WO2020155029A1

WO2020155029A1 - Semiconductor laser apparatus and manufacturing method therefor, and device

Info

Publication number: WO2020155029A1
Application number: PCT/CN2019/074207
Authority: WO
Inventors: 任正良; 黄利新; 操日祥
Original assignee: 华为技术有限公司
Priority date: 2019-01-31
Filing date: 2019-01-31
Publication date: 2020-08-06
Also published as: CN111903022A

Abstract

A semiconductor laser apparatus and a manufacturing method therefor, and a device. The semiconductor laser apparatus comprises: a first laser and a second laser, the first laser and the second laser being attached to the same substrate layer; an n electrode of the first laser and an n electrode of the second laser are mutually independent, and a p electrode of the first laser and a p electrode of the second laser are mutually independent; the current generated within the first laser forms a first current channel when a first signal is added to an electrode of the first laser, and the current generated within the second laser forms a second current channel when a second signal is added to an electrode of the second laser, the modulation of the first laser by the first signal and the modulation of the second laser by the second signal being mutually independent; the second laser comprises a cover layer, and the cover layer is used to achieve mutual separation between the first current channel and the second current channel.

Description

Semiconductor laser device and its manufacturing method and equipment

Technical field

The embodiments of the present application relate to the field of communications, and in particular to a semiconductor laser device and its manufacturing method and equipment.

Background technique

At present, people's demand for information is growing rapidly, and the data rate and data capacity of optical fiber communication systems are increasing sharply. The current mainstream gigabit passive optical network (GPON) is gradually unable to meet the bandwidth requirements of the continuously growing high-bandwidth services. Operators need to consider new technologies to provide higher bandwidth and better services. To enhance the user experience.

It is an inevitable trend for the current mainstream GPON to evolve to a higher rate of 10GPON. The receiving wavelength of GPON is 1310 nanometers (nanometer, nm), the sending wavelength of GPON is 1490 nm, the receiving wavelength of 10GPON is 1270 nm, and the sending wavelength of 10GPON is 1577 nm. In the process of upgrading from GPON to 10G GPON, operators need to consider various requirements, including reusing existing resources, rapid deployment, and forward and backward compatibility. In order to be compatible with the smooth upgrade of the network and reduce construction costs, a combined passive optical network (combo PON) combining GPON and 10G PON has emerged.

Combo optical device is the core device in combo PON, used to realize the conversion of photoelectric signal. The joint optical device needs to include: the transmitter outline (TO) of the two bands of 1490nm and 1577nm, the receiving TO of the two bands of 1310nm and 1270nm, and the corresponding isolator and filter make the structure of the joint optical device very It is complicated and greatly increases the cost of the combined optical device. In order to reduce the cost of United Optical Devices, new technologies are needed to reduce costs.

The two wavelength bands of 1490nm and 1577nm are the most cost-proportioned part of the combined optical device. This requires the production of wide-spaced dual-wavelength lasers on the same chip. The prior art provides a laser structure that uses two sets of independent quantum wells to achieve dual-wavelength lasing. The two lasers provided in the prior art each have a set of quantum wells with different gain peaks, and two sets of quantum wells with different gain peaks. The well is grown epitaxially on the same substrate, and the two lasers share the same set of electrodes.

Although the dual-wavelength laser provided by the above-mentioned prior art can realize dual-wavelength lasing with a relatively wide spacing, the power of the two wavelengths is difficult to balance, and one wavelength will always dominate the lasing process. Since the two wavelength lasers share the same set of electrodes, the two lasers cannot perform signal modulation independently, so the two lasers cannot be optimized independently, which reduces the performance indicators of the lasers.

Summary of the invention

The embodiments of the present application provide a semiconductor laser device and a manufacturing method and equipment thereof, which are used to independently optimize a single laser and improve the performance index of the laser.

In order to solve the above technical problems, the embodiments of this application provide the following technical solutions:

In a first aspect, an embodiment of the present application provides a semiconductor laser device, the semiconductor laser device includes: a first laser and a second laser, wherein the first laser and the second laser are attached to the same substrate layer; The n electrode of the first laser and the n electrode of the second laser are independent of each other, and the p electrode of the first laser and the p electrode of the second laser are independent of each other; When a signal is added to the electrode of the first laser, the current generated in the first laser forms a first current channel. When a second signal is added to the electrode of the second laser, the current generated in the second laser The current forms a second current channel, the modulation of the first laser by the first signal and the modulation of the second laser by the second signal are independent of each other; the second laser includes a cap layer, the The cap layer is used to realize mutual isolation between the first current channel and the second current channel.

In the embodiment of the present application, the semiconductor laser device includes: a first laser and a second laser, wherein the first laser and the second laser are attached to the same substrate layer; the n electrode of the first laser and the n electrode of the second laser are different They are independent of each other, and the p electrode of the first laser and the p electrode of the second laser are independent of each other; when the first signal is added to the electrode of the first laser, the current generated in the first laser forms the first current Channel, when the second signal is added to the electrode of the second laser, the current generated in the second laser forms a second current channel. The modulation of the first laser by the first signal and the modulation of the second laser by the second signal are independent of each other , The second laser includes a cap layer, and the cap layer is used to realize mutual isolation between the first current channel and the second current channel. Since there are two lasers in the semiconductor laser device in the embodiment of the application, the two lasers can form different current channels isolated from each other when adding signals. Each laser can be independently optimized and designed according to its own characteristics. There is no electrical crosstalk between them, so each laser can independently add a modulation signal, which helps to improve the performance of the laser.

In a possible implementation of the first aspect, the first laser includes: a first n-electrode and a first p-electrode; the second laser includes: a second n-electrode and a second p-electrode; the first signal Inject from the first p electrode to the first laser and output from the first n electrode; the second signal is injected from the second p electrode to the second laser and from the second n electrode Electrode output. In practical applications, the current channel isolation between different lasers in the semiconductor laser device can be realized based on the internal hierarchical structure of the second laser. For example, a cap layer is provided in the second laser to realize the first current channel and the second current. The channels are isolated from each other, and the modulation of each signal to the corresponding laser is independent of each other.

In a possible implementation of the first aspect, the first laser further includes: a first epitaxial region, the first n-electrode and the first p-electrode are located at both ends of the first epitaxial region; The second laser further includes: a second epitaxial region, the second n electrode and the second p electrode are located at both ends of the second epitaxial region; the second n electrode, the second p electrode and the The second epitaxial region is located on the same side of the cap layer; the first epitaxial region and the second epitaxial region are isolated from each other by the cap layer, and the first epitaxial region and the second epitaxial region are located Both sides of the cover layer. The epitaxial region in the laser in the embodiments of the present application refers to a hierarchical structure generated by epitaxial growth on the substrate layer. When different epitaxial materials are used for epitaxial growth in the laser, a material layer corresponding to the epitaxial material can be generated. The epitaxial region in the embodiments of the present application refers to a general term for the internal material layers of the laser, and a specific hierarchical structure can be generated when a specific epitaxial material is used for epitaxial growth.

In a possible implementation of the first aspect, the first epitaxial region includes: a first quantum well; the second epitaxial region includes: a second quantum well, the first quantum well and the second quantum well The well is formed by the same epitaxial growth; the first quantum well, the first p electrode, the second n electrode, the second quantum well, the second p electrode and the cap layer are all located Above the substrate layer; the first n electrode is located below the substrate layer; the first p electrode is located above the first quantum well; the cap layer is located between the first quantum well and the Between the second quantum wells; the second n-electrode is located below the second quantum well, and the second p-electrode is located above the second quantum well; the first p-electrode and the first The two n electrodes are separated by the cap layer; the first p electrode and the second p electrode are separated by the cap layer and the second quantum well. In the embodiment of the present application, the first n electrode of the first laser and the second n electrode of the second laser are isolated from each other, the first p electrode of the first laser and the second p electrode of the second laser are isolated from each other, and the first laser of the first laser An n-electrode and the second p-electrode of the second laser are isolated from each other, and the first p-electrode of the first laser and the second n-electrode of the second laser are isolated from each other, so the first current channel in the first laser and the second laser The second current channels are isolated from each other. In the embodiment of this application, when a signal is applied to the electrode of each laser, since each laser can form a current channel belonging to its own laser, each laser can be independently optimized according to its own characteristics By design, there is no electrical crosstalk between the two lasers, so each laser can independently add a modulation signal, which helps to improve the performance of the laser.

In a possible implementation of the first aspect, the first epitaxial region further includes: a first lower separation confinement layer, a first upper separation confinement layer; the second epitaxial region further includes: a second lower separation confinement layer, A second upper separation confinement layer; wherein the first lower separation confinement layer is located between the substrate layer and the first quantum well; the first upper separation confinement layer is located above the first quantum well, And located below the cap layer; the second lower separation confinement layer is located between the cap layer and the second quantum well; the second upper separation confinement layer is located above the second quantum well. In the embodiments of the present application, according to the position distribution of the separation and restriction layers in the laser, they are defined as the upper separation and restriction layers respectively. The separation confinement layer is used to enlarge the optical field distribution of the laser to reduce the optical field intensity of the quantum well region, thereby reducing the thermal effect of the device, and enhancing the confinement effect on electrons, allowing more carriers (electrons and holes) ) Recombination produces photons in the quantum well (ie active region).

In a possible implementation of the first aspect, the first epitaxial region further includes: a first grating layer; the second epitaxial region further includes: a second grating layer; wherein, the first grating layer is formed with A first grating, a second grating is fabricated on the second grating layer; the first grating layer is located above the first upper separation confinement layer; the second grating layer is located on the second upper separation confinement layer Above; the cap layer is located above the first grating layer. In the embodiment of the present application, the first laser includes a grating layer, and the second laser also includes a grating layer. The grating layer is used to make a grating in the laser.

In a possible implementation of the first aspect, the first epitaxial region further includes: a first contact layer, the first contact layer includes: a first ridge waveguide; the second epitaxial region further includes: a second contact The second contact layer includes: a second ridge waveguide; the first contact layer is located between the first grating layer and the first p-electrode; the second contact layer is located on the first Between the second grating layer and the second p electrode. Among them, the contact layer can use p-type indium phosphide (P-InP) material. A ridge waveguide can be etched on the contact layer.

In a possible implementation of the first aspect, the first epitaxial region further includes: a first silicon dioxide layer; the second epitaxial region further includes: a second silicon dioxide layer; A silicon oxide layer is located on the end face of the first ridge waveguide, and the first silicon dioxide layer is located between the first grating layer and the first p electrode; the second silicon dioxide layer is located on the On the end surface of the second ridge waveguide, and the second silicon dioxide layer is located between the second grating layer and the second p electrode. Silicon dioxide is an insulating layer (also called a passivation layer) of the laser, which is mainly used to limit the current injection area.

In a possible implementation of the first aspect, the first ridge waveguide and the second ridge waveguide have the same thickness; the lowest plane where the first ridge waveguide is located is lower than the lowest plane where the second ridge waveguide is located. flat. In the embodiment of the present application, the first contact layer in the first laser and the second contact layer in the second laser are grown and formed at the same time. The first contact layer and the second contact layer are respectively etched by the ridge waveguide to form the second contact layer. A first ridge waveguide of a laser and a second ridge waveguide of a second laser. In order to ensure the epitaxial quality of the two quantum wells, the growth of the two quantum wells is completed within one external delay, but only the first quantum well is used instead of the second quantum well when the first laser works, and the second laser works Only the second quantum well is used instead of the first quantum well. In the embodiment of the present application, in order to fabricate the first laser, part of the hierarchical structure related to the second quantum well is etched away, so that the second ridge waveguide will be higher than the first ridge waveguide, and finally a device shape with uneven heights is formed.

In a possible implementation of the first aspect, the first laser and the second laser are arranged side by side on the substrate layer. In the embodiment of the present application, multiple lasers are arranged side by side on the substrate layer. The side-by-side arrangement is a way of distributing multiple lasers on the substrate layer. Two lasers can be formed side by side on the substrate layer through two epitaxial growth.

In a possible implementation of the first aspect, the second laser is superimposed on the first laser, and the first laser is disposed on the substrate layer. The semiconductor laser device in the embodiment of the application can complete the growth of two quantum wells in one epitaxial growth, and then etch a part of the quantum wells by selective etching, and use different quantum wells to make dual wavelengths with wide wavelength intervals. The laser reduces the number of epitaxy, which is beneficial to improve the performance index and yield of the laser, and reduce the production cost of the laser.

In a second aspect, an embodiment of the present application also provides a multi-wavelength laser, including a semiconductor laser device.

In the second aspect of this application, the component modules of the semiconductor laser device included in the multi-wavelength laser are as described in the foregoing first aspect and various possible implementations. For details, please refer to the foregoing description of the first aspect and various possible implementations. Instructions in the implementation method.

In a third aspect, an embodiment of the present application also provides a semiconductor chip, including a semiconductor laser device.

In the third aspect of the present application, the component modules of the semiconductor laser device included in the semiconductor chip are the structures described in the foregoing first aspect and various possible implementations. For details, please refer to the foregoing first aspect and various possible implementations. Instructions in the method.

In a fourth aspect, an embodiment of the present application further provides an optical module, including: a semiconductor laser device.

In the fourth aspect of the present application, the component modules of the semiconductor laser device included in the optical module are as described in the foregoing first aspect and various possible implementations. For details, refer to the foregoing first aspect and various possible implementations. Instructions in the method.

In a fifth aspect, an embodiment of the present application also provides an optical line terminal (optical line terminal, OLT), including: an optical module.

In the fifth aspect of the present application, the constituent modules of the optical module included in the optical line terminal are as described in the foregoing fourth aspect and various possible implementations. For details, please refer to the foregoing fourth aspect and various possible implementations. Instructions in the method.

In a sixth aspect, an embodiment of the present application also provides an optical network unit (optical network unit, ONU), including an optical module.

In the sixth aspect of the present application, the constituent modules of the optical module included in the optical network unit are as described in the foregoing fourth aspect and various possible implementations. For details, please refer to the foregoing fourth aspect and various possible implementations. Instructions in the method.

In a seventh aspect, an embodiment of the present application also provides a method for manufacturing a semiconductor laser device, including: separately fabricating a first laser and a second laser on the same substrate layer, the second laser including a cap layer, and The layer isolates the first current channel of the first laser and the second current channel of the second laser from each other; configures independent n electrodes for the first laser and the second laser, and provides The first laser and the second laser are configured with mutually independent p-electrodes.

The semiconductor laser device can be generated by the manufacturing method provided by the embodiment of the application. Two lasers are provided in the semiconductor laser device. The two lasers can form different current channels isolated from each other when adding signals. Each laser can be based on its own characteristics. Independent optimization design, there is no electrical crosstalk between the two lasers, so each laser can independently add modulation signals, so it helps to improve the performance of the laser.

In a possible implementation of the seventh aspect, the separately fabricating the first laser and the second laser on the same substrate layer includes: performing a first epitaxy on the front surface of the substrate layer and passing the first laser A first epitaxial structure is grown by sub-epitaxial growth. The first epitaxial structure includes the following hierarchical structures from bottom to top: a first epitaxial region, the cap layer, and a second epitaxial region, wherein the first epitaxial region belongs to the The first laser, the second epitaxial region belongs to the second laser; the left and right sides of the first epitaxial structure are selectively etched to obtain the second epitaxial structure; the right side of the second epitaxial structure Etching on the surface to obtain a third epitaxial structure, the cap layer on the right side of the third epitaxial structure is etched away, and the cap layer remains on the left side of the third epitaxial structure . In the embodiment of the present application, a variety of epitaxial materials can be used during the first epitaxial delay, and a first epitaxial structure is grown through the first epitaxial growth. The first epitaxial structure includes the following hierarchical structure from bottom to top: Zone, cap layer, second epitaxial zone. Among them, the first epitaxial region belongs to the first laser, and the second epitaxial region belongs to the second laser. The cap layer functions to isolate the first laser from the second laser, and the cap layer also functions as a substrate for the second laser. . After the first epitaxial structure is obtained, the left and right sides of the first epitaxial structure are selectively etched. For example, the left and right ends of the second epitaxial region in the first epitaxial structure can be etched away, and then the second epitaxial structure can be obtained. structure. Next, a second selected area etching is performed to etch away the cap layer on the right side of the second epitaxial structure. At this time, the third epitaxial structure can be obtained. The third epitaxial structure has two end surfaces: a right side and a left side. The cap layer on the right side of the third epitaxial structure is etched away, and the cap layer remains on the left side of the third epitaxial structure.

In a possible implementation of the seventh aspect, the first laser and the second laser are configured with mutually independent n electrodes, and the first laser and the second laser are configured with mutually independent p The electrode includes: fabricating a first p-electrode above the first epitaxial region; fabricating a second p-electrode above the second epitaxial region; and a cap layer on the left side of the third epitaxial structure A second n-electrode is fabricated on the upper surface, wherein the second n-electrode and the second p-electrode belong to the second laser; the backside of the substrate layer is thinned and fabricated on the backside of the substrate layer A first n electrode, wherein the first n electrode and the first p electrode belong to the first laser. In the embodiment of the present application, the first n electrode of the first laser and the second n electrode of the second laser are isolated from each other, the first p electrode of the first laser and the second p electrode of the second laser are isolated from each other, and the first laser of the first laser An n-electrode and the second p-electrode of the second laser are isolated from each other, and the first p-electrode of the first laser and the second n-electrode of the second laser are isolated from each other, so the first current channel in the first laser and the second laser The second current channels are isolated from each other. In the embodiment of this application, when a signal is applied to the electrode of each laser, since each laser can form a current channel belonging to its own laser, each laser can be independently optimized according to its own characteristics By design, there is no electrical crosstalk between the two lasers, so each laser can independently add a modulation signal, which helps to improve the performance of the laser.

In a possible implementation of the seventh aspect, the performing the first epitaxy on the front surface of the substrate layer, and growing the first epitaxial structure through the first epitaxy, further includes: The first epitaxial growth is performed on the front side, and the first lower separation confinement layer, the first quantum well, the first upper separation confinement layer, the first grating layer, the cap layer, the second lower separation confinement layer, and the second A quantum well, a second upper separation confinement layer, and a second grating layer; wherein the first lower separation confinement layer, the first quantum well, the first upper separation confinement layer and the first grating layer all belong to The first epitaxial region; the second lower separation confinement layer, the second quantum well, the second upper separation confinement layer, and the second grating layer all belong to the second epitaxial region. In the embodiment of the present application, the upper and lower layers of the first quantum well use separation confinement layers, and the upper and lower layers of the second quantum well use separation confinement layers, which are defined as upper layers according to the position distribution of the separation and confinement layers in the laser. The separation restriction layer and the lower separation restriction layer.

In a possible implementation of the seventh aspect, the method further includes: after the first grating layer is grown on the first upper separation confinement layer, fabricating a first grating layer on the first grating layer Grating, the first grating belongs to the first laser; after the second grating layer is grown on the second upper separation limiting layer, a second grating is fabricated on the second grating layer, the The second grating belongs to the second laser.

In a possible implementation of the seventh aspect, after the selective etching is performed on the right side of the second epitaxial structure to obtain the third epitaxial structure, the method further includes: A protective layer is grown on the cap layer on the left side. Wherein, the composition of the protective layer may be silicon dioxide, and the main function of this protective layer is to ensure that the part used to make the second n-electrode is not grown on the P-InP layer during the secondary epitaxy process.

In a possible implementation of the seventh aspect, after the growth of a protective layer on the cap layer on the left side of the third epitaxial structure, the method further includes: on the first grating layer, the A second epitaxy is performed on the second grating layer, a first contact layer is grown on the first grating layer through the second epitaxy, and a second contact layer is grown on the second grating layer; A first ridge waveguide is etched from the first contact layer, and a second ridge waveguide is etched from the second contact layer, the first ridge waveguide belongs to the first epitaxial region, and the second ridge waveguide The two-ridge waveguide belongs to the second epitaxial region; wherein, the first contact layer is located between the first grating layer and the first p electrode; the second contact layer is located in the second grating Between the layer and the second p-electrode. In the embodiment of this application, only two epitaxial growth are required. Through the second epitaxy, the first contact layer and the second contact layer can be grown. The contact layer can use P-InP material, and the ridge waveguide can be etched on the contact layer. .

In a possible implementation of the seventh aspect, after the first ridge waveguide is etched from the first contact layer and the second ridge waveguide is etched from the second contact layer, the method It also includes: growing a first silicon dioxide layer on the first grating layer and the first ridge waveguide, and growing a second silicon dioxide layer on the second grating layer and the second ridge waveguide Layer; wherein, the first silicon dioxide layer belongs to the first epitaxial region, and the second silicon dioxide layer belongs to the second epitaxial region. In the embodiments of the present application, the first laser includes a silicon dioxide layer, and the second laser also includes a silicon dioxide layer. Silicon dioxide is an insulating layer (also called a passivation layer) of the laser, which is mainly used to limit the current injection area.

In a possible implementation of the seventh aspect, the first silicon dioxide layer is grown on the first grating layer and the first ridge waveguide, and the second grating layer and the second After the second silicon dioxide layer is grown on the ridge waveguide, the method further includes: cleaning the protective layer from the cover layer on the left side of the third epitaxial structure; and removing the first ridge waveguide The first silicon dioxide layer on the top of the second ridge waveguide is etched away, and the second silicon dioxide layer on the top of the second ridge waveguide is etched away. In the embodiment of this application, only the top of the first ridge waveguide, the top of the second ridge waveguide, and the bottom of the second n-electrode are not covered by silicon dioxide. In this way, the distribution of silicon dioxide ensures that the current injected into the second ridge waveguide can only flow from the first ridge waveguide. Two n-electrodes flow out, and the current injected from the first ridge waveguide can only flow out from the first n-electrode. Therefore, the first laser and the second laser can have mutually isolated current channels, so that the two lasers can independently add modulation signals.

In a possible implementation of the seventh aspect, the first p-electrode is located above the first silicon dioxide layer and above the top of the first ridge waveguide; and the second p-electrode is located above the first ridge waveguide. Above the second silicon dioxide layer and above the top of the second ridge waveguide. Among them, after the silicon dioxide layer is windowed, the silicon dioxide on the top of the two ridge waveguides can be etched away, and the P electrode can be added to the top of the silicon dioxide layer, so that the P electrode can establish the hierarchical structure inside the laser The current channel.

Description of the drawings

1 is a schematic diagram of a structure of a semiconductor laser device provided by an embodiment of the application;

2 is a schematic diagram of another composition structure of a semiconductor laser device provided by an embodiment of the application;

3 is a schematic diagram of another composition structure of a semiconductor laser device provided by an embodiment of the application;

4 is a schematic block diagram of a process flow of a method for manufacturing a semiconductor laser device according to an embodiment of the application;

FIG. 5a is a schematic diagram of a structure in a manufacturing process of a dual-wavelength laser provided by an embodiment of the application;

5b is another schematic diagram of the structure in the manufacturing process of the dual-wavelength laser provided by the embodiment of the application;

5c is another schematic diagram of the structure in the manufacturing process of the dual-wavelength laser provided by the embodiment of the application;

5d is another schematic diagram of the structure in the manufacturing process of the dual-wavelength laser provided by the embodiment of the application;

5e is another schematic diagram of the structure in the manufacturing process of the dual-wavelength laser provided by the embodiment of the application;

5f is another schematic diagram of the structure in the manufacturing process of the dual-wavelength laser provided by the embodiment of the application;

FIG. 5g is a schematic diagram of another structure in the manufacturing process of a dual-wavelength laser provided by an embodiment of the application.

detailed description

The embodiments of the present application will be described below in conjunction with the drawings.

The terms "first" and "second" in the description and claims of the application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific sequence or sequence. It should be understood that the terms used in this way can be interchanged under appropriate circumstances, and this is merely a way of distinguishing objects with the same attributes in the description of the embodiments of the present application. In addition, the terms "including" and "having" and any variations of them are intended to cover non-exclusive inclusion, so that a process, method, system, product, or device containing a series of units is not necessarily limited to those units, but may include Listed or inherent to these processes, methods, products or equipment.

The embodiments of the present application provide a semiconductor laser device that can be used to generate signals of at least two different wavelengths, depending on the number of lasers included in the semiconductor laser device.

The embodiments of the present application also provide a multi-wavelength laser, which may include the aforementioned semiconductor laser device. The multi-wavelength laser can be used to produce wide-spaced multi-wavelength signals on the same chip. For example, the multi-wavelength laser may include a dual-wavelength laser, such as a dual-wavelength laser of 1490 nm and 1577 nm.

The embodiments of the present application also provide a semiconductor chip, which may include the aforementioned semiconductor laser device.

The embodiment of the present application also provides an optical module including: a semiconductor laser device.

An embodiment of the present application also provides an optical line terminal, including: the foregoing optical module.

An embodiment of the present application also provides an optical network unit, including: the foregoing optical module.

Both the optical line terminal and the optical network unit provided in the embodiments of this application can be components of a passive optical network (PON) system. The optical line terminal is used to connect to the network backbone, and the optical network unit is used to connect to a local area network or a home. user.

Next, an example of a semiconductor laser device provided in an embodiment of the present application will be described. As shown in FIG. 1, the semiconductor laser device 100 provided by the embodiment of the present application includes: a first laser 101 and a second laser 102, wherein,

The first laser 101 and the second laser 102 are attached to the same substrate layer 103;

The n electrodes of the first laser 101 and the n electrodes of the second laser 102 are independent of each other, and the p electrodes of the first laser 101 and the p electrodes of the second laser 102 are independent of each other;

When the first signal is added to the electrode of the first laser 101, the current generated in the first laser 101 forms the first current channel, and when the second signal is added to the electrode of the second laser 102, the current generated in the second laser 102 forms the first Two current channels, the modulation of the first laser 101 by the first signal and the modulation of the second laser 102 by the second signal are independent of each other;

The second laser 102 includes a cap layer 104, and the cap layer 104 is used to achieve mutual isolation between the first current channel and the second current channel.

In the embodiment of the present application, the number of lasers included in the semiconductor laser device may be two or more. In FIG. 1, the semiconductor laser device includes two lasers for illustration. When the semiconductor laser device includes three lasers, the structural characteristics between the two lasers still meet the constraints of the composition structure and connection relationship of the two lasers shown in FIG. 1 above. In the subsequent embodiments, the semiconductor laser device includes The two lasers are illustrated as examples, but they are not used as a limitation on the composition structure of the semiconductor laser device provided in the embodiment of the present application.

In the embodiment of the present application, the substrate layer may be an n-type indium phosphide (n-InP) material, and multiple lasers in the semiconductor laser device may be shared and attached to the same substrate layer.

In the embodiments of the present application, each laser included in the semiconductor laser device is separately provided with an electrode belonging to the respective laser, that is, electrodes are no longer shared between different lasers. Specifically, the n electrodes of the first laser and the n electrodes of the second laser are independent of each other, that is, each laser has an n electrode dedicated to the laser, and the n electrodes are not shared among multiple lasers. Similarly, the p-electrodes of the first laser 101 and the p-electrodes of the second laser are independent of each other, that is, each laser has a p-electrode dedicated to the laser, and the p-electrodes are not shared among multiple lasers. In the embodiment of the present application, multiple lasers in the semiconductor laser device are commonly attached to the same substrate layer, but each laser can form a current channel belonging to its own laser. Among them, the current channel means that when a signal is applied to the electrodes of the laser, the current generated on the laser forms a charge movement inside the laser, and the charge movement inside the laser forms a current channel.

In the embodiment of the present application, the first signal can be used to modulate the first laser, and the second signal can be used to modulate the second laser. The first signal and the second signal are electrical signals that need to be added to the laser Only electrodes can modulate the laser. Among them, the first signal can be added to the electrode of the first laser, and the second signal can be added to the electrode of the second laser. For example, when the same substrate layer to which the first laser and the second laser are attached is an n-type substrate, the first signal can be injected from the p electrode of the first laser, and the second signal can be injected from the p electrode of the second laser. For example, when the same substrate layer to which the first laser and the second laser are attached is a p-type substrate, the first signal can be injected from the n electrode of the first laser, and the second signal can be injected from the n electrode of the second laser. The injection method of the electrical signal in the laser is used as an example here, and is not a limitation of the application.

In the embodiments of the present application, the current channels of each laser are isolated from each other by the cover layer, wherein the current channels of different lasers are isolated from each other means that the charge movement in different current channels will not be affected by the charge movement in other lasers. In the embodiment of the present application, when a signal is applied to the electrode of each laser, since each laser can form a current channel belonging to its own laser, each laser can be independently optimized and designed according to its own characteristics. There is no electrical crosstalk between the first laser and the second laser, or the electrical crosstalk between the first laser and the second laser is small, and will not affect the performance indicators of the respective lasers, so that each laser can independently add a modulation signal, Therefore, it helps to improve the performance index of the laser.

In some embodiments of the present application, each laser may have n-electrodes and p-electrodes. For example, as shown in FIG. 1, the first laser 101 includes: a first n-electrode 1011 and a first p-electrode 1012; and the second laser 102 includes: The second n electrode 1021 and the second p electrode 1022;

The first signal is injected from the first p-electrode 1012 into the first laser 101 and output from the first n-electrode 1011;

The second signal is injected into the second laser 102 from the second p-electrode 1022 and output from the second n-electrode 1021.

The broad arrow in Fig. 1 represents the current channel generated when a signal is applied to the laser. The current channel is a schematic illustration here to illustrate that the first current channel and the second current channel are isolated from each other. In practical applications, the current channel isolation between different lasers in the semiconductor laser device can be implemented based on the internal hierarchical structure of the second laser. For example, a cap layer 104 is provided in the second laser, and the cap layer 104 is used to realize the first current channel. Mutual isolation between and the second current channel.

In the embodiment of the present application, the cap layer 104 may be used to isolate the first current channel and the second current channel from each other. Wherein, the cap layer 104 may use n-type doped materials to ensure that the second laser 102 can form a complete PIN structure. The cap layer 104 can also be used as a supporting layer for the second n-electrode 1021 of the second laser 102. Through the cap layer 104, the second laser 102 can form a second current channel independent of the first current channel, such as a second current channel. The channel may include: a current generated by the second signal is injected from the second p-electrode 1022 into the second laser 102, and then after passing through the cap layer 104, the current flows out of the second n-electrode 1021 to form a current channel.

In some embodiments of the present application, the cap layer 104 includes: an n-type indium phosphide (n-InP) layer and an intrinsic indium phosphide (Intrinsic-InP, referred to as I-InP) layer, and intrinsic means no doping . Among them, the n-InP layer can be used to form the PIN junction of the second laser. Below the n-InP layer is the intrinsic InP layer (also referred to as the I-InP layer for short). The intrinsic InP layer has a larger resistance value. This effectively prevents the current from the second p-electrode 1022 from flowing to the first laser 101.

The laser structure provided by the embodiment of the application is a PIN junction. Wherein, P refers to a P-type doped (such as P-InP) layer, I refers to an intrinsic indium phosphide layer, and n is an n-type doped (such as n-InP) layer. Wherein, the resistance of the n-type doped layer<the resistance of the p-type doped layer<the resistance of the intrinsic indium phosphide layer. The second laser may include a cap layer, the cap layer may include an n-InP layer and an I-InP layer, the n-InP layer functions as an n-type doped layer required by the second laser, and the I-InP layer functions as a prevention layer The effect of the two lasers injecting current into the first laser.

In some embodiments of the present application, each laser may include: n-pole and p-pole, and the n-electrodes of all lasers in the semiconductor laser device are mutually independent, and the p-electrodes of all lasers are mutually independent. Independent, for example, the first laser 101 includes: a first n electrode 1011 and a first p electrode 1012, the second laser 102 includes: a second n electrode 1021 and a second p electrode 1022, a first n electrode 1011 and a second n electrode 1021 are two completely different n-electrodes. Similarly, the first p-electrode 1012 and the second p-electrode 1022 are two completely different p-electrodes.

It should be noted that when the number of lasers in the semiconductor laser device is three, three different n-electrodes and three different p-electrodes need to be provided in the semiconductor laser device. The case where the semiconductor laser device includes 4 lasers is similar to the case of 3 lasers, and will not be illustrated one by one here.

Based on the first current channel and the second current channel shown in FIG. 1, the first signal is injected from the first p-electrode 1012 into the first laser 101 and output from the first n-electrode 1011, and the second signal is from the second p-electrode 1022 It is injected into the second laser 102 and output from the second n electrode 1021. Therefore, in the embodiments of the present application, the signal modulation of the first laser is not related to the second laser, so independent signal modulation of the first laser can be performed. In the same way, in the embodiments of the present application, independent signal modulation may be performed on the second laser. If the number of lasers in the semiconductor laser device is three, the embodiment of the present application can also perform independent signal modulation on the three lasers. Therefore, the three lasers can be independently optimized and designed according to their own characteristics, which is helpful to improve the laser performance. Performance.

In some embodiments of the present application, please refer to FIG. 2. The first laser provided by the embodiments of the present application further includes: a first epitaxial region 1013, and the first n electrode 1011 and the first p electrode 1012 are located in the first epitaxial region Both ends of 1013;

The second laser further includes: a second epitaxial region 1023, the second n electrode 1021 and the second p electrode 1022 are located at both ends of the second epitaxial region 1023; the second n electrode 1021, the second p electrode 1022 and the second epitaxial region 1023 Located on the same side of the cap layer 104;

The first epitaxial region 1013 and the second epitaxial region 1023 are separated from each other by the cap layer 104, and the first epitaxial region 1013 and the second epitaxial region 1023 are located on both sides of the cap layer 104.

Among them, the epitaxial region in the laser refers to the hierarchical structure generated by epitaxial growth on the substrate layer, and the material layer corresponding to the epitaxial material can be generated when different epitaxial materials are used for epitaxial growth in the laser. For example, when the epitaxial material is a semiconductor material, the generated epitaxial region may include: multiple quantum well structure (MQWs), which may also be referred to as quantum well for short. The epitaxial region in the embodiments of the present application refers to the general term of the internal material layers of the laser, and a specific hierarchical structure can be generated when a specific epitaxial material is used for epitaxial growth. For details, please refer to the example of the laser manufacturing method in the subsequent embodiments.

As shown in FIG. 2, the second laser includes a cap layer 104. The first epitaxial region 1013 and the second epitaxial region 1023 are isolated from each other by the cap layer 104, and the first epitaxial region 1013 and the second epitaxial region 1023 are located on two sides of the cap layer 104. On the other hand, for example, in FIG. 2, the first epitaxial region 1013 is located below the cap layer 104, and the second epitaxial region 1023 is located above the cap layer 104, so that the first laser and the second laser can respectively form mutually isolated current channels. In addition, the cap layer 104 can provide the function of an n-type doped layer for the second laser. The second n electrode 1021, the second p electrode 1022 and the second epitaxial region 1023 are located on the same side of the cap layer 104, so the second laser The current channel of is isolated above the cap layer 104, so that the second laser can form a separate current channel.

In some embodiments of the present application, as shown in FIG. 3, a schematic diagram of another composition structure of the semiconductor laser device provided in the embodiments of the present application. The first laser includes a first quantum well 4 (for example, MQWs1 shown in 3), for example, the first epitaxial region includes: the first quantum well 4. The second laser includes a second quantum well 11 (for example, MQWs2 shown in FIG. 3). For example, the second epitaxial region includes a second quantum well. When the semiconductor laser device is fabricated, the first epitaxial generation can be performed on the substrate layer. Two quantum wells are formed at the same time.

Further, the first quantum well 4 and the second quantum well 11 use different semiconductor materials. For example, the first quantum well uses Al _0.105 Ga _0.195 In _0.7 As material, and the second quantum well uses Al _0.161 Ga _0.102 In _0.737 As material, and the two quantum wells have different material compositions. Therefore, the first quantum well 4 and the second quantum well 11 have different lasing wavelengths. For example, the lasing wavelength of the first quantum well 4 is near 1577 nm, and the lasing wavelength of the second quantum well 11 is near 1490 nm.

As shown in FIG. 3, the first quantum well 4, the first p-electrode 7, the second n-electrode 9, the second quantum well 11, the second p-electrode 14 and the cap layer are all located in the substrate layer 2 (for example, as shown in FIG. n-InP1) above;

The first n electrode 1 is located under the substrate layer 2;

The first p electrode 7 is located above the first quantum well 4;

The cap layer is located between the first quantum well 4 and the second quantum well 11;

The second n electrode 9 is located below the second quantum well 11, and the second p electrode 14 is located above the second quantum well 11;

The first p-electrode 7 and the second n-electrode 9 are separated by a cap layer;

The first p-electrode 7 and the second p-electrode 14 are separated by a cap layer and the second quantum well 11.

Among them, as shown in FIG. 3, the cover layer includes: n-InP layer 8a and I-InP layer 8b, n-InP layer 8a is used to form the PIN structure of second laser 102, and I-InP layer 8b is used to enhance electrical isolation . In Figure 3, the first n-electrode 1 is located below the substrate layer 2, the first p-electrode 7 and the second n-electrode 9 are separated by a cap layer, and the first p-electrode 7 and the second p-electrode 14 pass through the cap layer and the second quantum The well 11 is isolated, so the first n-electrode of the first laser and the second n-electrode of the second laser are isolated from each other, and the first p-electrode of the first laser and the second p-electrode of the second laser are isolated from each other. The first n electrode and the second p electrode of the second laser are isolated from each other, and the first p electrode of the first laser and the second n electrode of the second laser are isolated from each other, so the first current channel and the second laser in the first laser The second current channels are isolated from each other. In the embodiment of the present application, when a signal is applied to the electrode of each laser, since each laser can form a current channel belonging to its own laser, each laser can be independent according to its own characteristics. Optimized design, there is no electrical crosstalk between the two lasers, so each laser can add modulation signals independently, which helps to improve the performance of the laser.

Further, in some embodiments of the present application, the first laser includes a separate confinement heterostructure (SCH), and the second laser also includes a separate confinement layer. Specifically, the upper and lower layers of the first quantum well in the first laser use separation confinement layers, and the upper and lower layers of the second quantum well in the second laser respectively use separation confinement layers. As shown in FIG. 3, the first epitaxial region further includes: a first lower separation confinement layer 3, a first upper separation confinement layer 5; the second epitaxial region further includes: a second lower separation confinement layer 10, a second upper separation confinement layer 12; among them,

The first lower separation confinement layer 3 is located between the substrate layer 1 and the first quantum well 4;

The first upper separation confinement layer 5 is located above the first quantum well 4 and below the cap layer;

The second lower separation confinement layer 10 is located between the cap layer and the second quantum well 11;

The second upper separation confinement layer 12 is located above the second quantum well 11.

Among them, in FIG. 3, the upper and lower layers adjacent to the first quantum well 4 are separation confinement layers, and the upper and lower layers adjacent to the second quantum well 11 are separation confinement layers. According to the position of the separation confinement layer in the laser Different distributions are defined as upper separation restriction layer and lower separation restriction layer. The separation confinement layer is used to enlarge the optical field distribution of the laser to reduce the optical field intensity of the quantum well region, thereby reducing the thermal effect of the device, and enhancing the confinement effect on electrons, allowing more carriers (electrons and holes) ) Recombination produces photons in the quantum well (ie active region).

Further, in some embodiments of the present application, the first laser includes a grating layer, and the second laser also includes a grating layer. The grating layer is used to produce a grating in the laser, and the production process and process of the grating are not described in detail in the embodiment of the present application.

As shown in FIG. 3, the first epitaxial region further includes: a first grating layer 6 (for example, the grating layer 1 in FIG. 3); the second epitaxial region also includes: a second grating layer 13 (for example, the grating layer 2 in FIG. 3). );among them,

A first grating is made on the first grating layer 6 and a second grating is made on the second grating layer 13;

The first grating layer 6 is located above the first upper separation limiting layer 5;

The second grating layer 13 is located above the second upper separation limiting layer 12;

The cover layer is located above the first grating layer 6.

Among them, as shown in FIG. 3, the cover layer includes: n-InP layer 8a and I-InP layer 8b, n-InP layer 8a is used to form the PIN structure of second laser 102, and I-InP layer 8b is used to enhance electrical isolation . A first grating is fabricated on the first grating layer 6 shown in FIG. 3, and a second grating is fabricated on the second grating layer 13. The first grating and the second grating are not shown in FIG. 3, which are only described here. Not as a limitation to the embodiments of the present application.

Further, in some embodiments of the present application, the first laser includes a contact layer, and the second laser also includes a contact layer. Among them, the contact layer can use p-type indium phosphide (P-InP) material. A ridge waveguide can be etched on the contact layer. As shown in FIG. 3, the first epitaxial region further includes: a first contact layer, the first contact layer includes: a first ridge waveguide 16a; the second epitaxial region further includes: a second contact layer, the second contact layer includes: a second Ridge waveguide 16b;

The first contact layer is located between the first grating layer 6 and the first p electrode 7;

The second contact layer is located between the second grating layer 13 and the second p electrode 14.

Wherein, the contact layer in FIG. 3 can use P-InP material, and the ridge waveguide can be etched on the contact layer. The manufacturing process and process of the ridge waveguide in the embodiment of the present application will not be described in detail. The ridge waveguide is used to limit the injection channel of the laser current and constrain the mode of the laser to ensure that the laser performs single-mode lasing.

Further, in some embodiments of the present application, the first laser includes a silicon dioxide layer, and the second laser also includes a silicon dioxide layer. Silicon dioxide is an insulating layer (also called a passivation layer) of the laser, which is mainly used to limit the current injection area. As shown in FIG. 3, the first epitaxial region further includes: a first silicon dioxide layer 15a; the second epitaxial region further includes: a second silicon dioxide layer 15b; wherein,

The first silicon dioxide layer 15a is located on the end surface of the first ridge waveguide 16a, and the first silicon dioxide layer 15a is located between the first grating layer 6 and the first p electrode 7;

The second silicon dioxide layer 15b is located on the end surface of the second ridge waveguide 16b, and the second silicon dioxide layer 15b is located between the second grating layer 13 and the second p-electrode 14.

Among them, the silicon dioxide on the top of the first ridge waveguide 16a and the second ridge waveguide 16b shown in FIG. 3 is etched away, so that the first p electrode 7 can be fabricated on the top of the first ridge waveguide 16a, and the second ridge waveguide A second p-electrode 14 is formed on the top of 16b. In FIG. 3, only the top of the first ridge waveguide 16a, the top of the second ridge waveguide 16b, and the bottom of the second n-electrode 9 are not covered by silicon dioxide. Based on the above-mentioned silicon dioxide distribution, it can be guaranteed that the second ridge waveguide 16b The injected current can only flow from the second n-electrode 9, and the current injected from the first ridge waveguide 16a can only flow from the first n-electrode 1. The first laser and the second laser can have mutually isolated current channels, so that the two Each laser can add modulation signals independently.

In some embodiments of the present application, the first ridge waveguide 16a and the second ridge waveguide 16b have the same thickness;

The lowest plane where the first ridge waveguide 16a is located is lower than the lowest plane where the second ridge waveguide 16b is located.

Among them, as shown in Figure 3, the first contact layer in the first laser and the second contact layer in the second laser are grown at the same time, and ridge waveguide etching is performed on the first contact layer and the second contact layer respectively. Thereby, the first ridge waveguide of the first laser and the second ridge waveguide of the second laser are formed. In addition, the first ridge waveguide and the ridge waveguide can have the same ridge waveguide width or different ridge waveguide widths, as long as the two ridge waveguides can ensure the transverse mode lasing of the laser, and there is no strict limit on the ridge waveguide width. .

In some embodiments of the present application, when the first ridge waveguide 16a and the second ridge waveguide 16b have the same thickness, the two ridge waveguides are arranged in a staggered arrangement, and the lowest plane of each ridge waveguide is measured. The lowest plane where 16a is located is lower than the lowest plane where the second ridge waveguide 16b is located. In order to ensure the epitaxial quality of the two quantum wells, the growth of the two quantum wells is completed within one external delay, but only the first quantum well is used instead of the second quantum well when the first laser works, and the second laser works Only the second quantum well is used instead of the first quantum well. In the embodiment of the present application, in order to fabricate the first laser, part of the hierarchical structure related to the second quantum well is etched away, so that the second ridge waveguide will be higher than the first ridge waveguide, and finally a device shape with uneven heights is formed.

In some embodiments of the present application, the first laser and the second laser are arranged side by side on the substrate layer.

Among them, the semiconductor laser device provided in the embodiment of the present application is provided with at least two lasers, and these lasers are all attached to the same substrate layer, and multiple lasers are arranged side by side on the substrate layer. The side-by-side arrangement is a way of distributing multiple lasers on the substrate layer. Two lasers can be formed side by side on the substrate layer through two epitaxial growth.

In some embodiments of the present application, as shown in FIG. 1 or FIG. 2, the second laser 102 is superimposed on the first laser 101, and the first laser 101 is disposed on the substrate layer 103.

In the semiconductor laser device shown in FIG. 3, two lasers are arranged in a stacked manner. Among them, there are two quantum wells (i.e. active regions) under the ridge waveguide of the second laser 102, and there is only one quantum well (i.e. active regions) under the ridge waveguide of the first laser 101. The two lasers are not only attached to the same substrate. Except for the bottom layer, the two lasers do not share another epitaxial region structure, and the four electrodes of the two lasers are completely separated. This structural feature allows the semiconductor laser device to complete the growth of two quantum wells in one epitaxial growth, and then etch a part of the quantum wells through selective etching, and use different quantum wells to make dual wavelengths with wide wavelength intervals. The laser reduces the number of epitaxy, which is beneficial to improve the performance index and yield of the laser, and reduce the production cost of the laser.

The foregoing embodiment describes the semiconductor laser device provided in the present application. Next, the manufacturing method of the semiconductor laser device is described. As shown in FIG. 4, the manufacturing method of the semiconductor laser device provided in the embodiment of the present application includes the following steps:

401. The first laser and the second laser are respectively fabricated on the same substrate layer, the second laser includes a cap layer, and the first current channel of the first laser and the second current channel of the second laser are isolated from each other by the cap layer.

In the embodiment of the present application, the substrate layer can be made of n-InP material, and multiple lasers in the semiconductor laser device can be shared and attached to the same substrate layer.

In the embodiment of the present application, multiple lasers can be fabricated on the same substrate layer. For example, when three lasers are included in a semiconductor laser device, the structural characteristics between the two lasers still meet the two requirements shown in Figure 1 above. The composition structure of the laser and the restriction of the connection relationship are described in the following embodiments by taking two lasers included in the semiconductor laser device as an example, but it is not used as a limitation on the composition structure of the semiconductor laser device provided in the embodiments of the present application.

In the embodiment of the present application, a cap layer is provided between the first laser and the second laser, and the first current channel of the first laser and the second current channel of the second laser are isolated from each other by the cap layer. When each laser in the semiconductor laser device does not share an electrode, although multiple lasers in the semiconductor laser device are attached to the same substrate layer, each laser can form a current channel belonging to its own laser. Among them, the current channel means that when a signal is applied to the electrode of the laser, the current generated on the laser forms a charge movement inside the laser, and the charge movement in the laser forms a current channel. The isolation of the current channels of each laser means that the charge movement in different current channels will not be affected by the charge movement in other lasers. In the embodiment of the application, when a signal is applied to the electrode of each laser, since each laser can form a current channel belonging to its own laser, each laser can be independently optimized according to its own characteristics, and there is no electrical crosstalk between the two lasers. , Or the electrical crosstalk between the two lasers is very small and does not affect the performance indicators of the respective lasers. Therefore, each laser can independently add modulation signals, thus helping to improve the performance indicators of the laser.

In some embodiments of the present application, step 401 separately fabricating the first laser and the second laser on the same substrate layer includes:

A1. Perform the first epitaxy on the front surface of the substrate layer, and grow the first epitaxial structure through the first epitaxial growth. The first epitaxial structure includes the following hierarchical structures from bottom to top: first epitaxial region, cap layer, second epitaxial region Zone, where the first epitaxial zone belongs to the first laser, and the second epitaxial zone belongs to the second laser;

A2. Perform selective etching on the left and right sides of the first epitaxial structure to obtain the second epitaxial structure;

A3. Perform selective etching on the right side of the second epitaxial structure to obtain a third epitaxial structure. The cap layer on the right side of the third epitaxial structure is etched away, and the left side of the third epitaxial structure remains Cap layer.

Among them, the substrate layer is provided first, and then the first epitaxy is performed on the front surface of the substrate layer. In the first epitaxy, a variety of epitaxial materials can be used, and the first epitaxial structure is grown through the first epitaxy. The structure includes the following hierarchical structure from bottom to top: the first epitaxial region, the cap layer, and the second epitaxial region. Among them, the first epitaxial region belongs to the first laser, and the second epitaxial region belongs to the second laser. The cap layer functions to isolate the first laser from the second laser, and the cap layer also functions as a substrate for the second laser. .

After the first epitaxial structure is obtained, the left and right sides of the first epitaxial structure are selectively etched. For example, the left and right ends of the second epitaxial region in the first epitaxial structure can be etched away, and then the second epitaxial structure can be obtained. structure. Next, a second selected area etching is performed to etch away the cap layer on the right side of the second epitaxial structure. At this time, the third epitaxial structure can be obtained. The third epitaxial structure has two end surfaces: a right side and a left side. The cap layer on the right side of the third epitaxial structure is etched away, and the cap layer remains on the left side of the third epitaxial structure.

402. Configure mutually independent n electrodes for the first laser and the second laser, and configure mutually independent p electrodes for the first laser and the second laser.

In the embodiment of the present application, the first laser and the second laser are separately provided with electrodes belonging to the respective lasers, that is, electrodes are no longer shared between different lasers.

Further, in some embodiments of the present application, in the foregoing implementation scenario of performing step A1 to step A3, step 402 is to configure independent n electrodes for the first laser and the second laser, and for the first laser and the second laser. The laser is configured with independent p-electrodes, including:

B1. Fabricating a first p electrode above the first epitaxial region;

B2. Fabricate a second p-electrode above the second epitaxial region;

B3. Fabricate a second n electrode on the cover layer on the left side of the third epitaxial structure, where the second n electrode and the second p electrode belong to the second laser;

B4. Thin the back surface of the substrate layer, and fabricate a first n electrode on the back surface of the substrate layer, where the first n electrode and the first p electrode belong to the first laser.

As shown in FIG. 3, the first n-electrode 1 is located below the substrate layer 2, the first p-electrode 7 and the second n-electrode 9 are separated by a cap layer, and the first p-electrode 7 and the second p-electrode 14 pass through the cap layer, The second quantum well 11 is isolated, so the first n electrode of the first laser and the second n electrode of the second laser are isolated from each other, and the first p electrode of the first laser and the second p electrode of the second laser are isolated from each other. The first n electrode of a laser and the second p electrode of the second laser are isolated from each other, and the first p electrode of the first laser and the second n electrode of the second laser are isolated from each other, so the first current channel in the first laser is The second current channels in the second laser are isolated from each other. In the embodiment of this application, when a signal is applied to the electrode of each laser, since each laser can form a current channel belonging to its own laser, each laser can be based on its own characteristics. Independent optimization design, there is no electrical crosstalk between the two lasers, so each laser can independently add modulation signals, so it helps to improve the performance of the laser.

In some embodiments of the present application, step 401 performs the first epitaxy on the front surface of the substrate layer, and the first epitaxial structure is grown by the first epitaxy. In addition to the aforementioned steps A1 to A3, step 401 can also include:

A4. Perform the first epitaxial growth on the front surface of the substrate layer, and grow the first lower separation confinement layer, the first quantum well, the first upper separation confinement layer, the first grating layer, the cap layer, and the second lower separation confinement layer. Layer, second quantum well, second upper separation confinement layer, second grating layer; wherein,

The first lower separation confinement layer, the first quantum well, the first upper separation confinement layer and the first grating layer all belong to the first epitaxial region;

The second lower separation confinement layer, the second quantum well, the second upper separation confinement layer and the second grating layer all belong to the second epitaxial region.

Among them, in Figure 3, the upper and lower layers of the first quantum well use separate confinement layers, and the upper and lower layers of the second quantum well use separate confinement layers, which are defined according to the position distribution of the separation and confinement layers in the laser. It is the upper separation restriction layer and the lower separation restriction layer.

Further, in some embodiments of the present application, after step A4 is performed, the manufacturing method of the semiconductor laser device provided in the embodiments of the present application may further include the following steps:

A5. After the first grating layer is grown on the first upper separation limiting layer, a first grating is fabricated on the first grating layer, and the first grating belongs to the first laser;

A6. After the second grating layer is grown on the second upper separation limiting layer, a second grating is fabricated on the second grating layer, and the second grating belongs to the second laser.

Among them, the first grating is fabricated on the first grating layer 6 shown in FIG. 3, and the second grating is fabricated on the second grating layer 13. The first grating and the second grating are not shown in FIG. Note, it is not a limitation to the embodiments of the present application.

In some embodiments of the present application, step A3 performs selective etching on the right side of the second epitaxial structure to obtain the third epitaxial structure, the manufacturing method of the semiconductor laser device provided in the embodiments of the present application may further include the following steps:

A7. A protective layer is grown on the cap layer on the left side of the third epitaxial structure.

Wherein, the composition of the protective layer may be silicon dioxide, and the main function of this protective layer is to ensure that the part used to make the second n-electrode is not grown on the P-InP layer during the secondary epitaxy process.

In some embodiments of the present application, after step A7 grows a protective layer on the cap layer on the left side of the third epitaxial structure, the manufacturing method of the semiconductor laser device provided in the embodiments of the present application may further include the following steps:

A8. Perform a second epitaxy on the first grating layer and the second grating layer respectively, and grow a first contact layer on the first grating layer through the second epitaxy, and grow a second contact on the second grating layer Floor;

A9. The first ridge waveguide is etched from the first contact layer, and the second ridge waveguide is etched from the second contact layer. The first ridge waveguide belongs to the first epitaxial region, and the second ridge waveguide belongs to the second epitaxial region. ;among them,

The first contact layer is located between the first grating layer and the first p electrode;

The second contact layer is located between the second grating layer and the second p electrode.

In the embodiment of the present application, only two epitaxial growths are required in the manufacturing method of the semiconductor laser device. For details of the first epitaxial growth, please refer to the example of step A1 to step A7, and the second epitaxial growth is as in step A8. Through the second epitaxy, the first contact layer and the second contact layer can be grown. The contact layer can be made of P-InP material, and the ridge waveguide can be etched on the contact layer. For the manufacturing process and process of the ridge waveguide, this embodiment of the application No more detailed description in

In some embodiments of the present application, after step A9 etches the first ridge waveguide from the first contact layer and the second ridge waveguide is etched from the second contact layer, the semiconductor laser device provided by the embodiments of the present application The manufacturing method can also include the following steps:

A10. A first silicon dioxide layer is grown on the first grating layer and the first ridge waveguide, and a second silicon dioxide layer is grown on the second grating layer and the second ridge waveguide; wherein,

The first silicon dioxide layer belongs to the first epitaxial region, and the second silicon dioxide layer belongs to the second epitaxial region.

Wherein, the first laser includes a silicon dioxide layer, and the second laser also includes a silicon dioxide layer. Silicon dioxide is an insulating layer (also called a passivation layer) of the laser, which is mainly used to limit the current injection area.

Further, in some embodiments of the present application, in step A10, a first silicon dioxide layer is grown on the first grating layer and the first ridge waveguide, and a second silicon dioxide layer is grown on the second grating layer and the second ridge waveguide. After the silicon dioxide layer, the manufacturing method of the semiconductor laser device provided by the embodiment of the present application may further include the following steps:

A11. Clean the protective layer from the cover layer on the left side of the third epitaxial structure;

A12. The first silicon dioxide layer on the top of the first ridge waveguide is etched away, and the second silicon dioxide layer on the top of the second ridge waveguide is etched away.

Among them, the silicon dioxide on the top of the first ridge waveguide 16a and the second ridge waveguide 16b shown in FIG. 3 is etched away, so that the first p electrode 7 can be fabricated on the top of the first ridge waveguide 16a, and the second ridge waveguide A second p-electrode 14 is formed on the top of 16b. In Figure 3, only the top of the first ridge waveguide 16a, the top of the second ridge waveguide 16b, and the bottom of the second n-electrode 9 are not covered by silicon dioxide, so that the distribution of silicon dioxide ensures that the current injected into the second ridge waveguide 16b can only be From the second n-electrode 9, the current injected from the first ridge waveguide 16a can only flow from the first n-electrode 1. Therefore, the first laser and the second laser can have mutually isolated current channels, so that the two lasers can be independent Add modulated signal.

In some embodiments of the present application, the first p-electrode is located above the first silicon dioxide layer and above the top of the first ridge waveguide; the second p-electrode is located above the second silicon dioxide layer and is located Above the top of the second ridge waveguide.

Among them, after the silicon dioxide layer is windowed, the silicon dioxide on the top of the two ridge waveguides can be etched away, and the P electrode can be added to the top of the silicon dioxide layer, so that the P electrode can establish the hierarchical structure inside the laser The current channel.

In order to facilitate a better understanding and implementation of the above-mentioned solutions in the embodiments of the present application, the corresponding application scenarios are illustrated below for specific description.

In order to make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the following describes the embodiments of the present application in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the embodiments of the present application, and are not used to limit the embodiments of the present application.

The embodiment of the application provides a dual-wavelength laser of 1490 nm and 1577 nm. Among them, there are two lasers in the dual-wavelength laser, each laser includes a ridge waveguide, there are two sets of quantum wells under one ridge waveguide, and only one set of quantum wells exist under the other ridge waveguide; four of the two lasers The electrodes are completely separated, and each laser can independently add modulation signals. The dual-wavelength laser provided by the embodiment of the present application can not only realize wide-interval dual-wavelength lasing, but also realize independent tuning of two wavelengths, and has the advantages of compact structure and low cost.

In the embodiment of this application, the emission wavelength of the above-mentioned dual-wavelength laser can be 1490nm and 1577nm, but also applicable to other wavelengths. For example, any interval in the 1200-1700nm band can use the dual-wavelength provided by the embodiment of this application. The design scheme of the laser, but when the wavelength interval is small (for example, less than 20nm), the same quantum well can be used to achieve different wavelength production, and it is not necessary to use a dual laser structure.

With reference to FIG. 3, the structure of a dual-wavelength laser of 1490 nm and 1577 nm will be described next. FIG. 3 shows a cross-sectional view of the laser. From bottom to top, the dual-wavelength laser includes: first n-electrode 1, substrate layer 2 (n-InP1), first lower separation and confinement layer 3 (SCH1), multiple quantum well 14 (MQWs 1), first upper separation and confinement layer 5 (SCH2), the first grating layer 6 (the grating layer 1), the first p electrode 7, the cap layer (for example, the cap layer includes n-InP28a and I-InP8b), the second n electrode 9, the second lower separation confinement layer 10 (SCH3), second active region 11 (MQWs 2), second upper separation confinement layer 12 (SCH4), second grating layer 13 (grating layer 2), second p-electrode 14, silicon dioxide layer (including 15a and 15b in FIG. 3), contact layer (including 16a and 16b in FIG. 3).

Wherein, the capping layer may include an n-InP layer and an I-InP layer. The capping layer and the reference numerals 9-14, 15b, and 16b above constitute a complete second laser structure. The reference numerals below the capping layer The layers 1-7, 15a, and 16a together form a complete first laser structure, and the two lasers are attached to the same substrate layer n-InP1. The current generated by the second signal is injected from the second ridge waveguide (W2), and finally flows out from the second n-electrode 9 through the cap layer, without passing through the epitaxial region 1-6 below. Similarly, the current generated by the first signal is from the first A ridge waveguide (W1) is injected, and finally flows out from the first n-electrode 1 through the substrate layer 2, so the first laser and the second laser have separate current channels.

The laser on the left shown in FIG. 3 is the second laser, which may include structures numbered 8-14, 15b, and 16b, and the laser on the right shown in FIG. 3 is the first laser, which may include structures numbered 1- 7. The structure of 15a, 16a. Among them, 15a on the right and 15b on the left in Figure 3 grow together, and 15a on the right and 15b on the left in Figure 3 grow together. Although the second laser has structures 1-6 underneath, the first The work of the second laser has nothing to do with the first laser, and the first laser only serves as a bearing platform. Similarly, the operation of the first laser has nothing to do with the second laser.

In the embodiment of this application, the four electrodes of the two lasers are completely separated, the second n-electrode 9 and the second p-electrode 14 together form the electrodes required by the second active region 11 (MQWs 2), the first n-electrode 1 and The first p-electrodes 7 jointly form the electrodes required by the first active region 4 (MQWs 1). Each laser can add modulation signals independently, without crosstalk between each other.

Among them, silicon dioxide is an insulating layer (also called a passivation layer), which is mainly used to limit the current injection area. Only the upper part of the ridge waveguide (W1, W2) and the second n electrode 9 are not covered by silicon dioxide. Such a distribution of silicon dioxide ensures that the current injected on W2 can only flow from the second n-electrode 9 and the current injected from W1 can only flow from the first n-electrode 1.

In the embodiment of the present application, the widths of the two ridge waveguides are W1 and W2 respectively, and the distance between the two ridge waveguides can be adjusted according to actual requirements and process conditions. From the cross-sectional view shown in Figure 3, it can be seen that there are two active regions (MQWs 1 and MQWs 2) under one ridge waveguide, and only one active region (MQWs 1) exists under the other ridge waveguide. The difference is The lasing wavelength of the source region is different, and the lasing wavelength of the active region (i.e., quantum well) is related to the material composition of the active region. In the dual-wavelength laser structure provided by the embodiment of this application, the two quantum wells use different The material composition can therefore achieve different lasing wavelengths.

In the embodiment of the present application, the two lasers in the dual-wavelength laser can independently perform signal modulation, which is determined by the overall design structure. The cap layer includes an n-InP layer and an I-InP layer, and the reference number above is Layers 9-14, 15b, and 16b together form a complete laser structure. Current is injected from the second ridge waveguide (W2), and finally flows out from the second n-electrode 9 through the cap layer. The current does not pass through the epitaxial regions 1-6 below, and is also independent of the first ridge waveguide (W1) and the second p-electrode 7 on the right. The first n-electrode 1 and the epitaxial region 2-6, the second p-electrode 7, and the first ridge waveguide (W1) together form a complete laser structure. Current is injected from the first ridge waveguide (W1) through the epitaxial region 6-2 and finally It flows out from the first n electrode 1. There is no overlap between the current flow paths of the two lasers, so there is no crosstalk between each other, and modulation signals can be added independently.

From the above example of dual-wavelength lasers, it can be seen that the two lasers included in the dual-wavelength lasers in the embodiments of the present application do not share other epitaxial region structures except that they are attached to the same substrate. Therefore, the two lasers can be operated according to their own characteristics. Independent optimization design helps to improve the performance index of the laser.

It should be noted that both lasers are grown on the same substrate layer 2, and the cap layer 8 includes: an n-InP layer and an I-InP layer. Among them, the n-InP layer can be used to form the PIN junction of the second laser. Below the n-InP layer is an undoped I-InP layer. The resistance of the I-InP layer is relatively large, which can effectively avoid the second p The current of the electrode 1022 flows to the first laser 101.

Next, the manufacturing method of the dual-wavelength laser will be illustrated by an example. For example, the manufacturing method of the dual-wavelength laser of 1490nm and 1577nm is taken as an example, which mainly includes the following steps:

Step S1, epitaxy once, grow two sets of quantum wells on the substrate, as well as the upper separation confinement layer, the lower separation confinement layer, and the grating layer required by the dual-wavelength laser;

Step S2, selective etching, etching the selected area to the n-InP layer close to the MQWs 2;

Step S3, further selective etching, etching off the n-InP layer on one side;

Step S4, making gratings for the two sets of quantum wells;

Step S5, secondary epitaxial growth of the contact layer;

Step S6: Complete the ridge of the laser, open the window, and fabricate the four electrodes of the dual-wavelength laser.

Specifically, in the manufacturing process from step S1 to step S6 above, please refer to FIG. 5a to FIG. 5g.

First, please refer to Figure 5a, an epitaxy is performed on an n-InP substrate. The epitaxial material includes a first lower separation confinement layer 3 (SCH1), a first active region 4 (MQWs 1), and a first upper separation confinement layer 5 (SCH2), the first grating layer 6 (grating layer 1), the cover layer (n-InP28a and I-InP8b), the second n electrode 9, the second lower separation confinement layer 10 (SCH3), the second active region 11 (MQWs 2), the second upper separation limiting layer 12 (SCH4), and the second grating layer 13 (grating layer 2).

As shown in Fig. 5b, the epitaxial area of the selected area is etched to the cap layer by using the selected area etching technique.

As shown in Figure 5c, a second selective etching is then performed to etch away the cap layer on one side.

As shown in Figure 5d, a protective layer is then grown on the cover layer. The protective layer is usually composed of silicon dioxide. The main function of this protective layer is to ensure that the left side is used to make the second n-electrode during the secondary epitaxy process. The part of 9 is not grown on the P-InP layer. Fabricate a grating suitable for the first active region (MQWs 1) on the first grating layer 6 (grating layer 1), fabricate a grating suitable for the second active region (MQWs 2) on the second grating layer 13 (grating layer 2) ) Of the raster.

As shown in FIG. 5e, after the cleaning of the wafer is completed, the selected area is epitaxy, and the upper contact layer P-InP is grown on the area except the cap layer whose surface is n-InP. The growth of the contact layer P-InP is on the upper surface of the grating 1 and the grating 2, but on the grating 1 and the grating 2. The cover layer (n-InP and I-InP) has a protective layer, so this area is not processed Grow.

As shown in Figure 5f, the ridge waveguides of the two lasers are then etched, and a silicon dioxide layer 15 is grown on the entire wafer.

As shown in Figure 5g, the next windowing operation is performed to etch away the silicon dioxide on the top of the two ridge waveguides and clean the protective layer on the cap layer.

As shown in Figure 3, the first p-electrode 7, the second n-electrode 9, and the second p-electrode 14 are finally fabricated on the front surface of the wafer, and then the n-InP substrate layer 2 is thinned, and finally the substrate layer 2 The first n electrode 1 is made on the back side. The thinning is the n-InP substrate layer 2. After the thinned n-InP substrate, the first n-electrode can be fabricated. The wafer process can be used to finally cleave the wafer into individual lasers. The substrate will bring cleavage difficulties, and only the substrate can be thinned to meet the accuracy and requirements of cleavage.

The embodiment of the application has completed the fabrication of a wide-spaced dual-wavelength laser on the same substrate through two epitaxial growth. The two dual-wavelength lasers are arranged side by side and are arranged in different heights. In order to ensure the epitaxial quality of the two quantum wells, it is necessary to The delay completes the growth of the two quantum wells, but only quantum well 2 is used when the left laser is working, and only quantum well 1 is used when working on the right. When making the right laser, the part related to the quantum well 2 will be etched away, so it will be shorter than the ridge waveguide on the left, and will eventually form a shape of staggered height without the same height. There are two active areas under a laser ridge waveguide, and only one active area under a laser. Except for being attached to the same substrate, the two lasers do not share other epitaxial structure, and the four electrodes of the two lasers are completely separate. This structural feature allows the dual-wavelength laser to complete the growth of two active regions in a single epitaxial growth, and then part of the active region is etched away by selective etching, and different active regions are used to make a wide wavelength The spaced dual-wavelength laser reduces the number of epitaxy, which is beneficial to improve the performance index and yield of the laser, and reduce the production cost of the laser. Four completely separated electrodes ensure that the two lasers can work independently and add modulation signals. The two lasers do not share other epitaxial regions except for the substrate, so the design of the two lasers can be optimized independently, which helps to improve and improve the performance indicators of the lasers.

The above are only specific implementation manners of the embodiments of the present application, and are not used to limit the embodiments of the present application. The embodiments of the present application can be used for all dual-wavelength laser designs, and are not limited to only the communication band. The wavelength range of the foregoing examples in the embodiments of the present application is any wavelength interval within 1200-1600 nm. If another substrate is used, it can also cover all wavelength bands that can be grown on other substrates.

It should be noted that the semiconductor laser device provided in the embodiments of the present application is also applicable to multi-wavelength lasers, such as lasers with three or four active regions, for example, multi-wavelength lasers with a wavelength range of 1200-1600 nm.

It should be noted that for the foregoing methods, for the sake of simple description, they are all expressed as a series of action combinations, but those skilled in the art should know that this application is not limited by the described sequence of actions, because according to this For application, some steps can be performed in other order or at the same time. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by this application.

In addition, it should be noted that the device embodiments described above are merely illustrative, and the units described as separate components may or may not be physically separated, and the components displayed as units may or may not The physical unit can be located in one place or distributed across multiple units. Some or all of the modules can be selected according to actual needs to achieve the objectives of the solutions of the embodiments.

Claims

A semiconductor laser device, characterized in that, the semiconductor laser device comprises: a first laser and a second laser, wherein:

The first laser and the second laser are attached to the same substrate layer;

The n electrode of the first laser and the n electrode of the second laser are independent of each other, and the p electrode of the first laser and the p electrode of the second laser are independent of each other;

When the first signal is added to the electrode of the first laser, the current generated in the first laser forms a first current channel, and when the second signal is added to the electrode of the second laser, the current generated in the second laser Forming a second current channel, the modulation of the first laser by the first signal and the modulation of the second laser by the second signal are independent of each other;

The second laser includes a cap layer for achieving mutual isolation between the first current channel and the second current channel.
The semiconductor laser device according to claim 1, wherein the first laser comprises: a first n electrode and a first p electrode;

The second laser includes: a second n electrode and a second p electrode;

The first signal is injected into the first laser from the first p electrode and output from the first n electrode;

The second signal is injected from the second p-electrode to the second laser and output from the second n-electrode.
The semiconductor laser device according to claim 2, wherein the first laser further comprises: a first epitaxial region, and the first n-electrode and the first p-electrode are located on two sides of the first epitaxial region. end;

The second laser further includes: a second epitaxial region, the second n electrode and the second p electrode are located at both ends of the second epitaxial region; the second n electrode, the second p electrode Located on the same side of the cap layer as the second epitaxial region;

The first epitaxial region and the second epitaxial region are separated from each other by the cap layer, and the first epitaxial region and the second epitaxial region are located on both sides of the cap layer.
The semiconductor laser device according to claim 3, wherein the first epitaxial region comprises: a first quantum well; the second epitaxial region comprises: a second quantum well, the first quantum well and the The second quantum well is formed by the same epitaxial growth;

The first quantum well, the first p-electrode, the second n-electrode, the second quantum well, the second p-electrode and the cap layer are all located above the substrate layer;

The first n electrode is located under the substrate layer;

The first p electrode is located above the first quantum well;

The cap layer is located between the first quantum well and the second quantum well;

The second n electrode is located below the second quantum well, and the second p electrode is located above the second quantum well;

The first p electrode and the second n electrode are separated by the cap layer;

The first p-electrode and the second p-electrode are separated by the cap layer and the second quantum well.
The semiconductor laser device according to claim 4, wherein the first epitaxial region further comprises: a first lower separation confinement layer and a first upper separation confinement layer; the second epitaxial region further comprises: a second lower Separation restriction layer, the second upper separation restriction layer; among them,

The first lower separation confinement layer is located between the substrate layer and the first quantum well;

The first upper separation confinement layer is located above the first quantum well and below the cap layer;

The second lower separation confinement layer is located between the cap layer and the second quantum well;

The second upper separation confinement layer is located above the second quantum well.
The semiconductor laser device according to claim 5, wherein the first epitaxial region further comprises: a first grating layer; the second epitaxial region further comprises: a second grating layer; wherein,

A first grating is fabricated on the first grating layer, and a second grating is fabricated on the second grating layer;

The first grating layer is located above the first upper separation limiting layer;

The second grating layer is located above the second upper separation limiting layer;

The cap layer is located above the first grating layer.
8. The semiconductor laser device of claim 6, wherein the first epitaxial region further comprises: a first contact layer, and the first contact layer comprises: a first ridge waveguide;

The second epitaxial region further includes: a second contact layer, and the second contact layer includes: a second ridge waveguide;

The first contact layer is located between the first grating layer and the first p electrode;

The second contact layer is located between the second grating layer and the second p electrode.
7. The semiconductor laser device according to claim 7, wherein the first epitaxial region further comprises: a first silicon dioxide layer; the second epitaxial region further comprises: a second silicon dioxide layer; wherein,

The first silicon dioxide layer is located on the end surface of the first ridge waveguide, and the first silicon dioxide layer is located between the first grating layer and the first p electrode;

The second silicon dioxide layer is located on the end surface of the second ridge waveguide, and the second silicon dioxide layer is located between the second grating layer and the second p-electrode.
8. The semiconductor laser device of claim 7, wherein the first ridge waveguide and the second ridge waveguide have the same thickness;

The lowest plane where the first ridge waveguide is located is lower than the lowest plane where the second ridge waveguide is located.
The semiconductor laser device according to any one of claims 1 to 9, wherein the first laser and the second laser are arranged side by side on the substrate layer.
The semiconductor laser device according to any one of claims 1 to 10, wherein the second laser is superimposed on the first laser, and the first laser is provided on the substrate layer.
A multi-wavelength laser, characterized in that the multi-wavelength laser comprises: the semiconductor laser device according to any one of claims 1 to 10.
A semiconductor chip, wherein the semiconductor chip comprises: the semiconductor laser device according to any one of claims 1 to 10.
An optical module, characterized in that, the optical module comprises: the semiconductor laser device according to any one of claims 1 to 10.
An optical line terminal, characterized in that the optical line terminal comprises: the optical module according to claim 14.
An optical network unit, characterized in that the optical network unit comprises: the optical module according to claim 14.
A method for manufacturing a semiconductor laser device, characterized in that the method includes:

The first laser and the second laser are respectively fabricated on the same substrate layer. The second laser includes a cap layer. The first current channel of the first laser and the second laser of the second laser are connected through the cap layer. The current channels are isolated from each other;

The first laser and the second laser are configured with mutually independent n electrodes, and the first laser and the second laser are configured with mutually independent p electrodes.
The method according to claim 17, wherein said separately fabricating the first laser and the second laser on the same substrate layer comprises:

Perform a first epitaxial on the front surface of the substrate layer, and grow a first epitaxial structure through the first epitaxial growth. The first epitaxial structure includes the following hierarchical structure from bottom to top: the first epitaxial region, the A cap layer and a second epitaxial region, wherein the first epitaxial region belongs to the first laser, and the second epitaxial region belongs to the second laser;

Performing selective etching on the left and right sides of the first epitaxial structure to obtain a second epitaxial structure;

Perform selective etching on the right side of the second epitaxial structure to obtain a third epitaxial structure. The cap layer on the right side of the third epitaxial structure is etched away. The cover layer remains on the left side.
18. The method of claim 18, wherein the first laser and the second laser are configured with mutually independent n electrodes, and the first laser and the second laser are configured with independent n electrodes. The p-electrode includes:

Fabricating a first p-electrode above the first epitaxial region;

Fabricating a second p-electrode above the second epitaxial region;

Fabricating a second n electrode on the cover layer on the left side of the third epitaxial structure, wherein the second n electrode and the second p electrode belong to the second laser;

The back surface of the substrate layer is thinned, and a first n electrode is fabricated on the back surface of the substrate layer, wherein the first n electrode and the first p electrode belong to the first laser.
18. The method according to claim 19, wherein the performing the first epitaxial growth on the front surface of the substrate layer and growing the first epitaxial structure through the first epitaxial growth further comprises:

The first epitaxial growth is performed on the front surface of the substrate layer, and the first lower separation confinement layer, the first quantum well, the first upper separation confinement layer, the first grating layer, the cap layer, and the second lower Separation confinement layer, second quantum well, second upper separation confinement layer, second grating layer; wherein,

The first lower separation confinement layer, the first quantum well, the first upper separation confinement layer and the first grating layer all belong to the first epitaxial region;

The second lower separation confinement layer, the second quantum well, the second upper separation confinement layer, and the second grating layer all belong to the second epitaxial region.