Optical gain chip, device and manufacturing method

Abstract

The invention provides an optical gain chip, an optical gain device and a manufacturing method, the optical gain chip comprises a bottom electrode, a substrate, a limiting layer, an active layer, a waveguide layer and a top electrode which are stacked in sequence, and the waveguide layer is partially etched to form a ridge waveguide. And the light outlet of the ridge waveguide is enclosed in the first groove, the second groove and the third groove, so that the light signal emitted by the ridge waveguide can be far away from the ridge waveguide as far as possible after being reflected, and the phenomenon of secondary coupling is avoided. In addition, the device has the advantages of being excellent in effect and simple in structure.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor processing, and in particular to an optical gain chip, a device and a manufacturing method. Background Art

[0002] Optical gain chips are important optical chips with widespread applications in optical imaging, optical communications, optical sensing, and other fields. Common optical gain chips include superluminescent diodes and semiconductor optical amplifiers. Optical gain chips must prevent photons output from the chip from reflecting and re-entering the chip. This is because the reflected light signal resonates within the chip, forming mode-selective spectral ripples. This formation can seriously interfere with the spectral frequency stability of the chip product in subsequent applications.

[0003] To suppress resonance within the gain chip and reduce spectral ripple, the reflectivity at the target wavelength at the chip's light output must be less than 0.0001. Existing technologies typically achieve this reflectivity through cavity surface coating, requiring film thickness control accuracy to within 2nm. However, this is extremely challenging given the stability of the coating machine and the product yield requirements.

[0004] To more effectively and stably reduce the spectral ripples generated by resonance within the gain chip, one approach is to use an angled ridge waveguide or end-bent waveguide structure within the gain chip, preventing most of the emitted photons from being reflected back into the waveguide as in conventional lasers. However, because ridge waveguides are weakly optically confined structures, a small portion of the deflected reflected light field will still be scattered again and coupled into the ridge waveguide. This weak secondary coupling light field will also cause device resonance, interfering with subsequent applications.

[0005] Therefore, how to design an optical gain chip and device that deflects the light field as much as possible to avoid secondary coupling has become one of the urgent problems to be solved by those skilled in the art.

[0006] It should be noted that the above technical background is merely provided to provide a clear and complete description of the technical solutions of the present invention and to facilitate understanding by those skilled in the art. Simply because these solutions are described in the technical background section of the present invention, it should not be assumed that the above technical solutions are well known to those skilled in the art. Summary of the Invention

[0007] In view of the above-mentioned shortcomings of the prior art, the object of the present invention is to provide an optical gain chip, a device and a manufacturing method for solving the problem that the secondary coupling phenomenon of the light field in the optical gain chip of the prior art is still relatively obvious.

[0008] To achieve the above objectives and other related objectives, the present invention provides an optical gain chip, comprising at least: a bottom electrode, a substrate, a confinement layer, an active layer, a waveguide layer, and a top electrode; the substrate is disposed on the bottom electrode, serving as a base of the optical gain chip; the confinement layer is disposed on the substrate and is configured to confine optical signals generated by the active layer from entering the substrate; the active layer is disposed on the confinement layer and is configured to generate optical signals; the waveguide layer is disposed on the active layer and is configured to receive optical signals from the active layer and output optical signals; the waveguide layer is partially etched to form a first groove and a second groove; a ridge waveguide is formed between the first groove and the second groove, the ridge waveguide guiding the transmission of the optical signal generated by the active layer, the thickness of the ridge waveguide varying monotonically along the transmission direction of the optical signal; one end of the ridge waveguide serves as a light-emitting surface; the waveguide layer on one side of the light-emitting surface is partially etched to form a third groove; the light-emitting surface having the third groove formed therein after the partial etching serves as a light-emitting port of the ridge waveguide; and the top electrode is disposed on the waveguide layer.

[0009] Optionally, the first groove, the second groove and the third groove are connected to each other.

[0010] Optionally, the area where the light outlet outputs the optical signal is a light exit area, and after the active layer in the light exit area is etched, the waveguide layer is partially disposed on the upper surface of the confinement layer.

[0011] More optionally, the etching length of the active layer in the optical signal transmission direction is 10 μm-30 μm.

[0012] Optionally, the area where the light outlet outputs the optical signal is a light output area, and after the top electrode in the light output area is etched, the upper surface of the waveguide layer is partially exposed.

[0013] More optionally, the etching length of the top electrode in the optical signal transmission direction is 10 μm-30 μm.

[0014] More optionally, the etching shape of the top electrode in the light emitting region is a trapezoid; the side length of the trapezoid close to the light emitting side is greater than the side length away from the light emitting side.

[0015] Optionally, an angle between an end face of the first groove on the light-emitting side and the propagation direction of the optical signal is 0 degrees to 90 degrees.

[0016] Optionally, an angle between an end face of the second groove located on the light-emitting side and the propagation direction of the optical signal is 0 degrees to 90 degrees.

[0017] Optionally, a first input / output port and a second input / output port are respectively provided at both ends of the ridge waveguide, and the light output port is any one of the first input / output port or the second input / output port.

[0018] To achieve the above-mentioned object and other related objects, the present invention further provides an optical gain device, which includes: a cavity and the optical gain chip; the optical gain chip is disposed in the cavity.

[0019] To achieve the above-mentioned and other related objectives, the present invention further provides a method for manufacturing an optical gain chip, comprising at least the following steps: S1: providing a bottom electrode, with a substrate formed on the bottom electrode; S2: sequentially forming a stacked confinement layer, an active layer, and a waveguide layer on the substrate; wherein the thickness of the waveguide layer varies monotonically along the direction of the optical signal; S3: partially etching the waveguide layer to obtain a first trench and a second trench with reduced thickness; forming a ridge waveguide between the first trench and the second trench, etching one end of the ridge waveguide to form a light-emitting surface, and partially etching the waveguide layer on one side of the light-emitting surface to obtain a third trench with reduced thickness; and S4: forming a top electrode on the waveguide layer.

[0020] Optionally, in step S2, before the waveguide layer is formed, the active layer in the light exit area is etched so that the waveguide layer is partially disposed on the upper surface of the confinement layer.

[0021] Optionally, in step S4, after the top electrode is formed, the top electrode in the light output region is etched so that the upper surface of the waveguide layer is partially exposed.

[0022] Optionally, in step S3, the end face of the first groove on the light emitting side is etched so that the end face of the first groove on the light emitting side forms an angle with the propagation direction of the optical signal; the end face of the second groove on the light emitting side is etched so that the end face of the second groove on the light emitting side forms an angle with the propagation direction of the optical signal.

[0023] As described above, the optical gain chip, device, and manufacturing method of the present invention have the following beneficial effects:

[0024] 1. In the present invention, the waveguide layer on one side of the light-emitting surface of the ridge waveguide is etched to form a third groove, and the first groove, the second groove and the third groove structurally enclose the light-emitting surface of the ridge waveguide, so that the reflected light cannot enter the ridge waveguide, which can avoid the secondary coupling phenomenon as much as possible and improve the quality of the optical gain chip output light signal.

[0025] 2. The present invention etches the active layer in the light output region to prevent the material of the active layer from dripping and affecting the output optical signal of the waveguide layer, thereby further improving the quality of the output optical signal.

[0026] 3. The present invention etches the top electrode in the light-emitting region to prevent the top electrode material from dripping and affecting the output optical signal of the waveguide layer, thereby further improving the quality of the output optical signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Shown is a schematic structural diagram of the optical gain chip of the present invention.

[0028] Figure 2 It shows a first schematic top view of the active layer of the present invention.

[0029] Figure 3 A first schematic top view of the ridge waveguide, the first trench, the second trench, and the third trench of the present invention is shown.

[0030] Figure 4 It is a schematic diagram showing the effect of the ridge wave output optical port shielding the reflected light signal according to the present invention.

[0031] Figure 5 The diagram shows the effect of shielding reflected optical signals using a common ridgewave optical port.

[0032] Figure 6 It is a schematic diagram showing the first etching width of the third trench of the present invention.

[0033] Figure 7 A first schematic top view of the top electrode of the present invention is shown.

[0034] Figure 8 The figure shows a comparison of the reflected light field effects of a common optical gain chip and the optical gain chip of the present invention.

[0035] Figure 9 A first top view of the active layer, waveguide layer, and top electrode of the optical gain chip of the present invention is shown.

[0036] Figure 10 A second top view of the active layer, waveguide layer, and top electrode of the optical gain chip of the present invention is shown.

[0037] Figure 11 A second schematic top view of the ridge waveguide, the first trench, the second trench, and the third trench of the present invention is shown.

[0038] Figure 12 It is a schematic diagram showing a second etching method for the third trench of the present invention.

[0039] Figure 13 It shows a second schematic top view of the active layer of the present invention.

[0040] Figure 14 A second schematic top view of the top electrode of the present invention is shown.

[0041] Figure 15 It is a schematic structural diagram of the cavity of the optical gain device of the present invention.

[0042] Figure 16 It is a schematic flow chart showing the method for manufacturing the optical gain chip of the present invention.

[0043] Component number description

[0044] 1 Optical Gain Chip

[0045] 11 bottom electrode

[0046] 12 substrate

[0047] 13 Restriction Layer

[0048] 14 Active layer

[0049] 15 waveguide layer

[0050] 16 Top electrode

[0051] 1a First groove

[0052] 1b Second groove

[0053] 1c Ridge waveguide

[0054] 1c1 light-emitting surface

[0055] 1d Third groove

[0056] 2 Cavity DETAILED DESCRIPTION

[0057] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0058] See also Figures 1-16 It should be noted that the diagrams provided in this embodiment are merely schematic illustrations of the basic concept of the present invention. Therefore, the diagrams only show components related to the present invention and are not drawn according to the number, shape, and size of components in actual implementation. In actual implementation, the type, quantity, and proportion of each component may be changed arbitrarily, and the component layout may also be more complex.

[0059] Example 1

[0060] like Figure 1As shown, this embodiment provides an optical gain chip 1 , which includes a bottom electrode 11 , a substrate 12 , a confinement layer 13 , an active layer 14 , a waveguide layer 15 and a top electrode 16 .

[0061] like Figure 1 As shown, a substrate 12 is provided on the bottom electrode 11 , and the substrate 12 serves as a base of the optical gain chip 1 .

[0062] Specifically, in this embodiment, bottom electrode 11 serves as the electrical channel entrance for the optical gain chip. Carriers are injected into bottom electrode 11, while carriers different from those injected into top electrode 16 are injected. These two carriers generate optical signals in the active layer (all layers between the bottom and top electrodes are made of conductive materials). Furthermore, substrate 12 serves as a base for the subsequent layers to grow. For example, gallium arsenide, potassium carbide, or indium phosphide can be used as the material for substrate 12. In practical applications, the specific material for substrate 12 is selected based on actual needs and is not limited to this embodiment.

[0063] like Figure 1 As shown, the confinement layer 13 is disposed on the substrate 12 to confine the optical signal generated by the active layer 14 from entering the substrate 12 .

[0064] Specifically, in this embodiment, the confinement layer 13 is located between the substrate 12 and the active region 14, and can confine carriers in the active region 14 within the active region 14, thereby preventing the optical signal generated by the active region 14 from entering the substrate 12. As an example, the material of the confinement layer 13 can be indium phosphide or indium aluminum arsenide. In actual applications, the specific material of the confinement layer 13 can be selected as needed and is not limited to this embodiment.

[0065] like Figure 1 As shown, the active layer 14 is disposed on the confinement layer 13 for generating an optical signal.

[0066] Specifically, in this embodiment, the active layer 14 is typically formed of a quantum well or barrier structure. Carriers recombine in the active layer 14 to generate photons, thereby enabling the active region 14 to generate optical signals. Furthermore, because the quantum well structure enhances the recombination efficiency of electrons and holes, the active layer 14 can improve the gain bandwidth. As an example, the material of the active layer 14 can be indium gallium arsenide or indium gallium arsenide phosphide. In actual applications, the specific material of the active layer 14 is selected based on actual needs and is not limited to this embodiment.

[0067] Specifically, in this embodiment, the area where the optical signal is output from the optical gain chip 1 is the light-exiting area. The light-exiting area, i.e., the area around the light outlet, will affect the light-exiting area of ​​the ridge waveguide 1c. The metal drop of the active layer 14 in the light-exiting area may affect the light output of the ridge waveguide 1c. Therefore, the active layer 14 in the light-exiting area needs to be etched. Figure 1 As shown, after the active layer 14 in the light-emitting region is etched, the waveguide layer 15 is partially disposed on the upper surface of the confinement layer 13, and as shown in FIG. Figure 2 As shown, the etching length (etching size) of the active layer 14 in the optical signal transmission direction (the optical signal transmission direction is the direction in which the optical signal is output in the ridge waveguide 1c toward the light outlet) is 10μm-30μm, including but not limited to 12μm, 14μm, 15μm, 16μm, 18μm, 20μm, 22μm, 24μm, 25μm, 26μm, and 28μm. At the same time, the specific etching area of ​​the active layer 14 should be slightly larger than the specific area of ​​the ridge waveguide light outlet, so that the vertical projection of the ridge waveguide light outlet is located within the vertical projection of the etched surface of the active area. In actual applications, the specific etching size of the active layer 14 is set as needed, which is not limited to this embodiment.

[0068] like Figure 1 As shown, the waveguide layer 15 is provided on the active layer 14 for receiving the optical signal of the active layer 14 and outputting the optical signal; the waveguide layer 15 is partially etched to form a first groove 1a and a second groove 1b, and a ridge waveguide 1c is formed between the first groove 1a and the second groove 1b. The ridge waveguide 1c guides the transmission of the optical signal generated by the active layer 14, and the thickness of the ridge waveguide 1c varies monotonically along the transmission direction of the optical signal; one end of the ridge waveguide 1c is a light-emitting surface, and the waveguide layer 15 on the side of the light-emitting surface 1c1 is partially etched to form a third groove 1d, and the light-emitting surface having the third groove after partial etching is a light-emitting port of the ridge waveguide.

[0069] Specifically, in this embodiment, the optical signal generated by the active layer 14 enters the waveguide layer 15, and the waveguide layer 15 guides the optical signal to be output outside the optical gain chip 1. Furthermore, after the waveguide layer 15 is partially etched, a first trench 1a and a second trench 1b with a reduced thickness are formed (the specific reduced thickness of the two trenches is set according to the required thickness of the ridge waveguide 1c), as shown in FIG. Figure 3 As shown, a ridge waveguide 1c is formed between the first groove 1a and the second groove 1b. The ridge waveguide 1c guides the optical signal to be transmitted in the ridge waveguide, and the optical signal is output from the light outlet at one end of the ridge waveguide 1c. The thickness of the ridge waveguide 1c changes monotonically along the transmission direction of the optical signal, that is, the ridge waveguide 1c is a tilted ridge waveguide. Furthermore, as shown in FIG. Figure 3 As shown, the ridge waveguide is further etched on the side of the light-emitting surface 1c1 to form a third groove 1d, and the first groove 1a, the second groove 1b and the third groove 1d are interconnected. Therefore, as shown in FIG. Figure 4As shown, the light outlet of the ridge waveguide 1c is located in the area enclosed by the first groove 1a, the second groove 1b and the third groove 1d. When the light signal emitted by the ridge waveguide 1c is reflected, the first groove 1a, the second groove 1b and the third groove 1d can jointly protect the light signal output by the ridge waveguide from entering the ridge waveguide 1c after being reflected. Figure 5 Compared with the traditional ridge waveguide, this embodiment can avoid the occurrence of secondary coupling as much as possible. Furthermore, the wider the etching width of the third groove 1d, the more it can ensure that the ridge waveguide 1c is away from the reflection surface, thus avoiding the occurrence of secondary coupling. Figure 6 As shown, the etching length (etching size) of the third trench 1d in the optical signal transmission direction is 5-50μm, including but not limited to 6μm, 7μm, 8μm, 9μm, 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, and 45μm. In actual applications, the etching width of the third trench 1d can be set as needed and is not limited to this embodiment.

[0070] Specifically, in this embodiment, Figure 3 As shown, the angle θ1 between the end face of the first groove 1a on the light-emitting side and the propagation direction of the optical signal is greater than 0 degrees and less than 90 degrees, including but not limited to 10 degrees, 20 degrees, 30 degrees, 40 degrees, 50 degrees, 60 degrees, 70 degrees, and 80 degrees; wherein the purpose of setting the angle θ1 is that the first groove 1a with the angle θ1 can make the optical signal output from the light outlet further away from the ridge waveguide 1c. Further, as Figure 3 As shown, the angle θ2 between the end face of the second groove 1b on the light-emitting side and the optical signal propagation direction is greater than 0 degrees and less than 90 degrees, including but not limited to 10 degrees, 20 degrees, 30 degrees, 40 degrees, 50 degrees, 60 degrees, 70 degrees, and 80 degrees. The purpose of setting the angle θ2 is to allow the second groove 1b with the angle θ2 to further move the optical signal output from the light outlet away from the ridge waveguide 1c. In actual applications, the specific ranges of the angle θ1 between the end face of the first groove 1a and the optical signal propagation direction and the specific ranges of the angle θ2 between the end face of the second groove 1b and the optical signal propagation direction can be set as needed, and are not limited to this embodiment.

[0071] like Figure 1 As shown, the top electrode 16 is disposed on the waveguide layer 15 .

[0072] Specifically, in this embodiment, the top electrode 16 is disposed on the waveguide layer 15 and is also the electrical channel entrance of the optical gain chip 1. Furthermore, the region where the waveguide layer 15 outputs the optical signal is the light-emitting region. Since the metal drop of the top electrode 16 in the light-emitting region may affect the light output from the light outlet, the top electrode 16 in the light-emitting region needs to be etched. Furthermore, after the top electrode 16 in the light-emitting region is etched, the upper surface of the waveguide layer 15 is partially exposed, and as shown in FIG. Figure 7 As shown, the etching length (etching size) of the top electrode 16 in the direction of optical signal transmission is 10μm-30μm, including but not limited to 12μm, 14μm, 15μm, 16μm, 18μm, 20μm, 22μm, 24μm, 25μm, 26μm, and 28μm. At the same time, the specific etching area of ​​the top electrode 16 should be slightly larger than the specific area of ​​the ridge waveguide light outlet, so that the vertical projection of the ridge waveguide light outlet is located within the vertical projection of the etching surface of the top electrode. In practical applications, the specific etching size of the top electrode 16 is set as needed, which is not limited to this embodiment. Furthermore, as Figure 1 and Figure 7 As shown, the etching shape of the top electrode 16 in the light-emitting area is a trapezoid. Along the propagation direction of the optical signal, the side length of the trapezoid close to the light-emitting side is greater than the side length of the light-emitting side. That is, as the optical signal propagates, more parts of the top electrode 16 are etched away, which is more conducive to the light output of the optical gain chip 1. In practical applications, the etching shape of the top electrode 16 is set according to actual needs and is not limited to this embodiment.

[0073] It should be noted that, as an example, Figure 9 and Figure 10 As shown, the optical gain chip 1 of this embodiment is composed of a bottom electrode 11, a substrate 12, a confinement layer 13, an active layer 14, a waveguide layer 15, and a top electrode 16. Furthermore, since the light-emitting surface 1c1 of the ridge waveguide 1c is protected by the first groove 1a, the second groove 1b, and the third groove 1d, compared to a conventional gain chip, this embodiment can make the optical signal output by the ridge waveguide be reflected further away from the ridge waveguide 1c, thus avoiding the occurrence of secondary coupling. Figure 8 As shown, compared with ordinary gain chips, the optical gain chip 1 of this embodiment can reduce the generation of clutter and better concentrate the wave intensity on the target reflection angle.

[0074] Example 2

[0075] like Figure 11 As shown, this embodiment provides an optical gain chip 1. The difference between this embodiment and the first embodiment is that the two ends of the ridge waveguide 1c are respectively the first input and output port and the second input and output port; the light output port is any one of the first input and output port or the second input and output port.

[0076] Specifically, in this embodiment, Figure 11As shown, the two ends of the ridge waveguide 1c are respectively the first input / output port and the second input / output port. Both the first input / output port and the second input / output port can be used as light output ports: when the first input / output port is used as the light output port (in this case, the light signal transmission direction points to the first input / output port), the second input / output port is used as the light input port; when the second input / output port is used as the light output port (in this case, the light signal transmission direction points to the second input / output port), the first input / output port is used as the light input port. Therefore, Figure 12 As shown, the waveguide layer 15 is etched to form a third groove 1d on both the light-emitting surface 1c1 side of the first input / output port and the light-emitting surface 1c1 side of the second input / output port, and the third groove 1d on both light-emitting surface sides 1c1 is also connected to the first groove 1a and the second groove 1b. Furthermore, the areas where the first input / output port and the second input / output port output optical signals are both light-emitting areas, that is, Figure 13 As shown, the active layer 14 needs to be etched in both light-emitting regions to prevent the metal drop of the active layer 14 from affecting the ridge waveguide light emission. The etching length of the active layer 14 in the two light-emitting regions can be consistent or inconsistent. Figure 14 As shown, the top electrode 16 also needs to be etched in both light-emitting regions to prevent the metal of the top electrode 16 from falling and affecting the light emission of the ridge waveguide 1c. The etching length of the top electrode 16 in the two light-emitting regions can be consistent or inconsistent. Figure 11 As shown, the end faces of the first groove 1a on both light-exiting sides form an angle θ1 with the optical signal transmission direction, and the specific value of θ1 at the first input / output port and the second input / output port can be consistent or inconsistent. The end faces of the second groove 1b on both light-exiting sides also form an angle θ2 with the optical signal transmission direction, and the specific value of θ2 at the first input / output port and the second input / output port can be consistent or inconsistent. In summary, the optical gain chip 1 of Example 2 has a similar structure to the optical gain chip 1 of Example 1 and will not be further described here.

[0077] Example 3

[0078] like Figure 15 As shown, this embodiment provides an optical gain device, including: a cavity 2 and an optical gain chip 1 , wherein the optical gain chip 1 is disposed in the cavity 2 .

[0079] Specifically, in this embodiment, the optical gain chip 1 is processed in the cavity 2, the substrate 11 is located on the bottom side of the cavity 2, the electrode layer 16 is located on the top side of the cavity 2, and the waveguide layer 15 emits the optical signal to the side of the cavity 2. The side of the cavity 2 is coated with a reflective coating, and the optical signal is reflected by the side of the cavity 2 for use by other optical devices. As an example, Figure 15As shown, the cavity 2 is a rectangular cavity formed by cleavage. In practical applications, the specific method and shape of the cavity 2 are set according to needs, and are not limited to this embodiment.

[0080] Example 4

[0081] like Figure 16 As shown, this embodiment provides a method for manufacturing an optical gain chip 1, comprising the following steps:

[0082] like Figure 16 As shown, in step S1 , a bottom electrode 11 is provided, and a substrate 12 is formed on the bottom electrode 11 .

[0083] Specifically, in this embodiment, the bottom electrode 11 provides an electrical channel entrance for the optical gain chip 1, and the substrate 12 provides a base for subsequent grown layers. In practical applications, the specific material of the substrate 12 is selected as needed and will not be described in detail here.

[0084] like Figure 16 As shown, in step S2, a stacked confinement layer 13, an active layer 14 and a waveguide layer 15 are sequentially formed on a substrate 12; the thickness of the waveguide layer 15 varies monotonically along the propagation direction of the optical signal.

[0085] Specifically, in this embodiment, the thickness of the waveguide layer 15 is monotonically increasing or monotonically decreasing, in order to form the inclined ridge waveguide 1c. In addition, the active layer 14 is used to generate optical signals, the limiting layer 13 is used to limit the light field distribution of the active layer 14, and the waveguide layer 15 is used to guide the light field of the active layer 14 to be output outward. In actual applications, the specific materials of the limiting layer 13, the active layer 14, and the waveguide layer 15 are selected according to needs and will not be repeated here.

[0086] Specifically, in this embodiment, after the active layer 14 is formed and before the waveguide layer 15 is formed, in order to prevent the active layer 14 from affecting the light output of the ridge waveguide 1c, the active layer 14 in the light output region is etched so that the waveguide layer 15 is partially disposed on the upper surface of the confinement layer 13; wherein the etching length (etching size) of the active layer 14 in the direction of optical signal transmission is 10 μm-30 μm, including but not limited to 12 μm, 14 μm, 15 μm, 16 μm, 18 μm, 20 μm, 22 μm, 24 μm, 25 μm, 26 μm, and 28 μm, and the etching direction is perpendicular to the bottom surface of the substrate 11 at a vertical angle of 90°±2°. The etching can be performed by wet etching. In actual applications, the specific method of etching the active layer 14 is selected as needed and is not limited to this embodiment.

[0087] like Figure 16As shown, in step S3, the waveguide layer 15 is partially etched to obtain a first trench 1a and a second trench 1b with reduced thickness, a ridge waveguide 1c is formed between the first trench 1a and the second trench 1b, one end of the ridge waveguide 1c is etched to form a light emitting surface, and the waveguide layer 15 on the side of the light emitting surface 1c1 is partially etched to obtain a third trench 1d with reduced thickness.

[0088] Specifically, in this embodiment, the waveguide layer 15 is partially etched to form two grooves with reduced thickness. The area between the two grooves is called a ridge waveguide 1c. The etching morphology of the ridge waveguide 1c is substantially perpendicular to the first groove 1a and the second groove 1b, with a vertical angle of 90°±2°. The thickness of the two grooves after etching is set according to the required thickness of the ridge waveguide 1c, and the etching can be performed by dry etching or wet etching. Furthermore, one end of the ridge waveguide 1c is etched to form a light-emitting surface, and the waveguide layer 15 on one side of the light-emitting surface 1c1 is partially etched again to form a third groove 1d. The light-emitting surface having the third groove 1d after partial etching is the light outlet of the ridge waveguide 1c, wherein the etching length (etching size) of the third groove 1d in the optical signal transmission direction is 5-50μm, including but not limited to 6μm, 7μm, 8μm, 9μm, 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, and 45μm. Furthermore, the end surface of the first groove 1a on the light-emitting side is etched so that the end surface of the first groove 1a on the light-emitting side forms an angle θ1 with the optical signal propagation direction, and the range of angle θ1 is greater than 0 degrees and less than 90 degrees, including but not limited to 10 degrees, 20 degrees, 30 degrees, 40 degrees, 50 degrees, 60 degrees, 70 degrees, and 80 degrees. Furthermore, the end surface of the second groove 1b on the light-emitting side is etched so that the end surface of the second groove 1b on the light-emitting side forms an angle θ2 with the optical signal propagation direction, and the range of angle θ2 is greater than 0 degrees and less than 90 degrees, including but not limited to 10 degrees, 20 degrees, 30 degrees, 40 degrees, 50 degrees, 60 degrees, 70 degrees, and 80 degrees. The angle between the first groove 1a and the optical signal propagation direction may be equal to or different from the angle between the second groove 1b and the optical signal propagation direction.

[0089] like Figure 16 As shown, in step S4 , a top electrode 16 is formed on the waveguide layer 15 .

[0090] Specifically, in this embodiment, the top electrode 16 is formed on the waveguide layer 15, and provides an electrical signal input channel for the optical gain chip 1, and all layers between the bottom electrode 11 and the top electrode 16 are made of conductive materials. Furthermore, after the top electrode 16 is formed, in order to prevent the top electrode 16 from affecting the light emission of the ridge waveguide 1c, the top electrode 16 in the light emission area is etched, wherein the etching length (etching size) of the top electrode 16 in the direction of optical signal transmission is 10μm-30μm, including but not limited to 12μm, 14μm, 15μm, 16μm, 18μm, 20μm, 22μm, 24μm, 25μm, 26μm, 28μm, and the etching direction is perpendicular to the bottom surface of the substrate, and the vertical angle is 90°±2°. Etching can be performed by photolithography. As an example, Figure 7 As shown, the electrode layer 16 in the light-emitting region is etched into a trapezoidal shape. Along the direction of optical signal transmission, the length of the side of the trapezoid increases, i.e., the side of the trapezoid closer to the light-emitting region is longer than the side of the trapezoid farther from the light-emitting region. In practical applications, the specific method of etching the electrode layer 16 is selected as needed and is not limited to this embodiment.

[0091] It should be noted that the method for manufacturing the optical gain chip of this embodiment can be used to manufacture the optical gain chips of Embodiments 1 to 2, and can also be used to manufacture other optical gain chips, and is not limited to this embodiment.

[0092] In summary, the optical gain chip, device, and manufacturing method of the present invention comprise a bottom electrode, substrate, confinement layer, active layer, waveguide layer, and top electrode stacked in sequence. The waveguide layer is partially etched to form a ridge waveguide. The ridge waveguide is not only configured as an inclined ridge waveguide, but also has a light-emitting surface enclosed by first, second, and third grooves. This allows the optical signal emitted from the ridge waveguide to be reflected as far away from the ridge waveguide as possible, thus preventing secondary coupling. Furthermore, the present invention offers the advantages of excellent performance and a simple structure. Therefore, the present invention effectively overcomes the shortcomings of the prior art and possesses high industrial value.

[0093] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. An optical gain chip, characterized in that: The optical gain chip at least comprises: a bottom electrode, a substrate, a confinement layer, an active layer, a waveguide layer and a top electrode; The substrate is disposed on the bottom electrode, and the substrate serves as a base of the optical gain chip; The restriction layer is provided on the substrate and is used to restrict the optical signal generated by the active layer from entering the substrate; The active layer is provided on the confinement layer and is used to generate an optical signal; The waveguide layer is provided on the active layer, and is used to receive the optical signal of the active layer and output the optical signal; the waveguide layer is partially etched to form a first groove and a second groove; a ridge waveguide is formed between the first groove and the second groove, and the ridge waveguide guides the transmission of the optical signal generated by the active layer, and the thickness of the ridge waveguide changes monotonically along the transmission direction of the optical signal; one end of the ridge waveguide is a light-emitting surface, and the waveguide layer on one side of the light-emitting surface is partially etched to form a third groove, and the light-emitting surface having the third groove after being partially etched is a light outlet of the ridge waveguide; The top electrode is disposed on the waveguide layer.

2. The optical gain chip according to claim 1, wherein: The first groove, the second groove, and the third groove are communicated with each other.

3. The optical gain chip according to claim 1, wherein: The area where the light outlet outputs the optical signal is the light exit area. After the active layer in the light exit area is etched, the waveguide layer is partially arranged on the upper surface of the confinement layer.

4. The optical gain chip according to claim 3, wherein: The etching length of the active layer in the optical signal transmission direction is 10 μm-30 μm.

5. The optical gain chip according to claim 1, wherein: The area where the light outlet outputs the optical signal is the light exit area. After the top electrode in the light exit area is etched, the upper surface of the waveguide layer is partially exposed.

6. The optical gain chip according to claim 5, wherein: The etching length of the top electrode in the optical signal transmission direction is 10 μm-30 μm.

7. The optical gain chip according to claim 5, wherein: The etching shape of the top electrode in the light-emitting region is a trapezoid; the side length of the trapezoid close to the light-emitting side is greater than the side length away from the light-emitting side.

8. The optical gain chip according to claim 1, wherein: The angle between the end face of the first groove located on the light-emitting side and the propagation direction of the optical signal is 0 degrees to 90 degrees.

9. The optical gain chip according to claim 1, wherein: The angle between the end face of the second groove located on the light-emitting side and the propagation direction of the optical signal is 0 degrees to 90 degrees.

10. The optical gain chip according to claim 1, wherein: The two ends of the ridge waveguide are respectively provided with a first input / output port and a second input / output port, and the light output port is any one of the first input / output port or the second input / output port.

11. An optical gain device, characterized in that: The optical gain device comprises: a cavity and the optical gain chip according to any one of claims 1 to 10; the optical gain chip is arranged in the cavity.

12. A method for manufacturing an optical gain chip, characterized in that: The method for manufacturing the optical gain chip comprises at least the following steps: S1: providing a bottom electrode, on which a substrate is formed; S2: forming a stacked confinement layer, an active layer, and a waveguide layer in sequence on the substrate; the thickness of the waveguide layer changes monotonically along the direction of the optical signal; S3: Partially etching the waveguide layer to obtain a first groove and a second groove with reduced thickness; forming a ridge waveguide between the first groove and the second groove, etching one end of the ridge waveguide to form a light emitting surface, and partially etching the waveguide layer on one side of the light emitting surface to obtain a third groove with reduced thickness; S4: forming a top electrode on the waveguide layer.

13. The method for manufacturing an optical gain chip according to claim 12, wherein: In step S2, before the waveguide layer is formed, the active layer in the light exit area is etched so that the waveguide layer is partially disposed on the upper surface of the confinement layer.

14. The method for manufacturing an optical gain chip according to claim 12, wherein: In step S4, after the top electrode is formed, the top electrode in the light exiting region is etched so that the upper surface of the waveguide layer is partially exposed.

15. The method for manufacturing an optical gain chip according to claim 12, wherein: In step S3, the end face of the first groove on the light-emitting side is etched so that the end face of the first groove on the light-emitting side forms an angle with the propagation direction of the optical signal; the end face of the second groove on the light-emitting side is etched so that the end face of the second groove on the light-emitting side forms an angle with the propagation direction of the optical signal.

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