module is connected to a first port of the photonic integrated chip through a first optical waveguide. The multiplexing module is connected to a second port of the photonic integrated chip through a second optical waveguide. The second port is connected to the pump laser. The multiplexing module is connected to a third port of the photonic integrated chip through a third optical waveguide. The third port is connected to the gain medium. The multiplexing module is used to receive a first optical signal from the first port and a pump light from the pump laser, and to combine the first optical signal and the pump light to obtain a second optical signal. The multiplexing module is also used to transmit the second optical signal to the gain medium, and the gain medium is used to amplify the optical power of the first optical signal based on the pump light to obtain a third optical signal.

2. The fiber optic amplifier according to claim 1, characterized in that, The photonic integrated chip also includes a fourth port and a tunable optical attenuator. The tunable optical attenuator is connected to the fourth port through the optical waveguide of the photonic integrated chip. The fourth port is connected to the gain medium. The gain medium is used to transmit the third optical signal to the tunable optical attenuator through the fourth port. The tunable optical attenuator is used to adjust the optical power of the third optical signal.

3. The fiber optic amplifier according to claim 1 or 2, characterized in that, The photonic integrated chip also includes a fourth port, an optical splitter, a fifth port, and a monitoring photodetector. The optical splitter is connected to the fourth port, the fifth port, and the monitoring photodetector respectively through the optical waveguide of the photonic integrated chip. The fourth port is connected to the gain medium. The gain medium is used to transmit the third optical signal to the optical splitter through the fourth port, and to split the third optical signal to obtain monitoring light and output light. The optical splitter is also used to transmit the monitoring light and output light to the monitoring photodetector and the fifth port respectively. The monitoring photodetector is used to detect the optical power of the output light based on the monitoring light.

4. The fiber optic amplifier according to any one of claims 1 to 3, characterized in that, The photonic integrated chip also includes a fourth port and a filtering module. The filtering module is connected to the fourth port through the optical waveguide of the photonic integrated chip. The fourth port is connected to the gain medium. The gain medium is used to transmit the third optical signal to the filtering module through the fourth port. The filtering module is used to filter the third optical signal.

5. The fiber optic amplifier according to claim 4, characterized in that, The filtering module includes at least one filter, which is a tunable optical filter (TOF) or a gain-flattening filter (GFF).

6. The fiber optic amplifier according to any one of claims 1 to 5, characterized in that, The photonic integrated chip includes a substrate. Along a direction perpendicular to the surface of the substrate, the photonic integrated chip includes a first waveguide layer and a second waveguide layer arranged in sequence. The second waveguide layer forms the second port, the third port, and the multiplexing module. The photonic integrated chip also includes a cladding layer covering the first waveguide layer and the second waveguide layer.

7. The fiber optic amplifier according to claim 6, characterized in that, The second waveguide layer, the first waveguide layer, and the substrate are arranged sequentially along a direction perpendicular to the surface of the substrate.

8. The fiber optic amplifier according to claim 7, characterized in that, A detector layer is included between the first waveguide layer and the second waveguide layer in a direction perpendicular to the surface of the substrate, or the detector layer is included between the first waveguide layer and the substrate in a direction perpendicular to the surface of the substrate, the detector layer forming a monitoring photodetector, the monitoring photodetector being used to detect the output optical power of the fiber amplifier.

9. The fiber optic amplifier according to claim 6, characterized in that, The first waveguide layer, the second waveguide layer, and the substrate are arranged sequentially along a direction perpendicular to the surface of the substrate.

10. The fiber optic amplifier according to claim 9, characterized in that, The photonic integrated chip further includes a detector layer, and the detector layer, the first waveguide layer, the second waveguide layer and the substrate are arranged in sequence along a direction perpendicular to the surface of the substrate. The detector layer forms a monitoring photodetector, which is used to detect the output optical power of the fiber amplifier.

11. The fiber optic amplifier according to any one of claims 6 to 10, characterized in that, The first waveguide layer forms a filter module, an adjustable optical attenuator, an optical splitter, and the first port; or, a portion of the filter module, the adjustable optical attenuator, the optical splitter, and the first port is formed by the first waveguide layer, and another portion is formed by the second waveguide layer.

12. The fiber optic amplifier according to any one of claims 1 to 5, characterized in that, The photonic integrated chip includes a substrate, a cladding layer, and a detector layer. The substrate surface includes a waveguide layer, which forms the multiplexing module, the first port, the second port, and the third port. The cladding layer covers the waveguide layer, and the cladding surface includes the detector layer, which forms a monitoring photodetector. The monitoring photodetector is used to detect the output optical power of the fiber amplifier, and the monitoring photodetector is bonded to the surface of the photonic integrated chip.

13. The fiber optic amplifier according to claim 12, characterized in that, Within the cladding, and located between the detector layer and the waveguide layer, a coupling module is further included. The coupling module is used to couple the monitoring light from the waveguide layer to the monitoring photodetector. The monitoring photodetector is used to detect the output optical power of the fiber amplifier based on the monitoring light.

14. The fiber optic amplifier according to any one of claims 1 to 13, characterized in that, The first port, the second port, and the third port are all edge couplers (ECs).

15. A light emitting module, characterized in that, The system includes a light source, a photonic integrated chip, a pump laser, and a gain medium. The photonic integrated chip includes an optical modulator and a multiplexing module. The optical modulator is connected to a first port of the photonic integrated chip via a first optical waveguide. The optical modulator is connected to the multiplexing module via a second optical waveguide. The multiplexing module is connected to a second port of the photonic integrated chip via a third optical waveguide. The second port is connected to the pump laser. The multiplexing module is connected to a third port of the photonic integrated chip via a fourth optical waveguide. The third port is connected to the gain medium. The optical modulator is used to modulate a first optical signal from the first port to obtain a modulated optical signal and transmit the modulated optical signal to the multiplexing module. The multiplexing module is used to receive pump light from the pump laser and combine the modulated optical signal and the pump light to obtain a second optical signal. The multiplexing module is also used to transmit the second optical signal to the gain medium. The gain medium is used to amplify the optical power of the modulated optical signal based on the pump light to obtain a third optical signal.

16. An optical transmitter, characterized in that, The device includes a processor, a driver, and an optical emission module as described in claim 15, wherein the processor, the driver, and the optical modulator are connected in sequence, the processor is used to send an electrical signal to the driver, the driver is used to transmit the amplified electrical signal to the optical modulator, the light source is used to transmit a first optical signal to the optical modulator, and the optical modulator is used to modulate the amplified electrical signal onto the first optical signal to obtain the modulated optical signal.

17. An optical receiving module, characterized in that, The device includes a photonic integrated chip, a pump laser, and a gain medium. The photonic integrated chip includes a multiplexing module and a detector. The multiplexing module is connected to a first port of the photonic integrated chip via a first optical waveguide. The multiplexing module is connected to a second port of the photonic integrated chip via a second optical waveguide. The second port is connected to the pump laser. The multiplexing module is connected to a third port of the photonic integrated chip via a third optical waveguide. The third port is connected to the gain medium. The detector is connected to a fourth port of the photonic integrated chip via a fourth optical waveguide. The fourth port is connected to the gain medium. The multiplexing module is used to receive a first optical signal from the first port and a pump light from the pump laser, and to combine the first optical signal and the pump light to obtain a second optical signal. The multiplexing module is also used to transmit the second optical signal to the gain medium, the gain medium is used to amplify the optical power of the first optical signal based on the pump light to obtain a third optical signal, and to transmit the third optical signal to the detector. The detector is used to perform photoelectric conversion on the third optical signal to obtain an electrical signal.

18. An optical receiver, characterized in that, It includes a processor and an optical receiving module as described in claim 17, wherein the processor is electrically connected to the detector, and the detector is used to send the electrical signal to the processor.

19. A radar, characterized in that, It includes a processor and an optical emitting module connected to the processor, the optical emitting module as described in claim 15; The processor is used to send detection electrical signals to the optical emitting module; The optical emission module is used to process the detection electrical signal into output light, and the output light is used to detect relevant information of the target object.

20. A radar, characterized in that, It includes a processor and an optical receiving module connected to the processor, the optical receiving module as described in claim 17; The optical receiving module is used to receive the first optical signal reflected by the target object and send the electrical signal to the processor. The processor is used to detect relevant information of the target object based on the electrical signal.

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