Laser chip, optical transmitter, optical transceiver and optical communication equipment

Abstract

The embodiment of the invention discloses a laser chip, an optical transmitter, an optical transceiver and optical communication equipment, relates to the field of laser chips, and solves the problem that a three-mode coexisting optical transceiver is large in size. The laser chip includes a substrate, and at least two laser modules both disposed on the substrate. The plurality of laser modules are respectively used for emitting a plurality of optical signals with different central wavelengths. Moreover, at least one laser module comprises a laser and a modulator, and the laser is connected with the modulator. The modulator is located on the light emitting side of the laser. The modulator is used for modulating laser output by the laser to generate a modulated optical signal. According to the laser chip, optical signals of various communication protocols can be sent, and the integration level of the laser chip is improved. For the optical transceiver device which needs to transmit and receive optical signals of various communication protocols, only one or a few laser chips in the embodiment of the invention are adopted, so that the optical transceiver device can adopt an SFP packaging mode, and the packaging size is relatively small.

Description

Technical Field

[0001] The present application relates to the technical field of laser chips, and in particular to a laser chip, an optical transmitter, an optical transceiver device and an optical communication device. Background Art

[0002] In the nearly 20 years of evolution of PON (passive optical network) optical networks, two generations of products, GPON (gigabit-capable PON) and 10G PON (10Gbit / s PON, 10Gbit passive optical network), have been commercialized, achieving the leap from 100M to 1G network. With the continuous increase in demand for optical networks, 50G PON (50Gbit / s PON, 50000Gbit passive optical network) products have also appeared in the industry.

[0003] With the deployment of 50G PON applications, it is necessary to set up 2.5G, 10G, and 50G three-mode coexisting optical transceivers on the optical line terminal (OLT) side to meet signal transmission requirements. The optical transceiver includes three optical transmitters and three optical receivers, and the three optical transmitters are used to transmit optical signals of the GPON communication protocol, the 10G PON communication protocol, and the 50G PON communication protocol, respectively. The three optical receivers are used to receive optical signals of the GPON communication protocol, the 10G PON communication protocol, and the 50G PON communication protocol, respectively. The size of the optical transceiver is obviously larger, and it is difficult to package the three optical transmitters and three optical receivers using a small form pluggable (SFP) packaging method. Only a quad small form puggable (QSFP) packaging method can be used, which makes the size of the optical transceiver larger. As a result, the size of the mainboard of the optical communication equipment such as the switch to which the optical transceiver is connected is increased. Summary of the invention

[0004] The embodiments of the present application provide a laser chip, an optical transmitter, an optical transceiver device and an optical communication device, which solve the problem of large size of existing optical transceiver devices with three modes coexisting.

[0005] In order to achieve the above objectives, this application adopts the following technical solutions:

[0006] In the first aspect, an embodiment of the present application provides a laser chip. The laser chip includes a substrate and two or more laser modules. For ease of explanation, it is referred to as "multiple laser modules" below. Among them, multiple laser modules are arranged on the substrate and are respectively used to emit lasers of multiple different central wavelengths. Therefore, compared with the prior art, the laser chip of the embodiment of the present application integrates multiple laser modules on the same substrate, and the multiple laser modules can respectively emit lasers of multiple different central wavelengths, so as to meet the needs of sending optical signals of multiple communication protocols. In an optical transceiver device, only one or a small number of laser chips of the embodiment of the present application can be used to realize the sending of optical signals of multiple communication protocols without using multiple laser chips. The laser chip of the embodiment of the present application has a high degree of integration. For an optical transceiver device that needs to receive and transmit optical signals of multiple communication protocols, only one or a small number of laser chips of the embodiment of the present application can be used. One or a small number of laser chips can be respectively packaged as optical transmitters using coaxial packaging. Afterwards, due to the small number of optical transmitters, a smaller SFP packaging method can be used to package them as optical transceivers. The optical transceiver device has a small volume and a small number of optical transmitters, which reduces the complexity of integration and the packaging cost. In addition, considering the port density of the optical communication equipment, the size of the mainboard of the device such as the switch to which the optical transceiver device is plugged will also be reduced. At the same time, the input capacity and output capacity of the switch are also improved. In addition, one or more laser modules in the embodiment of the present application include a laser and a modulator, and the laser is connected to the modulator. The modulator is located on the light output side of the laser, and the modulator is used to modulate the laser output by the laser to generate a modulated optical signal. Therefore, the laser of the embodiment of the present application has a high modulation speed, low chirp, few sidebands generated by modulation, low modulation distortion, high extinction ratio, can realize a variety of modulation code types and formats, and realize the modulation of high-speed signals. For example, modulation of 50G PON, 10G PON and GPON signals is realized.

[0007] Based on the structure of the above laser, since the band gap of the long-wavelength quantum well material is narrower in the semiconductor laser, it will absorb the high-energy photons emitted by the short-wavelength quantum well material. Therefore, in the embodiment of the present application, the light emission directions of multiple laser modules are the same, and multiple laser modules are connected and arranged in sequence from long to short along the central wavelength. That is, the central wavelengths of multiple laser modules decrease successively along the laser transmission direction, which can reduce the absorption of short-wavelength high-energy photons and reduce the signal crosstalk problem.

[0008] In some embodiments of the present application, the multiple laser modules in the above-mentioned laser chip include a first laser module and a second laser module, and the first laser module is used to emit a laser with a central wavelength of 1577nm. That is, the first laser module can convert the modulated electrical signal received at a rate of 10Gbps into a modulated optical signal with a central wavelength of 1577nm (wavelength of 1575-1580nm) for transmission, thereby transmitting the signal of the 10G PON protocol. The second laser module is used to emit a laser with a central wavelength of 1342nm. That is, the second laser module can convert the modulated electrical signal received at a rate of 50Gbps into a modulated optical signal with a central wavelength of 1342nm (wavelength of 1340-1344nm) for transmission.

[0009] Based on the above embodiments, in some embodiments of the present application, the above-mentioned first laser module includes a first laser and a first modulator, and the first laser is connected to the first modulator. The first modulator is arranged on the light output side of the first laser. In addition, the first modulator is used to modulate the laser output by the first laser to output a modulated optical signal. The above-mentioned second laser module includes a second laser and a second modulator, and the second laser is connected to the modulator. The second modulator is arranged on the light output side of the second laser. In addition, the second modulator is used to modulate the laser output by the second laser to output a modulated optical signal. Both the first laser module and the second laser module have the advantages of high modulation speed, low chirp, few sidebands generated by modulation, low modulation distortion, high extinction ratio, and realization of multiple modulation code types and formats. In addition, in order to ensure the performance of the modulator in the laser chip, the optimal absorption wavelength of the modulator also needs to decrease in sequence along the laser transmission direction.

[0010] In addition to the above-mentioned laser with an external modulator, the laser chip of the embodiment of the present application may also include a directly modulated laser, that is, the laser module includes a directly modulated laser, which can directly adjust the laser emitted by the laser. For example, in some embodiments of the present application, the above-mentioned multiple laser modules also include a third laser module, and the third laser module includes a third laser, and the third laser is a directly modulated laser. The third laser has the advantages of fast response speed, wide power adjustment range, simple structure, and low cost. For example, the third laser is used to emit a modulated optical signal with a central wavelength of 1490nm. That is, the third laser module can convert the received modulated electrical signal at a rate of 2.5Gbps into a modulated optical signal with a central wavelength of 1490nm (wavelength of 1480~1490nm) for emission.

[0011] Furthermore, in order to reduce the backward crosstalk of the previous short-wavelength light source, in some embodiments of the present application, the laser chip further includes a reflector, which is disposed between two adjacent laser modules. Furthermore, the reflector is used to reflect the laser emitted by one of the two adjacent laser modules with a shorter emission center wavelength toward the other laser module. Thus, the laser emitted by the previous laser module is prevented from crosstalking toward the next laser module.

[0012] Based on the above laser chip, in some embodiments of the present application, the above reflective device may be a Bragg reflector. It should be noted that two adjacent laser modules may be connected via a waveguide. Therefore, the Bragg reflector may be fabricated in the waveguide to form a waveguide including the Bragg reflector. The waveguide including the Bragg reflector may not only realize the connection between the two laser modules, but also reflect the light beam emitted by the laser module with a shorter central wavelength in the two adjacent laser modules toward the laser module with a longer central wavelength, thereby reducing the signal crosstalk problem.

[0013] Alternatively, it is possible to directly add no voltage or reverse bias voltage to the connecting waveguide between the two laser modules, and to reflect the light beam emitted by the laser module with a shorter central wavelength among the two adjacent laser modules back to the laser module with a longer central wavelength, thereby reducing the signal crosstalk problem.

[0014] In some scenarios, such as PON networks, the laser chip is required to have a higher modulated output power. Therefore, in some embodiments of the present application, the above-mentioned laser module also includes a first optical amplifier, and the first optical amplifier is located on the light output side of the modulator in the same laser module. In addition, the first optical amplifier is used to amplify the laser modulated by the modulator and then output it. Each laser module in the laser chip of the embodiment of the present application may include the above-mentioned first optical amplifier, so as to amplify the modulated laser of each laser module and then output it.

[0015] Alternatively, in some other embodiments of the present application, the laser chip further includes a second optical amplifier, which is located on the light output path of the multiple laser modules. Furthermore, the second optical amplifier is used to amplify the multiple lasers emitted by the multiple laser modules and then output them. Therefore, the frequency of the second optical amplifier is wider than that of the first optical amplifier. Thus, the second optical amplifier can amplify the power of the lasers emitted by the multiple laser modules. There are fewer devices in the laser chip and the structure is simpler.

[0016] It should be noted that when making the above-mentioned laser chip, how to make multiple laser modules on the same substrate is one of the most critical steps. In some embodiments of the present application, the above-mentioned substrate has a first surface. The laser includes a laser quantum well layer, and the modulator includes a modulator quantum well layer. The laser quantum well layer of the laser in the multiple laser modules and the modulator quantum well layer of the modulator are both arranged on the first surface of the substrate and are arranged in the same layer. Moreover, the structure and material of the laser quantum well layer in the same laser module are the same as the structure and material of the modulator quantum well layer. Therefore, the laser quantum well layer and the modulator quantum well layer in the same laser module can be made at the same time, which is convenient for realizing the series integration of devices in the laser module, reducing the insertion loss between different semiconductor devices, and improving the light output power of the laser chip.

[0017] In some examples of the present application, the structure of the laser quantum well layer and the structure of the modulator quantum well layer in the same laser module may also be made of different materials, and the present application does not impose any limitation on this.

[0018] Through precise optimization of the docking process between two adjacent laser modules, the series integration of different materials of the laser quantum well layer and the modulator quantum well layer in multiple laser modules can be achieved, and the docking interface can be precisely optimized and controlled to reduce passive insertion loss and increase optical power.

[0019] Furthermore, the lasers in the above-mentioned laser modules may all be electro-optically modulated lasers (external modulation laser, EML). Therefore, in some embodiments of the present application, the above-mentioned substrate has a second surface opposite to the first surface. The above-mentioned laser also includes a first laser electrode layer and a second laser electrode layer, and the first laser electrode layer is arranged on the side of the laser quantum well layer away from the substrate. The modulator includes a first modulator electrode layer and a second modulator electrode layer, and the first modulator electrode layer is located on the side of the modulator quantum well layer away from the substrate. The first laser electrode layer of the laser in multiple laser modules and the first modulator electrode layer of the modulator are of the same layer and material, and are insulated and isolated. Thus, the first laser electrode layer of the laser in multiple laser modules and the first modulator electrode layer of the modulator can be made by the same patterning process, and the process is relatively simple. Furthermore, the first laser electrode layer of the laser in multiple laser modules and the first modulator electrode layer of the modulator can be electrically isolated by etching, ion implantation, etc. to achieve the purpose of insulation.

[0020] The second laser electrode layer and the second modulator electrode layer can be both arranged on the second surface of the substrate, and the second laser electrode layer of the lasers in the multiple laser modules and the second modulator electrode layer of the modulator are of the same layer and material, and are interconnected. That is, a whole surface electrode layer is directly made on the second surface of the substrate, and the electrode layer is the second laser electrode layer and the second modulator electrode layer of the multiple laser modules, and the process is more convenient. The electrode layer is a common electrode layer, which can be used as the second laser electrode layer of the lasers in the multiple laser modules and the second modulator electrode layer of the modulator. Alternatively, the second laser electrode layer and the second modulator electrode layer can also be both arranged on the first surface of the substrate. The second laser electrode layer and the second modulator electrode are coplanar electrodes. This application does not impose any restrictions on this.

[0021] In addition, the laser can be a distributed feedback (DFB), distributed reflector (DBR) or other types of narrow line width lasers. Therefore, in some embodiments of the present application, the laser further includes a grating, which is disposed on a side of the laser quantum well layer away from the substrate.

[0022] In the second aspect, the embodiment of the present application also includes an optical transmitter. The optical transmitter includes the laser chip and a tube shell described in the above embodiment, and the tube shell can encapsulate the laser chip. Since the laser chip in the optical transmitter of the embodiment of the present application has the same structure as the laser chip described in the above embodiment, both can solve the same technical problems and obtain the same technical effects, and will not be described in detail here.

[0023] Furthermore, in some embodiments of the present application, the tube shell in the above optical transmitter is a coaxial package (transistor outline, TO) tube shell. Therefore, the volume of the optical transmitter is small. In some other embodiments of the present application, the tube shell in the above optical transmitter is a box-type (BOX) package tube shell.

[0024] On the third aspect, the embodiment of the present application also includes an optical transceiver device. The optical transceiver device includes the above-mentioned optical transmitter and one or more optical receiving devices, and the optical transmitter is used to transmit optical signals of two or more different communication protocols. Optical signals of different communication protocols have different central wavelengths. One or more optical receiving devices are used to receive optical signals of two or more different communication protocols. Thus, the transceiver and receiver of optical signals of two or more different communication protocols are realized. Since the optical transmitter in the optical transceiver device of the embodiment of the present application has the same structure as the optical transmitter described in the above embodiment, both can solve the same technical problems. The optical transceiver device encapsulates the TO tube shell, thermoelectric cooler (TEC), lens, beam splitter and other components required, the number of optical transmitters is reduced, the internal device structure is simplified, and the size is reduced.

[0025] Therefore, in some embodiments of the present application, the optical transmitter and one or more optical receiving devices are integrated into a miniaturized pluggable package. The optical transceiver device is relatively small in size.

[0026] In a fourth aspect, the embodiment of the present application also includes an optical communication device. The optical communication device may be a PON device, such as an optical module in an optical line terminal device. The optical communication device includes a circuit board and the optical transceiver device described in the above embodiment. The optical transceiver device is electrically connected to the circuit board. Since the optical transceiver device in the optical communication device of the embodiment of the present application has the same structure as the optical transceiver device described in the above embodiment, both can solve the same technical problems and obtain the same technical effects, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to illustrate the technical solution of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be described below.

[0028] Figure 1 It is a structural schematic diagram of an optical transceiver device in the related art;

[0029] Figure 2 This is a schematic diagram of the structure of the first laser chip in the embodiment of the present application;

[0030] Figure 3 This is a schematic diagram of the structure of the second laser chip in the embodiment of the present application;

[0031] Figure 4 This is a schematic diagram of the structure of the third laser chip in the embodiment of the present application;

[0032] Figure 5 This is a schematic diagram of the structure of the fourth laser chip of the embodiment of the present application;

[0033] Figure 6This is a schematic diagram of the structure of a laser chip with a reflective device according to an embodiment of the present application;

[0034] Figure 7 This is a schematic structural diagram of a laser chip having a first optical amplifier according to an embodiment of the present application;

[0035] Figure 8 This is a schematic diagram of the structure of a laser chip with a second optical amplifier according to an embodiment of the present application;

[0036] Fig. 9 This is a schematic diagram of the hierarchical structure of the laser and substrate in the laser chip of the embodiment of the present application;

[0037] Fig.10 This is a schematic diagram of the hierarchical structure of the modulator and substrate in the laser chip of the embodiment of the present application;

[0038] Fig.11 This is a schematic diagram of the hierarchical structure of the laser chip according to an embodiment of the present application;

[0039] Fig.12 A schematic diagram of the hierarchical structure of a laser with a ridge waveguide according to an embodiment of the present application;

[0040] Fig.13 A schematic diagram of the hierarchical structure of a laser chip with a grating according to an embodiment of the present application;

[0041] Fig.14 A schematic diagram of the hierarchical structure of a laser chip having a high-reflection film layer and an anti-reflection film layer according to an embodiment of the present application;

[0042] Fig.15 A schematic diagram of the hierarchical structure of a laser chip with a reflective device according to an embodiment of the present application;

[0043] Fig.16 A schematic diagram of the hierarchical structure of a laser chip having a first optical amplifier according to an embodiment of the present application;

[0044] Fig.17 This is a schematic diagram of the structure of an optical transmitter using coaxial packaging in an embodiment of the present application;

[0045] Fig.18 This is a schematic diagram of the structure of an optical transmitter using a box-type package in an embodiment of the present application;

[0046] Fig.19 This is a schematic diagram of the structure of the optical transceiver device according to an embodiment of the present application.

[0047] Figure Number:

[0048] 100-optical transceiver device; 10-optical transmitter; 1-laser chip; 11-substrate; 111-first surface; 112-second surface; 12-laser module; 12a-first laser module; 12b-second laser module; 13c-third laser module; 121-laser; 121a-first laser; 121b-second laser; 121c-third laser; 1211-N-type laser waveguide layer; 1212-laser quantum well layer; 1213-P-type laser waveguide layer; 1214-first Laser electrode layer; 1215-second laser electrode layer; 1216-grating; 122-modulator; 122a-first modulator; 122b-second modulator; 1221-N-type modulator waveguide layer; 1222-modulator quantum well layer; 1223-P-type modulator waveguide layer; 1224-first modulator electrode layer; 1225-second modulator electrode layer; 123-first optical amplifier; 13-reflection device; 14-second optical amplifier; 15-high reflection film layer; 16-anti-reflection film layer; 2-tube shell. DETAILED DESCRIPTION

[0049] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings.

[0050] In the following, the terms "first", "second", etc. are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0051] In addition, in the present application, directional terms such as "up", "down", "left", "right", "horizontal" and "vertical" are defined relative to the orientation of the components in the drawings. It should be understood that these directional terms are relative concepts. They are used for relative description and clarification, and they may change accordingly according to the changes in the orientation of the components in the drawings.

[0052] In this application, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense. For example, "connection" can refer to the connection of mechanical structure or physical structure. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be directly connected or indirectly connected through an intermediate medium. It can also be understood as the physical contact and electrical conduction of components, and it can also be understood as the form in which different components in the circuit structure are connected through physical lines such as PCB copper foil or wires that can transmit electrical signals.

[0053] 50G PON technology can provide 10G access capabilities, so it is widely used in 8K, extended reality (XR), industrial Internet, industry digitalization and other fields. With the application and deployment of 50G PON, it will be necessary to set up 2.5G PON, 10GPON, and 50G PON three-mode coexisting optical transceiver devices on the optical line terminal side to meet signal transmission requirements.

[0054] However, if the optical transceiver device 100 includes three laser chips and three detector chips, the three laser chips are used to transmit optical signals of the GPON communication protocol, the 10G PON communication protocol, and the 50G PON communication protocol, respectively. Figure 1 As shown, three laser chips are respectively packaged as optical transmitters 10 using TO packaging. Three detector chips are respectively used to receive optical signals of GPON communication protocol, 10G PON communication protocol and 50G PON communication protocol. The three detector chips can also be respectively packaged as optical receivers 20 using TO packaging. Multiple TO-packaged optical transmitters 10 and multiple TO-packaged optical receivers 20 can only be packaged using a larger four-channel small pluggable packaging method or a more expensive box packaging method, but cannot be packaged using a smaller and less expensive small pluggable method.

[0055] Therefore, in order to solve this problem, the embodiment of the present application proposes a laser chip 1 with higher integration, which reduces the number of components in the optical transceiver device 100, thereby reducing the size of the optical transceiver device. Figure 2 The laser chip 1 includes a substrate 11 and two or more laser modules 12. For ease of explanation, "two or more laser modules 12" will be referred to as "multiple laser modules 12" below. The multiple laser modules 12 are all arranged on the substrate 11. It should be noted that being arranged on the substrate 11 means that the film layer structure in the multiple laser modules 12 can be arranged on the surface of the substrate 11, but must not be arranged on the upper surface of the substrate 11. It can be understood that the laser module 12 includes a laser 121. The multiple laser modules 12 are respectively used to emit lasers with multiple different central wavelengths.

[0056] Therefore, the laser chip 1 of the embodiment of the present application is integrated with multiple laser modules 12 on the same substrate, and the multiple laser modules 12 can respectively emit lasers of multiple different central wavelengths to meet the needs of sending optical signals of multiple communication protocols. In the optical transceiver device, only one or a small number of laser chips 1 of the embodiment of the present application can be used to realize the sending of optical signals of multiple communication protocols, without using multiple laser chips 1, and the integration of the laser chip 1 of the embodiment of the present application is relatively high. For the optical transceiver device 100 that needs to receive and transmit optical signals of multiple communication protocols, only one or a small number of laser chips 1 of the embodiment of the present application can be used. One or a small number of laser chips 1 are respectively packaged as optical transmitters 10 using TO. Afterwards, since the number of optical transmitters 10 is small, a smaller SFP packaging method can be used to package it into an optical transceiver device 100. The optical transceiver device 100 is small in size and has a small number of optical transmitters 10, which reduces the complexity of integration and also reduces the packaging cost. In addition, considering the port density of optical communication equipment, the size of the motherboard of the device such as the switch to which the optical transceiver device 100 is plugged will also be reduced. At the same time, the input and output capacities of the switch are also increased.

[0057] Based on the above structure, the laser 121 in the multiple laser modules 12 can be a directly modulated laser or a laser 121 with an external modulator. That is, the laser module 12 includes a laser 121 and a modulator 122 connected to each other, and the series connection of the two can be achieved through a precise optimization docking process. The modulator 122 is located on the light output side of the laser 121. The modulator 122 is used to modulate the laser output by the laser 121 to generate a modulated optical signal. In order to meet the needs of high-speed communications such as 10GPON and 50G PON, at least one laser module 12 in the multiple laser modules 12 of the embodiment of the present application is the above-mentioned laser module 12 including the laser 121 and the modulator 122. Therefore, the laser module 12 can emit optical signals required by the 50G PON communication protocol or the 10G PON communication protocol. At the same time, the above-mentioned laser module 12 with external modulator also has the advantages of high modulation speed, low chirp, few sidebands generated by modulation, low modulation distortion, high extinction ratio, realization of various modulation code types and formats, and realization of modulation of high-speed signals.

[0058] For ease of understanding, the 50G PON protocol, 10G PON protocol and GPON protocol are briefly described. The 50G PON protocol includes receiving a modulated optical signal with a rate of 50Gbps and a wavelength of 1284-1288nm, converting the received modulated electrical signal with a rate of 50Gbps into a modulated optical signal with a center wavelength of 1342nm (wavelength of 1340-1344nm) for transmission. The 10G PON protocol includes receiving a modulated optical signal with a rate of 10Gbps and a wavelength of 1260-1280nm, converting the received modulated electrical signal with a rate of 10Gbps into a modulated optical signal with a center wavelength of 1577nm (wavelength of 1575-1580nm) for transmission. The GPON protocol includes receiving a modulated optical signal with a rate of 1.25 Gbps and a wavelength of 1290-1330 nm, converting the received modulated electrical signal with a rate of 2.5 Gbps into a modulated optical signal with a central wavelength of 1490 nm (wavelength of 1480-1490 nm) for transmission.

[0059] Moreover, in some embodiments of the present application, the light emitting directions of the multiple laser modules 12 are the same. The above-mentioned multiple laser modules 12 can be connected and arranged in sequence. For example, two adjacent laser modules 12 are connected by a waveguide. Considering that in semiconductor lasers, the band gap of long-wavelength quantum well materials is narrower, and it will absorb high-energy photons emitted by short-wavelength quantum well materials. Therefore, in some embodiments of the present application, along the light emitting direction of the laser module 12, the central wavelengths of the multiple laser modules 12 decrease successively. Thereby, the absorption of short-wavelength high-energy photons is reduced, and the signal crosstalk problem is reduced.

[0060] For example, Figure 3As shown, the multiple laser modules 12 in the laser chip 1 include a first laser module 12a, a second laser module 12b and a third laser module 13c. The first laser module 12a, the third laser module 13c and the second laser module 12b are arranged in sequence along the first direction P. The light emitting direction of the first laser module 12a, the light emitting direction of the third laser module 13c and the light emitting direction of the second laser module 12b are also the first direction P. In addition, the center wavelength of the first laser module 12a, the center wavelength of the third laser module 13c and the center wavelength of the second laser module 12b decrease in sequence. For example, the first laser module 12a is used to convert a modulated electrical signal with a received rate of 10Gbps into a modulated optical signal with a central wavelength of 1577nm (wavelength of 1575-1580nm) for transmission. The second laser module 12b is used to convert a modulated electrical signal with a received rate of 50Gbps into a modulated optical signal with a central wavelength of 1342nm (wavelength of 1340-1344nm) for transmission. The third laser module 13c is used to convert the received modulated electrical signal at a rate of 2.5 Gbps into a modulated optical signal with a central wavelength of 1490 nm (wavelength of 1480-1490 nm) for transmission. Thus, the laser chip 1 can simultaneously transmit the optical signals required by the 50G PON protocol, 10G PON protocol or GPON protocol.

[0061] Since the first laser module 12a is used for high-speed signal transmission of the 10G PON communication protocol, in some embodiments of the present application, the first laser module 12a includes a first laser 121a and a first modulator 122a, and the first laser 121a is connected to the first modulator 122a. The first modulator 122a is arranged on the light-emitting side of the first laser 121a. In addition, the first modulator 122a is used to modulate the laser output by the first laser 121a to output a modulated optical signal. Similarly, the second laser module 12b is used for high-speed signal transmission of the 50G PON protocol, so the second laser module 12b includes a second laser 121b and a second modulator 122b, and the second laser 121b is connected to the second modulator 122b. The second modulator 122b is arranged on the light-emitting side of the second laser 121b. In addition, the second modulator 122b is used to modulate the laser output by the second laser 121b to output a modulated optical signal. The first laser module 12a and the second laser module 12b both have the advantages of high modulation speed, low chirp, few sidebands generated by modulation, low modulation distortion, high extinction ratio, and realization of multiple modulation code types and formats.

[0062] The third laser module 13c is used for signal transmission of the GPON protocol, and the signal transmission speed is relatively slow. Therefore, in some embodiments of the present application, the third laser module 13c includes a third laser 121c, and the third laser 121c is a directly modulated laser. The third laser 121c has the advantages of fast response speed, wide power adjustment range, simple structure, low cost, etc.

[0063] It should be noted that, in order to ensure the performance of the modulator 122 in the laser chip 1, the optimal absorption wavelengths of the modulators 122 in the above-mentioned multiple laser modules 12 also need to decrease in sequence along the laser transmission direction. In addition, in some embodiments of the present application, the multiple laser modules 12 in the laser chip 1 may also only include Figure 3 Any two of the first laser module 12a, the second laser module 12b and the third laser module 13c. Figure 4 As shown, the plurality of laser modules 12 only include the first laser module 12a and the third laser module 13c. Figure 5 As shown, the plurality of laser modules 12 only include the second laser module 12b and the third laser module 13c.

[0064] Furthermore, in order to further reduce the crosstalk of the short-wavelength light source emitted by the previous laser module to the next laser module ("front" and "back" are based on the laser emission direction), in some embodiments of the present application, the laser chip 1 further includes: Figure 6 The reflective device 13 shown is arranged between two adjacent laser modules 12. Taking the two laser modules 12 as an example, the first laser module 12a and the second laser module 12b, the first laser module 12a emits a laser with a central wavelength of 1577nm, and the second laser module 12b emits a laser with a central wavelength of 1342nm. The second laser module 12b is located on the light output path of the first laser module 12a. That is, the first laser module 12a is the next-level laser module 12 of the second laser module 12b. The second laser module 12b is the previous-level laser module 12 of the first laser module 12a. The reflective device 13 is used to reflect the laser emitted by the second laser module 12b toward the first laser module 12a back, so that the laser emitted by the second laser module 12b can only emit laser forward (i.e., along the first direction). Thereby, the laser emitted by the second laser module 12b is prevented from crosstalking toward the first laser module 12a.

[0065] Among them, in some embodiments of the present application, the above-mentioned reflective device 13 can be a Bragg reflector. It should be noted that two adjacent laser modules 12 can be connected by a waveguide. Therefore, the Bragg reflector can be made in the waveguide connecting the two adjacent laser modules 12. The waveguide including the Bragg reflector can not only realize the connection of the two laser modules 12, but also reflect the light beam emitted by the laser module 12 with a shorter emission center in the two adjacent laser modules 12 toward the laser module 12 with a longer central wavelength, thereby reducing the signal crosstalk problem.

[0066] In addition, in the present application, by not applying voltage or adding reverse bias voltage to the connecting waveguide between the two laser modules 12, the function of reflecting the laser emitted by the second laser module 12b toward the first laser module 12a can be achieved, thereby reducing the signal crosstalk problem.

[0067] In some scenarios, such as PON networks, the laser chip 1 is required to have a higher modulated output power. Therefore, in some embodiments of the present application, the laser module 12 further includes: Figure 7 The first optical amplifier 123 shown is located at the light output side of the modulator 122 in the same laser module 12. In addition, the first optical amplifier 123 is used to amplify the laser modulated by the modulator 122 and output it. It can be understood that each laser module 12 in the laser chip 1 of the embodiment of the present application may include the above-mentioned first optical amplifier 123, so as to amplify the laser modulated by each laser module 12. Alternatively, only some laser modules 12 may include the above-mentioned first optical amplifier 123, so as to amplify the modulated optical signal of the laser module that needs a higher modulated output power.

[0068] In addition, in some other embodiments of the present application, the laser chip 1 further includes: Figure 8 The second optical amplifier 14 shown is located on the light output path of the above-mentioned multiple laser modules 12. In addition, the second optical amplifier 14 is used to amplify the multiple lasers emitted by the multiple laser modules 12 and then output them. Therefore, the frequency of the second optical amplifier 14 is wider than the frequency of the first optical amplifier 123. Thus, the second optical amplifier 14 can amplify the power of the lasers emitted by the multiple laser modules 12. The laser chip 1 has fewer devices and a simpler structure.

[0069] The above mainly introduces the device composition of the laser chip 1 in the embodiment of the present application. Among them, the laser 121 in the above-mentioned laser chip 1 can be various types of lasers. For example, the lasers 121 in multiple laser modules 12 can all be photoelectric modulated lasers. Different types of lasers 121 have different hierarchical structures. The following takes the example that the lasers 121 in multiple laser modules 12 are all photoelectric modulated lasers to briefly describe the specific hierarchical structure of the laser chip 1 in the embodiment of the present application.

[0070] The laser 121 in the laser module 12 of the embodiment of the present application can be formed by growing and / or doping a laser epitaxial structure on the substrate 11. Similarly, the modulator 122 can also be formed by growing and / or doping a modulator epitaxial structure on the substrate 11. In order to simplify the process flow, the laser 121 and the modulator 122 can also adopt the same or similar hierarchical structure.

[0071] For example, in some embodiments of the present application, Fig. 9 As shown, the laser 121 includes an N-type laser waveguide layer 1211, a laser quantum well layer 1212, a P-type laser waveguide layer 1213, a first laser electrode layer 1214 and a second laser electrode layer 1215. The substrate 11 includes a first surface 111 and a second surface 112 arranged opposite to each other. Specifically, the substrate 11 can be made of indium phosphide InP material. The N-type laser waveguide layer 1211, the laser quantum well layer 1212, the P-type laser waveguide layer 1213, and the first laser electrode layer 1214 are sequentially stacked on the first surface 111 of the substrate 11. The second laser electrode layer 1215 can be arranged on the second surface 112 of the substrate 11. Fig.10 The epitaxial structure of the modulator 122 shown is similar to the epitaxial structure of the laser 121 described above. Fig.10 As shown, the modulator 122 includes an N-type modulator waveguide layer 1221, a modulator quantum well layer 1222, a P-type modulator waveguide layer 1223, a first modulator 122a electrode layer and a second modulator electrode layer 1225. The N-type modulator waveguide layer 1221, the modulator quantum well layer 1222, the P-type modulator waveguide layer 1223, and the first modulator 122a electrode layer are sequentially stacked on the first surface 111 of the substrate 11. The second modulator electrode layer 1225 can be disposed on the second surface 112 of the substrate 11.

[0072] Among them, Fig.11As shown, the N-type laser waveguide layer 1211 and the N-type modulator waveguide layer 1221 can also be set in the same layer and the same material. Therefore, the N-type laser waveguide layer 1211 and the N-type modulator waveguide layer 1221 can be made in one process, and the process manufacturing is more convenient. For example, an N-type waveguide layer is grown or doped on the first surface 111 of the substrate 11. The N-type waveguide layer includes the N-type laser waveguide layer 1211 of the laser 121 in the multiple laser modules 12 and the N-type modulator waveguide layer 1221 of the modulator 122. That is to say, the N-type waveguide layer is a common N-type waveguide layer of the multiple laser modules 12.

[0073] It should be noted that "same layer" refers to a layer structure formed by using the same film-forming process to form a film layer for forming a specific pattern, and then using the same mask through a single patterning process. Depending on the specific pattern, the same patterning process may include multiple exposure, development or etching processes, and the specific patterns in the formed layer structure may be continuous or discontinuous, and these specific patterns may also be at different heights or have different thicknesses.

[0074] Continue to refer to Fig.11 , the above-mentioned laser quantum well layer 1212 and modulator quantum well layer 1222 can also be arranged in the same layer. Moreover, the structure of the laser quantum well layer 1212 and the structure of the modulator quantum well layer 1222 can be the same or different, and the present application does not impose any restrictions on this. In some embodiments of the present application, the structure of the laser quantum well layer 1212 in the same laser module 12 is the same as the structure of the modulator quantum well layer 1222. The material of the laser quantum well layer 1212 and the material of the modulator quantum well layer 1222 in the same laser module 12 can also be the same or different, and the present application does not impose any restrictions on this. For the example of using the laser quantum well layer 1212 and the modulator quantum well layer 1222 of the same material, the laser quantum well layer 1212 and the modulator quantum well layer 1222 in the same laser module 12 can be manufactured at the same time, which is convenient for realizing the series integration of devices in the laser module 12, reducing the insertion loss between different semiconductor devices, and improving the light output power of the laser chip 1.

[0075] For different laser modules 12, and laser quantum well layers 1212 and modulator quantum well layers 1222 of different materials in the same laser module 12, the series integration of multiple semiconductor devices of different materials can be achieved through precise optimization of the docking process. In addition, precise optimization and control of the docking interface of different materials can reduce passive insertion loss and improve optical power.

[0076] Similarly, the P-type laser waveguide layer 1213 and the P-type modulator waveguide layer 1223 can also be set in the same layer and the same material. Therefore, the P-type laser waveguide layer 1213 and the P-type modulator waveguide layer 1223 can be manufactured in one process, and the process manufacturing is more convenient. For example, a whole surface of a P-type waveguide layer is grown on the laser quantum well layer 1212 and the modulator quantum well layer 1222. The P-type waveguide layer includes the P-type laser waveguide layer of the laser 121 in the multiple laser modules 12 and the P-type modulator waveguide layer of the modulator 122. The P-type waveguide layer is a common waveguide layer for multiple laser modules 12.

[0077] It should be noted that the P-type laser waveguide layer 1213 may be Fig.12 The ridge waveguide structure shown may also be a buried heterojunction structure. A buried heterojunction structure refers to insulating materials such as indium phosphide covering both sides of the ridge waveguide. The P-type modulator waveguide layer 1223 may also be a ridge waveguide structure or a buried heterojunction structure.

[0078] Furthermore, in an embodiment of the present application, the above-mentioned first laser electrode layer 1214 and the first modulator electrode layer 1224 can be arranged in the same layer and the same material, and insulated and isolated. Therefore, the first laser electrode layer 1214 and the first modulator electrode layer 1224 are coplanar electrodes. The first laser electrode layer 1214 of the laser 121 and the first modulator electrode layer 1224 of the modulator 122 in the multiple laser modules 12 can be manufactured by the same patterning process, and the process flow is relatively simple. The first laser electrode layer 1214 of the laser 121 and the first modulator electrode layer 1224 of the modulator 122 in the multiple laser modules 12 can be electrically isolated by etching, ion implantation and other schemes to achieve the purpose of insulation.

[0079] For ease of understanding, in some embodiments of the present application, the patterning process may refer to a photolithography process, or a photolithography process and an etching step, and may also include printing, inkjet and other processes for forming a predetermined pattern; the photolithography process refers to a process for forming a pattern using a photoresist, a mask, an exposure machine, etc., including film formation, exposure, and development processes. The corresponding patterning process can be selected according to the structure formed in the present invention. Among them, the one-time patterning process in the embodiments of the present application is explained by taking the example of forming different exposure areas through a mask exposure process, and then performing multiple etching, ashing and other removal processes on the different exposure areas to finally obtain the expected pattern.

[0080] Return to reference Fig.11, the above-mentioned second laser electrode layer 1215 and second modulator electrode layer 1225 are both arranged on the second surface 112 of the substrate 11. That is, the second laser electrode layer 1215 and the second modulator electrode layer 1225 are also coplanar electrodes. In addition, the second laser electrode layer 1215 of the laser 121 and the second modulator electrode layer 1225 of the modulator 122 in the multiple laser modules 12 can be arranged in the same layer and the same material, and connected to each other. That is, a whole-surface electrode layer is directly made on the second surface 112 of the substrate 11. The whole-surface electrode layer includes the second laser electrode layer 1215 of the laser 121 and the second modulator electrode layer 1225 of the modulator 122 in the multiple laser modules 12. That is, the electrode layer is a common electrode layer, and the process of making the whole-surface electrode layer is more convenient.

[0081] It should be noted that the second laser electrode layer 1215 and the second modulator electrode layer 1225 can also be arranged on the first surface 111 of the substrate 11. The second laser electrode layer 1215 and the second modulator electrode layer 1225 are arranged in the same layer. Therefore, the second laser electrode layer 1215 and the second modulator electrode layer 1225 are also coplanar electrodes. The manufacturing process of the second laser electrode layer 1215 and the second modulator electrode layer 1225 of the laser 121 in the plurality of laser modules 12 is also relatively simple.

[0082] In addition, the laser 121 may be a distributed feedback laser, a distributed reflector laser, or any other type of narrow line width laser. Fig.13 The grating 1216 shown is arranged on the side of the laser quantum well layer 1212 away from the substrate 11. For example, the grating 1216 is located in the P-type laser waveguide layer in 1213, that is, buried by the waveguide material. The grating 1216 can further oscillate the laser to achieve a narrow line width.

[0083] Furthermore, the plurality of laser modules 12 in the laser chip 1 can be arranged in the same resonant cavity. Fig.14 As shown, in some embodiments of the present application, the laser chip 1 includes a high-reflection film (HR Film) 15 and an anti-reflection film (AR Film) 16. The high-reflection film 15 and the anti-reflection film 16 can be formed on both ends of the substrate 11, the waveguide layer, and the quantum well layer by, for example, vapor deposition. The high-reflection film 15 and the anti-reflection film 16 can reduce the threshold current of the laser chip 1, improve the output power and working life of the laser chip 1, and can also effectively protect the end faces of each semiconductor device. And, Fig.15Also shown is a laser chip 1 having a reflective element 13 as a Bragg reflection waveguide.

[0084] For the laser chip 1 having the first optical amplifier 123 or the second optical amplifier 14, the hierarchical structure of the first optical amplifier 123 or the hierarchical structure of the second optical amplifier 14 may be the same as or similar to the hierarchical structure of the laser 121. For example, Fig.16 As shown, the structure of the quantum well layer of the first optical amplifier 123 is the same as the structure of the laser quantum well layer 1212 of the laser 121. Therefore, it can be manufactured simultaneously with the various hierarchical structures of the laser 121, simplifying the process flow.

[0085] It should be noted that, in addition to the above-mentioned hierarchical structure, the above-mentioned laser 121 may also include other hierarchical structures such as a buffer layer, an ohmic contact layer, and a cladding layer, etc., and this application does not limit this. And, correspondingly, the modulator 122 may also include the above-mentioned buffer layer, an ohmic contact layer, and a cladding layer, etc., so that the manufacturing process of the laser 121 and the modulator 122 is more convenient.

[0086] The above mainly describes the hierarchical structure of the laser chip 1. In the application of the laser chip 1, the laser chip 1 can be integrated with other components to form a light emitter 10. Other components may include a tube shell, a lens, a base, a temperature control unit, a device housing, and other structures. Among them, the temperature control unit may be a thermoelectric cooler or a thermistor. In some examples, the tube shell 2 of the light emitter 10 is as follows: Fig.17 In other examples, the tube shell 2 of the optical transmitter 10 is as shown in FIG. Fig.18 The box package shown.

[0087] Furthermore, the optical transmitter 10 can also be combined with one or more optical receivers 20 to form an optical transceiver device 100. Fig.19 The optical transceiver device 100 includes the above-mentioned optical transmitter 10 and one or more optical receivers 20. The optical transmitter 10 is used to transmit optical signals of two or more different communication protocols. Optical signals of different communication protocols have different central wavelengths. One or more optical receivers 20 are used to receive optical signals of two or more different communication protocols. Thus, the transceiver of optical signals of two or more different communication protocols is realized. Since the optical transmitter 10 in the optical transceiver device 100 of the embodiment of the present application has the same structure as the optical transmitter 10 described in the above embodiment, both can solve the same technical problems.

[0088] Furthermore, since the number of optical transmitters 10 in the optical transceiver device 100 can be reduced, the number of components required for packaging, such as TO tube shells, thermoelectric coolers, lenses, beam splitters, etc., is reduced. Therefore, the structure of the optical transceiver device 100 is simplified and the volume is reduced.

[0089] The optical transceiver device 100 can be applied to various optical communication devices. The optical communication device can be a PON device, such as an optical module on an optical line terminal device. In addition, the optical module can be an onboard optical module or a pluggable optical module.

[0090] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A laser chip, characterized in that: include: substrate; At least two laser modules, both of which are arranged on the substrate and are respectively used to emit lasers with at least two different central wavelengths; at least one laser module includes a connected laser and a modulator, the modulator is located on the light output side of the laser and is used to modulate the laser output by the laser.

2. The laser chip according to claim 1, characterized in that: The light emitting directions of the at least two laser modules are the same, and the at least two laser modules are sequentially connected and arranged along the central wavelength in a descending order.

3. The laser chip according to claim 1 or 2, characterized in that: The laser chip further comprises: A reflective device is disposed between two adjacent laser modules and is used to reflect back the light beam emitted by one of the laser modules with a shorter emission center wavelength toward the other laser module.

4. The laser chip according to claim 3, characterized in that: The reflective device is a Bragg reflector.

5. The laser chip according to any one of claims 1 to 4, characterized in that: The at least two laser modules include: A first laser module, wherein the first laser module is used to emit a laser with a central wavelength of 1577 nm; A second laser module, wherein the second laser module is used to emit laser light with a central wavelength of 1342 nm.

6. The laser chip according to claim 5, characterized in that: The first laser module includes a first laser and a first modulator connected to each other, wherein the first modulator is arranged at the light output side of the first laser and is used to modulate the laser light output by the first laser; The second laser module includes a second laser and a second modulator connected to each other. The second modulator is arranged on the light-emitting side of the second laser and is used to modulate the second laser.

7. The laser chip according to any one of claims 1 to 6, characterized in that: The laser module also includes: The first optical amplifier is located at the light output side of the modulator in the same laser module and is used for amplifying and outputting the laser light modulated by the modulator.

8. The laser chip according to any one of claims 1 to 6, characterized in that: The laser chip further comprises: The second optical amplifier is located on the light output path of the at least two laser modules and is used for amplifying the multiple lasers emitted by the at least two laser modules and then outputting them.

9. The laser chip according to any one of claims 1 to 8, characterized in that: The substrate has a first surface; the laser includes a laser quantum well layer, and the modulator includes a modulator quantum well layer. The laser quantum well layer of the laser and the modulator quantum well layer of the modulator in the at least two laser modules are both arranged on the first surface of the substrate and are arranged in the same layer; the structure and material of the laser quantum well layer in the same laser module are the same as the structure and material of the modulator quantum well layer.

10. The laser chip according to claim 9, characterized in that: The substrate has a second surface opposite to the first surface; the laser also includes a first laser electrode layer and a second laser electrode layer, and the modulator includes a first modulator electrode layer and a second modulator electrode layer, the first laser electrode layer is arranged on a side of the laser quantum well layer away from the substrate, and the first modulator electrode layer is located on a side of the modulator quantum well layer away from the substrate; the first laser electrode layer of the laser and the first modulator electrode layer of the modulator in the at least two laser modules are of the same layer and material, and are insulated and isolated; the second laser electrode layer and the second modulator electrode layer are both arranged on the second surface of the substrate, and the second laser electrode layer of the laser and the second modulator electrode layer of the modulator in the at least two laser modules are of the same layer and material and are connected.

11. The laser chip according to claim 9 or 10, characterized in that: The laser also includes: A grating is arranged on a side of the laser quantum well layer away from the substrate.

12. A light transmitter, characterized in that: The laser chip according to any one of claims 1 to 11; A tube shell is used to package the laser chip.

13. The optical transmitter according to claim 12, characterized in that The tube shell is a coaxial packaging tube shell.

14. An optical transceiver device, characterized in that: include: The optical transmitter of claim 12 or 13, wherein the optical transmitter is used to transmit optical signals of at least two different communication protocols; At least one optical receiving device, the at least one optical receiving device is used to receive optical signals of at least two different communication protocols.

15. The optical transceiver device according to claim 14, characterized in that: The optical transmitter and the at least one optical receiving device are integrated into a miniaturized pluggable package.

16. An optical communication device, characterized in that: include: Circuit boards; The optical transceiver device described in claim 14 or 15 is electrically connected to the circuit board.

Images