Semiconductor laser integrated structure and optical module

Abstract

The embodiment of the invention provides a semiconductor laser integrated structure and an optical module. The semiconductor laser integrated structure comprises a first electrode; a substrate; the semiconductor layer is arranged on the substrate, the semiconductor layer comprises an edge-emitting laser area, a waveguide structure and a photoelectric detector area, the waveguide structure comprises a first waveguide area, and the photoelectric detector area is located on the side, away from the backlight face, of the light-emitting face of the edge-emitting laser area and is coupled with a light-emitting light path of the edge-emitting laser area through the first waveguide area; the second electrode is connected with the upper waveguide layer of the edge emitting laser area; and the third electrode is connected with the second semiconductor layer of the photoelectric detector area. The semiconductor laser integrated structure provided by the embodiment of the invention has the characteristics of high integration level, higher monitoring efficiency and larger overall output optical power.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to an integrated structure and optical module for a semiconductor laser. Background Technology

[0002] Side-emitting lasers, such as DFB (Distributed Feedback Laser), are widely used in optical communication due to their high output power and fast transmission rate. When it is necessary to ensure stable optical output from the laser, a photodetector is needed to convert the optical signal into an electrical signal to monitor changes in the laser's output power. Current technologies require an additional detector chip, which is detrimental to product miniaturization. Summary of the Invention

[0003] Therefore, in order to overcome at least some of the defects in the prior art, the present invention provides a semiconductor laser integrated structure and optical module, which has the characteristics of high integration, higher monitoring efficiency, and larger overall output optical power.

[0004] An embodiment of the present invention provides an integrated semiconductor laser structure, comprising: a first electrode; a substrate disposed on the first electrode; a semiconductor layer disposed on the substrate, the semiconductor layer comprising a side-emitting laser region and a photodetector region sequentially disposed along its length, the side-emitting laser region comprising a lower waveguide layer, an active layer, and an upper waveguide layer sequentially disposed on the substrate along the thickness direction of the semiconductor layer; the side-emitting laser region having a backlight surface and a light-emitting surface opposite each other along its length; the photodetector region being located on the side of the light-emitting surface of the side-emitting laser region away from the backlight surface; the photodetector region comprising a first semiconductor layer, a light-absorbing layer, and a second semiconductor layer sequentially disposed on the substrate along the thickness direction; the semiconductor layer further comprising a waveguide structure, the waveguide structure comprising a first waveguide region disposed between the side-emitting laser region and the photodetector region, the photodetector region being coupled to the light-emitting optical path of the side-emitting laser region through the first waveguide region; a second electrode connected to the upper waveguide layer; and a third electrode connected to the second semiconductor layer.

[0005] This invention also provides an optical module, including the aforementioned semiconductor laser integrated structure.

[0006] The above embodiments of the present invention have at least one or more of the following beneficial effects: the photodetector region and the side-emitting laser region are integrated together by sharing a substrate and a first electrode, eliminating the need for separate packaging of the detector and laser, thus saving space, reducing costs, and improving structural reliability. Furthermore, the laser can be directly coupled to the photodetector region, resulting in higher monitoring efficiency and more precise alignment, which is beneficial for device miniaturization. In addition, by placing the photodetector region on the light-emitting side of the side-emitting laser region, the overall output optical power of the semiconductor laser integrated structure can be maintained at a high level while monitoring the optical output power of the side-emitting laser region through the photodetector. Attached Figure Description

[0007] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings. The drawings are only used to illustrate the spatial relationship of the various structural parts and do not represent the actual thickness, size, or relative proportion of the various structural parts.

[0008] Figure 1 This is a schematic diagram of the elevation cross-section of a semiconductor laser integrated structure provided in one embodiment of the present invention.

[0009] Figure 2 A cross-sectional view of a semiconductor laser integrated structure provided in another embodiment of the present invention.

[0010] Figure 3 For the corresponding Figure 2 The integrated semiconductor laser structure shown does not display a three-dimensional schematic diagram of the first, second, and third electrodes.

[0011] Figure 4 for Figure 1 The integrated semiconductor laser structure shown does not display a three-dimensional schematic diagram of the first, second, and third electrodes.

[0012] Figure 5 for Figure 4 The structure shown corresponds to Figure 1 A cross-sectional view of the structure.

[0013] Figure 6 for Figure 2 The diagram shows a top view of the integrated semiconductor laser structure.

[0014] Figure 7 for Figure 4 The diagram shows a top view of the structure.

[0015] Figure 8 This is a three-dimensional structural diagram of the substrate and semiconductor layer in another embodiment of a semiconductor laser integrated structure.

[0016] Figure 9 for Figure 8A cross-sectional structural diagram of the structure shown.

[0017] Figure 10 This is a cross-sectional view of a semiconductor laser integrated structure provided in another embodiment of the present invention.

[0018] [Explanation of Labels in the Attached Image] 100. Integrated structure of semiconductor laser; 10. First electrode; 20. Substrate; 30. Semiconductor layer; 31. Side-emitting laser region; 311. Lower waveguide layer; 312. Active layer; 313. Upper waveguide layer; 314. Grating layer; 315. Backlight surface; 316. Light-emitting surface; 32. Photodetector region; 321. First semiconductor layer; 322. Light absorption layer; 323. Second semiconductor layer; 33. Waveguide structure; 331. First waveguide region; 332. Second waveguide region; 40. Second electrode; 50. Third electrode; 60. High-reflection structure; 70. Anti-reflection coating. Detailed Implementation

[0019] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0020] To enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0021] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0022] It should also be noted that the division of multiple embodiments in this invention is only for the convenience of description and should not constitute a special limitation. Features in various embodiments can be combined and referenced in each other without contradiction.

[0023] Reference Figure 1 or Figure 2 and Figure 6 One embodiment of the present invention provides a semiconductor laser integrated structure 100, including: a first electrode 10, a substrate 20, a semiconductor layer 30, a second electrode 40, and a third electrode 50. The substrate 20 is disposed on the first electrode 10. The semiconductor layer 30 is disposed on the substrate 20. Figures 1 to 9 In the diagram, the X direction represents the length of semiconductor layer 30, the Y direction represents the width of semiconductor layer 30, and the Z direction represents the thickness of semiconductor layer 30. For ease of illustration of the layer structure, Figure 3 and Figure 4 The first electrode 10, the second electrode 40, and the third electrode 50 were removed. Figure 5 and Figure 9 perspective and Figure 1 They share the same perspective.

[0024] The semiconductor layer 30 includes a side-emitting laser region 31 and a photodetector region 32 arranged sequentially along its length, as shown in the figure. Figure 4 and Figure 5 The edge-emitting laser region 31 includes a lower waveguide layer 311, an active layer 312, and an upper waveguide layer 313 sequentially disposed on the substrate along the thickness direction of the semiconductor layer 30. The edge-emitting laser region 31 has a backlight surface 315 and a light-emitting surface 316 opposite each other along its length. (Refer to...) Figure 5 The photodetector region 32 includes a first semiconductor layer 321, a light-absorbing layer 322, and a second semiconductor layer 323 sequentially disposed on the substrate 20 along the thickness direction. The semiconductor layer 30 also includes a waveguide structure 33, which includes a first waveguide region 331 disposed between the side-emitting laser region 31 and the photodetector region 32. The photodetector region 32 is coupled to the light output path of the side-emitting laser region 31 through the first waveguide region 331. The second electrode 40 is connected to the upper waveguide layer 313. The third electrode 50 is connected to the second semiconductor layer 323.

[0025] In some embodiments, the length, width and thickness of the light absorption layer 322 are configured to satisfy the light absorption rate of the light emitted from the laser region opposite to the edge of the light absorption layer 322 (referred to as the light absorption rate of the light absorption layer 322) as 1% to 5%.

[0026] In some embodiments, refer to Figure 2 and Figure 3The semiconductor laser integrated structure 100 also includes a high-reflectivity structure 60, which is disposed on the side of the edge-emitting laser region 31 away from the photodetector region 32, that is, on the back surface 315 of the edge-emitting laser region 31. In some embodiments, the semiconductor laser integrated structure 100 also includes an anti-reflection film 70, which covers the end face of the photodetector region 32 on the side away from the edge-emitting laser region 31.

[0027] Specifically, the first electrode 10 is an N-type electrode, also known as a negative electrode. For example, it can be an AuGe / Ni / Au stacked structure. The substrate 20 is an N-type substrate, specifically an N-type InP substrate. The edge-emitting laser region 31 and the photodetector region 32 share the substrate 20 and the first electrode 10.

[0028] In the side-emitting laser region 31, the lower waveguide layer 311, also known as the N-type waveguide layer, can be made of InGaAsP or AlGaInP, doped with Si atoms. The active layer 312 is a quantum well structure, which can be an alternating InGaAsP / InGaAs structure. The thickness e3 of the active layer 312 (refer to...) Figure 5 The thickness is 0.05~0.15μm. The upper waveguide layer 313 can also be called a P-type waveguide layer, and the material can be InGaAsP or AlGaInP, doped with Zn atoms. In some embodiments, the side-emitting laser region 31 further includes a grating layer 314, which is disposed between the active layer 312 and the upper waveguide layer 313. The grating layer 314 can adopt an InGaAsP / InP lateral periodic structure. The second electrode 40 is the P-electrode corresponding to the side-emitting laser region 31, and can also be called the positive electrode of the side-emitting laser region 31. The second electrode 40 can be, for example, a Ti / Pt / Au stacked structure. The first electrode 10, substrate 20, lower waveguide layer 311, active layer 312, grating layer 314, upper waveguide layer 313 and second electrode 40 can together form a DFB laser structure.

[0029] Its working principle is as follows: Under positive voltage drive, current is injected through the first electrode 10 and the second electrode 40. Holes start from the second electrode 40 and move through the upper waveguide layer 313 to the active layer 312. At the same time, electrons start from the first electrode 10 and move through the substrate 20 and the lower waveguide layer 311 to the active layer 312. Charge carriers (holes and electrons) are injected into the active layer 312 to generate optical gain, and a stable single-mode lasing is formed by the grating layer 314. Combined with the effects of the high-reflection structure 60 and the anti-reflection film 70, laser light is mainly emitted from the light-emitting surface 316, of which a small portion of the laser light is emitted from the back light surface 315.

[0030] Of course, in some other embodiments, the side-emitting laser region 31 can also form an FP (Fabry-Perot) laser together with the first electrode 10, the substrate 20 and the second electrode 40, in which case the side-emitting laser region 31 is not provided with a grating layer 314.

[0031] In the photodetector region 32, the first semiconductor layer 321 is an N-type semiconductor layer, which can be made of InP and doped with Si atoms. The light absorption layer 322 can be made of InGaAs. The second semiconductor layer 323 is a P-type semiconductor layer, which can be made of InP or InGaAs and doped with Zn atoms. The third electrode 50 is the P-electrode corresponding to the photodetector region 32, and can also be called the negative electrode corresponding to the photodetector region 32. The material of the third electrode 50 can be the same as that of the second electrode 40. The first electrode 10, the substrate 20, the first semiconductor layer 321, the light absorption layer 322, the second semiconductor layer 323, and the third electrode 50 together constitute a photodiode structure. The laser emitted from the side-emitting laser region 31 is injected into the light absorption layer 322 to form photogenerated carriers. When a negative voltage (i.e., reverse bias) relative to the first electrode 10 is applied to the third electrode 50, a photocurrent can be generated. The magnitude of the generated photocurrent can be used to monitor the optical power of the laser generated by the side-emitting laser region 31.

[0032] The high-reflectivity structure 60 can be a DBR (Distributed Bragg Reflector) mirror structure or a high-reflectivity coating, specifically such as a SiO / SiN alternating structure or a metal reflective film, which can provide a reflectivity of over 99%. This reflects the light emitted from the edge-emitting laser region 31 from the backlight surface 315, thereby increasing the light output power. The high-reflectivity structure 60 also protects the backlight surface 315 from oxidation, improving device reliability. The anti-reflection coating 70 can be a SiO / SiN alternating structure, and its reflectivity for light emitted from the edge-emitting laser region 31 is less than or equal to 10%. By setting the anti-reflection coating 70, the light extraction performance can be further improved, and the end face of the photodetector region 32 can be protected from oxidation.

[0033] It should be noted that the semiconductor laser integrated structure 100 also includes necessary structures such as insulating layers and dielectric layers. Other layers in the side-emitting laser region 31 can be set with reference to the layer structure of a traditional side-emitting laser, and other layers in the photodetector region 32 can be set with reference to the layer structure of a traditional photodiode. Examples will not be given here.

[0034] Based on the principle of edge-emitting lasers, during laser oscillation, light waves reflect back and forth between the two cleaved surfaces of the waveguide. One surface serves as the main output surface, coupled into the optical fiber, while the other surface "leaks" a portion of the light. This structure naturally provides a physically separate but optically related optical path for monitoring. Since the light output from the front accounts for a larger proportion, approximately 99%, while the proportion emitted from the back is smaller, approximately 1%, in related schemes, a photodiode chip can be placed on the back of the edge-emitting laser to absorb the "leaked" 1% of light, thereby enabling monitoring of the optical power of the laser generated by the edge-emitting laser without affecting its normal output. In this structure, to ensure sufficient light absorption to meet the photoelectric conversion requirements, the photodiode chip has an absorption rate of approximately 90% for the laser emitted from the back of the edge-emitting laser. This is a discrete device, which presents a problem of large size.

[0035] In the semiconductor laser integrated structure 100 provided in this embodiment, the photodetector region 32 is located on the side of the light-emitting surface 316 of the side-emitting laser region 31 away from the backlight surface 315 (i.e., the light-emitting side). First, the photodetector region 32 and the side-emitting laser region 31 share the substrate 20 and the first electrode 10 and are integrated together. There is no need to separately package the detector and the laser, which can save space, reduce costs, improve the reliability of the structure, and can directly couple the laser to the photodetector region 32, resulting in higher monitoring efficiency, more accurate alignment, and is conducive to the miniaturization of the device.

[0036] Specifically, in some examples, the photodetector region 32 is positioned between the high-reflectivity structure 60 and the side-emitting laser region 31, while the side-emitting laser region 31 is integrated with the photodetector region 32. The light extraction process is as follows: the side-emitting laser region 31 generates optical gain → the photodetector region 32 absorbs the light → the high-reflectivity structure 60 reflects the light → the photodetector region 32 absorbs the light a second time → the side-emitting laser region 31 gains the light a second time → the antireflection coating 70 emits the light. In this light extraction process, the laser is absorbed twice by the photodetector region 32, resulting in lower light extraction performance. Furthermore, since the light reflected from the high-reflectivity structure 60 back to the side-emitting laser region 31 passes through the photodetector region 32, it is equivalent to passing through an additional cavity. The light from this additional cavity, combined with the light from the side-emitting laser region 31 itself, causes interference and a feedback effect. This feedback effect leads to severe fluctuations in the output power-current curve of the side-emitting laser region 31, affecting the normal operation of the laser device. In this embodiment, the photodetector region 32 is positioned on the light-emitting side of the side-emitting laser region 31, and the light absorption rate of the light absorption layer is controlled. The light emission process of the light generated by the side-emitting laser region 31 is as follows: the side-emitting laser region 31 generates light gain → the high-reflection structure 60 reflects the light → the side-emitting laser region 31 gains a second gain → the photodetector region 32 absorbs the light → the antireflection film 70 emits the light. During this emission process, the laser is absorbed only once by the photodetector region 32, ensuring high-efficiency light emission performance. Furthermore, the laser entering the photodetector region 32 ultimately passes directly through the antireflection film 70 for emission, preventing feedback effects and ensuring a smooth output power-current curve for the side-emitting laser region.

[0037] In some embodiments, the light absorption rate η of the light absorption layer 322 can be calculated according to formula (1): Formula (1): Where α is the absorption coefficient of the light-absorbing layer 322, Γ1 is the light-confining factor of the light-absorbing layer 322, and L1 is the length of the light-absorbing layer 322. The light-confining factor Γ1 of the light-absorbing layer 322 can be calculated according to formula (2): Formula (2): Where W1 is the width of the light absorption layer 322, e1 is the thickness of the light absorption layer 322, and Sp is the equivalent cross-sectional area of ​​the emitted light field of the edge-emitting laser region 31 at the absorption surface of the light absorption layer 322. In this embodiment, the absorption surface of the light absorption layer 322 is the plane to which the first interface between the photodetector region 32 and the first waveguide region belongs. For example, the length L2 of the first waveguide region 331 (refer to...) Figure 7 When the value is 1~5 micrometers, the change in Sp can be ignored. At this time, Sp can be approximately calculated according to formula (3). Formula (3): Where W3 is the ridge width of the side-emitting laser region 31 (refer to...) Figure 3 or Figure 4In some embodiments, W3 ranges from 3 to 20 μm, and e3 is the thickness of the active layer 312 (refer to...). Figure 5 The size of the light absorption layer 322 can be adjusted according to formulas (1) to (3) above to adjust the light absorption rate of the light absorption layer 322 to 1%~5%. (Refer to...) Figure 5 The thickness e1 of the light-absorbing layer 322 is its dimension along the thickness direction of the semiconductor layer 30. The length L1 of the light-absorbing layer 322 is its dimension along the length direction of the semiconductor layer 30. The width W1 of the light-absorbing layer 322 is its dimension along the width direction of the semiconductor layer 30, which can be referred to... Figure 3 , Figure 4 , Figure 7 .

[0038] Specifically, in some embodiments, aligning the center of the light-absorbing layer 322 with the center of the active layer 312 ensures high optical coupling efficiency and facilitates the determination of the dimensions of the light-absorbing layer 322. Due to process variations, an error within 0.02 μm in the thickness direction and an error within 0.2 μm in the width direction can be considered. That is, refer to... Figure 5 In the thickness direction of semiconductor layer 30, the distance between the center line CL2 of light-absorbing layer 322 and the center line CL1 of active layer 312 is less than or equal to 0.02 micrometers. (Refer to...) Figure 7 In the width direction of semiconductor layer 30, the distance between the center line CL4 of light absorption layer 322 and the center line CL3 of active layer 312 is less than or equal to 0.2 micrometers.

[0039] In some embodiments, the length L1 of the light absorption layer 322 ranges from 0.5 to 2 micrometers, specifically for example, 0.5 μm, 1 μm, 1.5 μm, 2 μm, etc. According to the above formula (1), when the light confinement factor Γ1 and the material absorption coefficient α of the light absorption layer 322 are determined, the light absorption efficiency η is proportional to the length L1 of the light absorption layer 322. In this application, the light absorption rate of the photodetector region 32 can be adjusted by controlling the length L1 of the light absorption layer. While satisfying the requirement of a small light absorption rate, the length L1 of the light absorption layer can also be set to be small, so that the overall length of the semiconductor laser integrated structure 100 is smaller, which is more conducive to the miniaturization of the product.

[0040] As illustrated above, the material of the light absorption layer 322 is InGaAs. Within a certain wavelength range, the absorption coefficient changes inversely with the wavelength. For example, when the output laser wavelength is 1550 nm, α is 6000 cm⁻¹. -1 When the wavelength of the output laser is 1310nm, α is 10000cm. -1In this embodiment, the light confinement factor Γ1 of the light absorption layer 322 is 1.5%~2.5%, specifically, for example, 1.5%, 2%, 2.5%, etc. Preferably, L1=1μm, Γ1=2%. For example, when the corresponding α is 6000cm -1 When L1 = 1 micrometer and Γ1 = 2%, then η equals 1.2%.

[0041] Furthermore, in some embodiments, the width W1 of the light absorption layer 322 is 0.5~4 micrometers, specifically, for example, 0.5μm, 1μm, 1.5μm, 2μm, 3μm, 4μm, etc. The thickness e1 of the light absorption layer 322 is 0.05~2 micrometers, specifically, for example, 0.05μm, 0.08μm, 0.1μm, 0.2μm, 0.4μm, 1μm, 2μm, etc. In the formation process of the photodetector region 32, an epitaxial growth combined with an etching process is used to process the light absorption layer 322 to the required size. Therefore, in this embodiment, the width W1 of the light absorption layer 322 is set to be relatively large, while the thickness e1 is set to be relatively small, which can reduce the difficulty of the process. In one embodiment, W1=1μm, e1=1μm, which makes Γ1 approximately 2%.

[0042] In some embodiments, the waveguide structure 33 can be an undoped layer or an ion-implanted layer. When the waveguide structure 33 is an undoped layer, its material can be InGaAsP or InP. When the waveguide structure 33 is an ion-implanted layer, the host material of the waveguide structure 33 can be the same as the host material of the first semiconductor layer 321. For example, the host material of the first semiconductor layer 321 is InP, and the waveguide structure 33 is hydrogen ion-implanted InP. When the host material of the waveguide structure 33 is the same as the host material of the first semiconductor layer 321, the waveguide structure 33 and the photodetector region 32 can be epitaxially grown simultaneously, which can save process steps and reduce process difficulty. In some embodiments, refer to Figure 8 and Figure 9 The first waveguide region 331 and the light absorption layer 322 are jointly disposed on the first semiconductor layer 321. In some embodiments, reference is made to... Figure 10 The main materials of the first semiconductor layer 321, the first waveguide region 331 and the lower waveguide layer 311 can be the same. For example, if the main materials are all InP materials, they can be epitaxially grown simultaneously, which can save process steps.

[0043] In some embodiments, the waveguide structure 33 further includes second waveguide regions 332 disposed on opposite sides of the photodetector region 32 along the width direction of the semiconductor layer 30. The second waveguide region 332 is made of the same material as the first waveguide region 331. In some embodiments, there is no actual boundary between the first waveguide region 331 and the second waveguide region 332. In this embodiment, the portion of the waveguide structure 33 located between the side-emitting laser region 31 and the photodetector region 32 is referred to as the first waveguide region 331, and the remaining portion is referred to as the second waveguide region 332.

[0044] In some embodiments, the width W1 of the photodetector region 32 is smaller than the width W2 of the first waveguide region 331. The sum of the width W1 of the photodetector region 32 and the widths of the second waveguide regions 332 on both sides is greater than or equal to the width W1 of the first waveguide region 331. The antireflective coating 70 also covers the end face of the second waveguide region 332 away from the first waveguide region 331. (Refer to...) Figure 3 or Figure 4 The widths of the second waveguide regions 332 on both sides are W4 and W5 respectively (W4 and W5 are equal in some embodiments), that is, W1+W4+W5≥W2. When the length L1 of the photodetector region 32 is set to be small, the spot size of the laser emitted by the side-emitting laser region 31 at the first interface is basically the same as the spot size on the end face of the photodetector region 32 away from the first waveguide region 331. At this time, W1+W4+W5=W2 can be set.

[0045] By providing the second waveguide region 332, the side surface of the photodetector region 32 along the width direction of the semiconductor layer 30 can be protected from oxidation. Additionally, the second waveguide region 332 can guide the portion of light emitted from the side-emitting laser region 31 that has not been absorbed by the photodetector region 32, thus ensuring laser output power and reducing laser loss.

[0046] The width W2 of the first waveguide region 331 needs to be greater than the ridge width W3 of the side-emitting laser region 31 to ensure efficient extraction of the laser emitted from the side-emitting laser region 31. More specifically, the width W2 of the first waveguide region 331 needs to be greater than or equal to the spot width of the emitted light field of the side-emitting laser region 31 on the plane of the first interface, simply referred to as W2 being greater than or equal to the Sp width. In some embodiments, an equivalent circle with an area equal to Sp can be defined, and W2 can be approximately considered to be greater than or equal to the diameter of this effective circle. Therefore, it can be obtained that... According to the above formula (3), we can obtain Depending on the actual manufacturing cost and the typical size of semiconductor lasers, W2 is usually controlled to be less than or equal to 60 micrometers.

[0047] This invention also provides an optical module, which is any of the aforementioned semiconductor laser integrated structures 100. This optical module can be applied, for example, in data centers to achieve high-speed, low-latency interconnection between servers, switches, and storage devices. Alternatively, it can be used in LiDAR optical systems for autonomous vehicles.

[0048] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A semiconductor laser integrated structure, characterized in that, include: First electrode; A substrate is disposed on the first electrode; A semiconductor layer is disposed on the substrate. The semiconductor layer includes an edge-emitting laser region and a photodetector region sequentially disposed along its length. The edge-emitting laser region includes a lower waveguide layer, an active layer, and an upper waveguide layer sequentially disposed on the substrate along the thickness direction of the semiconductor layer. The edge-emitting laser region has a backlight surface and a light-emitting surface opposite each other along its length. The photodetector region is located on the side of the light-emitting surface of the edge-emitting laser region away from the backlight surface. The photodetector region includes a first semiconductor layer, a light-absorbing layer, and a second semiconductor layer sequentially disposed on the substrate along the thickness direction. The semiconductor layer also includes a waveguide structure, which includes a first waveguide region disposed between the edge-emitting laser region and the photodetector region. The photodetector region is coupled to the light-emitting optical path of the edge-emitting laser region through the first waveguide region. The second electrode is connected to the upper waveguide layer; The third electrode is connected to the second semiconductor layer.

2. The semiconductor laser integrated structure as described in claim 1, characterized in that, The length, width, and thickness of the light-absorbing layer are configured to ensure that the light absorption rate of the light-absorbing layer for the light emitted from the edge-emitting laser region is 1% to 5%.

3. The semiconductor laser integrated structure as described in claim 2, characterized in that, In the thickness direction of the semiconductor layer, the distance between the center line of the light-absorbing layer and the center line of the active layer is less than or equal to 0.02 micrometers, and in the width direction of the semiconductor layer, the distance between the center line of the light-absorbing layer and the center line of the active layer is less than or equal to 0.2 micrometers.

4. The semiconductor laser integrated structure as described in claim 3, characterized in that, The length of the light-absorbing layer ranges from 0.5 to 2 micrometers.

5. The semiconductor laser integrated structure as described in claim 4, characterized in that, The width of the light-absorbing layer ranges from 0.5 to 4 micrometers, and the thickness ranges from 0.05 to 2 micrometers.

6. The semiconductor laser integrated structure as described in claim 1, characterized in that, The main material of the waveguide structure is the same as the main material of the first semiconductor layer, and the waveguide structure is either an ion-implanted layer or an undoped layer.

7. The semiconductor laser integrated structure as described in claim 1, characterized in that, The waveguide structure further includes a second waveguide region disposed on opposite sides of the photodetector region along the width direction of the semiconductor layer.

8. The semiconductor laser integrated structure as described in claim 7, characterized in that, It also includes an antireflection coating, which covers the end face of the photodetector region on the side away from the edge-emitting laser region.

9. The semiconductor laser integrated structure as described in claim 8, characterized in that, The width of the photodetector region is less than the width of the first waveguide region, and the sum of the width of the photodetector region and the widths of the second waveguide regions on both sides is greater than or equal to the width of the first waveguide region; the antireflection film also covers the end face of the second waveguide region away from the first waveguide region.

10. The semiconductor laser integrated structure as described in claim 1, characterized in that, The interface between the photodetector region and the first waveguide region is defined as the first interface, and the width of the first waveguide region is greater than or equal to the spot width of the emitted light field of the side-emitting laser region on the plane to which the first interface belongs.

11. The semiconductor laser integrated structure according to any one of claims 1 to 10, characterized in that, It also includes a highly reflective structure disposed on the back surface of the side-emitting laser area.

12. An optical module, characterized in that, The optical module includes the semiconductor laser integrated structure according to any one of claims 1 to 11.

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