A method for fabricating and structure of a photonic integrated device

Abstract

This invention discloses a method and structure for fabricating a photonic integrated device. The method includes: dividing a substrate sequentially into a pre-modulator region, a post-modulator region, a pre-grating region, a gain region, and a post-grating region; growing a first active layer after fabricating a selected-area epitaxial mask pattern in the gain region; growing a second active layer in the pre-modulator region after mask etching; growing a third active layer in the grating region after mask etching; finally, fabricating the grating; and completing the fabrication of the cladding, electrical contact layer, inverted shallow ridge waveguide structure, electrical isolation trench, and electrodes. This method achieves the integration of multiple materials through a single selected-area epitaxial growth and a single docking growth, saving material growth steps and reducing manufacturing costs. The gain region and post-modulator region achieve bandgap shift through selected-area epitaxial material growth, and the design of photofluorescence wavelength differences in each region enables multi-wavelength tuning and efficient modulation, providing a solution for the integration of wide-wavelength tunable lasers and dual-electric absorption modulators.

Description

Technical Field

[0001] This invention relates to the field of semiconductor optoelectronic integrated device technology, and in particular to a method for fabricating and structure of a photonic integrated device. Background Technology

[0002] With the explosive growth of the internet and the rapid development of artificial intelligence, the demand for high-performance photonic integrated devices in the optical communication field is increasing, especially the integration of wide-wavelength tunable lasers with electro-absorption modulators. These integrated devices can improve the flexibility and efficiency of signal transmission in high-speed optical communication systems, adapting to the ever-growing demand for high-capacity data transmission. Meanwhile, the development trend of photonic integration technology is towards smaller size, higher performance, and lower power consumption devices, which drives the exploration of innovative fabrication methods to achieve a high degree of integration of complex photonic functions.

[0003] Traditional methods for fabricating photonic integrated devices often employ multiple-stage docking growth techniques. While this technique can achieve a certain degree of device integration, it has significant drawbacks. On the one hand, the multiple growth processes are complex, making it difficult to guarantee docking accuracy and easily introducing interface defects, thus affecting the device's optoelectronic performance and reliability. On the other hand, frequent material growth and etching steps result in high manufacturing costs and low production efficiency, making it difficult to meet the demands of large-scale industrialization. Furthermore, existing technologies are insufficient in achieving precise material design and performance optimization for different functional regions such as the gain region, modulator region, and grating region, limiting the improvement of overall device performance.

[0004] Therefore, there is a need to provide a photonic integrated device and its fabrication method that can reduce the number of times the active layer is grown, reduce material growth costs and process complexity, thereby improving production efficiency. This provides an efficient and economical solution for the integration of wide-wavelength tunable lasers with single-ended double-electric absorption modulators, thus promoting the development of photonic integrated devices towards high performance and low cost. Summary of the Invention

[0005] In view of this, the present invention provides a method and structure for fabricating a photonic integrated device, which can solve the technical problems of difficulty in integrating a wide wavelength tunable range with an electroabsorption modulator, low device reliability, and high manufacturing cost in the prior art.

[0006] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a method for fabricating a photonic integrated device, comprising:

[0008] The substrate is laid out by dividing the substrate surface along the length direction into a front modulator region, a rear modulator region, a front grating region, a gain region, and a rear grating region.

[0009] A selected area epitaxial mask pattern is fabricated on the surface of the gain region of the substrate. The selected area epitaxial mask pattern consists of two parallel strips with the same length as the gain region and a preset spacing and width.

[0010] A first active layer is grown on the substrate surface in the area other than the selected area epitaxial mask pattern. Then the selected area epitaxial mask pattern is removed by etching. A first docking mask pattern is fabricated in the area other than the pre modulator region. The first active layer other than the first docking mask pattern is removed by etching.

[0011] A second active layer is grown on the surface of the pre-modulator region, and then the first docking mask pattern is removed by etching.

[0012] A second docking mask pattern is fabricated in the area outside the front grating region and the rear grating region, and the first active layer of the front grating region and the rear grating region is etched away.

[0013] A third active layer is grown in the front grating region and the rear grating region using docking growth technology. Then, the second docking mask pattern is removed, and sampling gratings are fabricated in the front grating region and the rear grating region.

[0014] A cladding layer and an electrical contact layer are sequentially grown on the surface of the entire device, and an inverted shallow ridge waveguide structure is fabricated on the cladding layer and the electrical contact layer.

[0015] Electrical isolation trenches are etched on the electrical contact layer to achieve electrical isolation between different areas;

[0016] P-side electrodes are fabricated on the electrical contact layers in each region. After the substrate is thinned, N-side electrodes are fabricated on the overall surface at the bottom of the substrate to complete the integrated device fabrication.

[0017] Furthermore, the photofluorescence wavelength of the third active layer in the front grating region and the rear grating region is 150–200 nm shorter than the photofluorescence wavelength of the first active layer in the gain region.

[0018] Furthermore, the photofluorescence wavelength of the second active layer in the pre-modulator region is 30-60 nm shorter than that of the first active layer in the post-modulator region.

[0019] Furthermore, the lengths of the front modulator region and the rear modulator region are both 150 micrometers, the length of the front grating region is 50 micrometers, the length of the gain region is 300 micrometers, and the length of the rear grating region is 250 micrometers. An electrical isolation region with a spacing of 50 micrometers is provided between adjacent regions.

[0020] Furthermore, the first active layer comprises, from bottom to top, a first lower waveguide layer, a first multiple quantum well layer, and a first upper waveguide layer; the thickness of the first lower waveguide layer and the first upper waveguide layer is 100 nm.

[0021] Furthermore, the first multi-quantum-well layer is formed by the interleaving growth of multiple quantum well layers and multiple barrier layers.

[0022] Furthermore, the second active layer comprises, from bottom to top, a second lower waveguide layer, a second multiple quantum well layer, and a second upper waveguide layer; the thickness of the second lower waveguide layer and the second upper waveguide layer is 80 nm, and the thickness of the second multiple quantum well layer is greater than the thickness of the first multiple quantum well layer.

[0023] Furthermore, the method for removing the first active layer of the front and rear grating regions employs ICP etching.

[0024] Furthermore, the width of the electrical isolation trench is 50 micrometers.

[0025] On the other hand, the present invention also provides a structure of a photonic integrated device, which is fabricated using the preparation method described in the above technical solution. The device comprises, from bottom to top, an N-side electrode, a substrate, an active layer, a cladding layer, an electrical contact layer, and a P-side electrode.

[0026] The device is divided into a front modulator region, a rear modulator region, a front grating region, a gain region, and a rear grating region, starting from one side and proceeding along its length.

[0027] The bandgap of the gain region and the post-modulator region is shifted by selective epitaxial growth of materials. The photofluorescence wavelength of the gain region is 150-200 nm longer than that of the grating region material, and the photofluorescence wavelength of the pre-modulator region material is 30-60 nm shorter than that of the post-modulator region material.

[0028] Compared to existing technologies, the advantages of this method are:

[0029] (1) Improve reliability: This method integrates the gain region material and two modulator materials through one selective epitaxial growth and one docking growth, integrating a wide-wavelength tunable laser with two electroabsorption modulators. Compared with the existing technology that requires two docking preparation techniques, this method saves one growth of the active layer, reduces the problem of docking interface defects caused by multiple docking epitaxial growths, and improves the reliability of the device.

[0030] (2) Reduced interface defects: In traditional technology, multiple epitaxial growths are prone to interface defects, which affect device performance. This method reduces the number of growth cycles by optimizing the process flow, thereby effectively reducing interface defects.

[0031] (3) Save manufacturing costs: This method achieves the integration of multiple materials through one selective epitaxial growth and one docking growth, avoiding the traditional multiple growth and complex process steps, reducing production costs, and improving production efficiency. It provides an economical and efficient solution for the integration of wide-wavelength tunable lasers and single-ended double-electric absorption modulators. Attached Figure Description

[0032] Figure 1 A schematic flowchart illustrating the fabrication method of the photonic integrated device provided by the present invention;

[0033] Figure 2 This is a schematic diagram of the substrate and region division provided by the present invention;

[0034] Figure 3 A top view of the structure for fabricating a selected area epitaxial mask pattern on a substrate surface, provided by the present invention;

[0035] Figure 4 A schematic diagram of the structure for fabricating the first docking mask and etching away the active material in the premodulator region, provided by the present invention;

[0036] Figure 5 A schematic diagram of the structure of the second active material in the modulator region before docking growth provided by the present invention;

[0037] Figure 6 A top view of the second docking mask pattern outside the grating region provided by the present invention;

[0038] Figure 7 A schematic diagram of the structure of the third active layer for obtaining the rear grating region and the front grating region using the docking growth technique provided by the present invention;

[0039] Figure 8 A schematic diagram of the structure after the growth cladding and electrical contact layer provided by the present invention;

[0040] Figure 9 A cross-sectional view of a fracturing shallow ridge waveguide structure fabricated on the cladding and electrical contact layers provided for this invention;

[0041] Figure 10 A side view of the device after it has been manufactured according to the present invention;

[0042] In the figure, 1-front modulator region, 2-rear modulator region, 3-front grating region, 4-gain region, 5-rear grating region, 10-substrate, 11-selective epitaxial mask pattern, 12-first lower waveguide layer, 13-first multiple quantum well layer, 14-first upper waveguide layer, 15-second lower waveguide layer, 16-second multiple quantum well layer, 17-second upper waveguide layer, 18-second docking mask pattern, 19-third active layer, 20-grating, 21-cladding, 22-electrical contact layer, 23-P-side electrode, 24-N-side electrode. Detailed Implementation

[0043] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0044] Example 1

[0045] Please see Figure 1 , Figure 1 This embodiment illustrates a flowchart of a method for fabricating a photonic integrated device, which includes:

[0046] Step S101: Perform surface layout on the substrate, dividing the substrate surface along the length direction into a front modulator region, a rear modulator region, a front grating region, a gain region, and a rear grating region.

[0047] Step S102: Create a selected area epitaxial mask pattern on the surface of the gain region of the substrate. The selected area epitaxial mask pattern consists of two parallel strips with the same length as the gain region and a preset spacing and width.

[0048] Step S103: Grow a first active layer on the substrate surface except for the selected area epitaxial mask pattern, then etch away the selected area epitaxial mask pattern, and fabricate a first docking mask pattern in the area except for the pre-modulator region, and etch away the first active layer except for the first docking mask pattern.

[0049] Step S104: Grow a second active layer on the surface of the front modulator region, and then etch away the first docking mask pattern;

[0050] Step S105: Create a second docking mask pattern in the area outside the front grating region and the rear grating region, and etch away the first active layer material in the front grating region and the rear grating region.

[0051] Step S106: Use docking growth technology to grow a third active layer in the front grating region and the rear grating region, then remove the second docking mask pattern, and fabricate a sampling grating in the front grating region and the rear grating region.

[0052] Step S107: Cladding and electrical contact layers are sequentially grown on the surface of the device, and a truncated shallow ridge waveguide structure is fabricated on the cladding and electrical contact layers.

[0053] Step S108: Etch electrical isolation trenches on the electrical contact layer to achieve electrical isolation between different areas;

[0054] Step S109: Fabricate P-side electrodes on the electrical contact layer in each region. After the substrate is thinned, fabricate N-side electrodes on the overall surface at the bottom of the substrate to complete the fabrication of the integrated device.

[0055] The method for fabricating photonic integrated devices provided in this embodiment integrates the gain region material and two modulator materials through one selected area epitaxial growth and one docking growth, integrating a wide-wavelength tunable laser with two electro-absorption modulators. Compared with the current two-dock fabrication technology, it saves one growth of the active layer, reduces the problem of docking interface defects caused by multiple docking epitaxial growths, and improves the reliability of the device; at the same time, it also saves manufacturing costs and provides a solution for the integration of wide-wavelength tunable lasers and single-ended dual electro-absorption modulators.

[0056] The following is combined with Figures 2-10 The above steps will be demonstrated and explained in detail.

[0057] As a specific embodiment, the steps of this manufacturing method include:

[0058] (1) Select an N-type indium phosphide substrate 10, and according to the function of the integrated device, divide the surface of the substrate 10 along the length direction into a front modulator region 1, a rear modulator region 2, a front grating region 3, a gain region 4, and a rear grating region 5, as follows: Figure 2 As shown in the diagram, the lengths of the front modulator region 1 and the rear modulator region 2 are both 150 micrometers, the length of the front grating region 3 is 50 micrometers, the length of the gain region 4 is 300 micrometers, and the length of the rear grating region 5 is 250 micrometers. It should be noted that there are 50-micrometer-spaced electrical isolation regions between each functional region to facilitate subsequent etching of electrical isolation trenches to achieve electrical isolation between the regions.

[0059] (2) A 150 nm thick silicon dioxide thin film is grown on the surface of substrate 10, and a selected area epitaxial mask pattern 11 is fabricated in gain region 4. The selected area epitaxial mask pattern 11 consists of two parallel stripes with the same length as gain region 4 and a preset spacing and width; Figure 3 As shown, Figure 3 This is a top view of the substrate surface. In the selected area epitaxial mask pattern 11, the length of the parallel strips is 300 micrometers, the width of the strips is 12 micrometers, and the spacing is 20 micrometers.

[0060] (3) The first active layer is grown on the substrate surface except for the selected area epitaxial mask pattern 11 using an MOCVD device. The principle of this step is that when the reactive gas reaches the mask surface, it diffuses around the mask pattern, thereby increasing the thickness of the area between the mask patterns.

[0061] The first active layer is an InGaAsP active layer, which, from bottom to top, includes a first lower waveguide layer 12, a first multiple quantum well layer 13, and a first upper waveguide layer 14. The first lower waveguide layer 12 has a thickness of 100 nm; the first multiple quantum well layer 13 comprises six interleaved quantum well layers and seven barrier layers, each quantum well layer having a thickness of 5 nm and each barrier layer having a thickness of 9 nm; the first upper waveguide layer 14 has a thickness of 100 nm.

[0062] (4) Remove the selected area epitaxial mask pattern 11 by hydrofluoric acid wet etching, and fabricate a first docking mask pattern in the area excluding the pre-modulator region 1. The first docking mask pattern is a silicon dioxide docking mask pattern with a mask thickness of 250 nm. Remove the first active layer on the surface of the pre-modulator region 1 outside the first docking mask pattern by ICP etching. The overall structure at this time is as follows: Figure 4 As shown.

[0063] (5) A second active layer is grown on the surface of the pre-modulator region 1 using an MOCVD device. The second active layer is an InGaAsP active layer. The photofluorescence wavelength of the second active layer in the pre-modulator region 1 is 30-60 nm shorter than that of the first active layer in the post-modulator region. From bottom to top, it includes a second lower waveguide layer 15, a second multiple quantum well layer 16, and a second upper waveguide layer 17. The thickness of the second lower waveguide layer 15 is 80 nm; the second multiple quantum well layer 16 contains 9 quantum well layers and 10 barrier layers that are interleaved, each quantum well layer is 10 nm thick, and each barrier layer is 5 nm thick; the thickness of the second upper waveguide layer 17 is 80 nm. The overall structure at this time is as follows: Figure 5 As shown.

[0064] It should be noted that, because the active layer of the pre-modulator region 1 needs to have a shorter photofluorescence wavelength than the active layer of the gain region 4, a single epitaxial growth cannot simultaneously meet the needs of the active layers in both the gain and modulation regions. Therefore, a silicon oxide mask is used for protection, the active layer previously grown in the pre-modulator region 1 is removed, and the active layer required for the pre-modulator region 1 is regrown.

[0065] (6) Remove the first docking mask pattern using hydrofluoric acid wet etching, and fabricate a second docking mask pattern 18 in the area outside the front grating region 3 and the rear grating region 5. The second docking mask pattern 18 is a silicon dioxide docking mask pattern with a thickness of 250 nm. Figure 6 As shown, Figure 6 This is a top view of the device at this time.

[0066] (7) The active material (InGaAsP material) of the rear grating region 5 and the front grating region 3 is removed by etching using the ICP method, which is the first active layer grown in step (4).

[0067] (8) A third active layer 19 is grown in the rear grating region 5 and the front grating region 3 using a docking growth technique. The third active layer 19 is made of InGaAsP material, and its photofluorescence wavelength is 150 nm smaller than that of the first active layer material in the gain region 4. Figure 7 As shown. The advantage of having a smaller photofluorescence wavelength in the grating region than in the gain region is that the laser emitted by the laser will not be absorbed by the grating material in the grating region, thus avoiding losses caused by material absorption.

[0068] (9) Remove the second docking mask pattern 18 by etching, and create grating 20 in the front grating area 3 and the rear grating area 5.

[0069] (10) A 1.5 μm thick InP cladding layer 21 and a 300 nm thick InGaAs electrical contact layer 22 are sequentially grown on the surface of the entire device, such as... Figure 8 As shown, a truncated shallow ridge waveguide structure is fabricated on cladding 21 and electrical contact layer 22. Please refer to [link to relevant documentation]. Figure 9 , Figure 9 This is a cross-sectional view of the device.

[0070] (11) An electrical isolation trench with a width of 50 micrometers is etched on the electrical contact layer 22 of the ridge waveguide between each region to achieve electrical isolation between the front modulator region 1, the rear modulator region 2, the front grating region 3, the gain region 4 and the rear grating region 5.

[0071] (12) P-side electrodes 23 are fabricated on the electrical contact layer 22 of the front modulator region 1, the rear modulator region 2, the front grating region 3, the gain region 4, and the rear grating region 5. After the substrate 10 is thinned, N-side electrodes 24 are fabricated on the bottom of the entire device to complete the fabrication of the photonic integrated device, such as... Figure 10 As shown.

[0072] The method in this embodiment integrates the gain region material and two modulator materials through one selected area epitaxial growth and one docking growth, integrating a wide-wavelength tunable laser with two electro-absorption modulators. Compared with the previous two docking preparation techniques, it saves one active layer growth, reduces the problem of docking interface defects caused by multiple docking epitaxial growths, and improves the reliability of the device. At the same time, it also saves manufacturing costs and provides a solution for the integration of wide-wavelength tunable lasers and single-ended dual electro-absorption modulators.

[0073] Example 2

[0074] This invention also provides a structure for a photonic integrated device, which is fabricated using the photonic integrated device fabrication method described in Example 1. Figure 10 As shown, the device comprises, from bottom to top, the following components: N-side electrode 24, substrate 10, active layer, cladding layer 21, electrical contact layer 22, and P-side electrode 23;

[0075] The laser is divided into a front modulator region 1, a rear modulator region 2, a front grating region 3, a gain region 4, and a rear grating region 5, starting from one side and extending along its length.

[0076] Among them, the bandgap width shift is achieved by selective epitaxial growth of the gain region 4 and the post-modulator region 2; the photofluorescence wavelength of the gain region 4 is 150~200nm longer than that of the materials in the front grating region 3 and the post-grating region 5, and the photofluorescence wavelength of the material in the front modulator region 1 is 30-60nm shorter than that of the post-modulator region 2.

[0077] In the integrated device structure provided in this embodiment, the bandgap width of the gain region and the post-modulator region is shifted through selective epitaxial growth of materials. Reasonable adjustment of the bandgap width can control the absorption and emission characteristics of photons in different regions. Therefore, shifting the bandgap width of the gain region helps improve optical gain efficiency and enhance optical signal intensity. Shifting the bandgap width of the post-modulator region facilitates effective electroabsorption modulation, precisely controlling the modulation depth and speed of the optical signal, thereby improving the overall photon transmission and modulation performance of the device. The photofluorescence wavelength of the gain region is 150-200 nm longer than that of the front and rear grating regions, creating a significant difference in its spectrum and providing a basis for wide-wavelength tunability. The photofluorescence wavelength of the material in the front modulator region is 30-60 nm shorter than that in the post-modulator region. This wavelength difference design facilitates the modulation of optical signals in different bands, improving the device's tuning flexibility and signal processing efficiency in optical communication systems.

[0078] Simultaneously, this device integrates a wide-wavelength tunable laser with two electro-absorption modulators, forming a compact photonic integrated device structure. This integrated design reduces connection losses between devices and optical mode mismatch issues, improving the compatibility and stability of the photonic integrated system. The longer photofluorescence wavelength in the gain region facilitates more efficient optical amplification and broadens the laser's tuning range; the shorter photofluorescence wavelength in the pre-modulator region facilitates fast-response electro-absorption modulation, increasing the signal modulation rate. This structure, optimized for material properties, enables the device to better meet the requirements of optical communication systems for high speed, high capacity, and flexible wavelength tuning.

[0079] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for fabricating a photonic integrated device, characterized in that, include: The substrate is laid out by dividing the substrate surface along the length direction into a front modulator region, a rear modulator region, a front grating region, a gain region, and a rear grating region. A selected area epitaxial mask pattern is fabricated on the surface of the gain region of the substrate. The selected area epitaxial mask pattern consists of two parallel strips with the same length as the gain region and a preset spacing and width. A first active layer is grown on the substrate surface in the area excluding the selected area epitaxial mask pattern. Then, the selected area epitaxial mask pattern is etched away, and a first docking mask pattern is fabricated in the area excluding the pre modulator region. The first active layer is etched away in the area excluding the first docking mask pattern. The first active layer includes a first lower waveguide layer, a first multiple quantum well layer and a first upper waveguide layer from bottom to top. A second active layer is grown on the surface of the pre-modulator region, and then the first docking mask pattern is removed by etching. A second docking mask pattern is fabricated in the area outside the front grating region and the rear grating region, and the first active layer of the front grating region and the rear grating region is etched away. A third active layer is grown in the front grating region and the rear grating region using docking growth technology. Then, the second docking mask pattern is removed, and sampling gratings are fabricated in the front grating region and the rear grating region. A cladding layer and an electrical contact layer are sequentially grown on the surface of the entire device, and an inverted shallow ridge waveguide structure is fabricated on the cladding layer and the electrical contact layer. Electrical isolation trenches are etched on the electrical contact layer to achieve electrical isolation between different areas; P-side electrodes are fabricated on the electrical contact layers in each region. After the substrate is thinned, N-side electrodes are fabricated on the overall surface at the bottom of the substrate to complete the fabrication of the integrated device.

2. The method for fabricating a photonic integrated device according to claim 1, characterized in that, The photofluorescence wavelength of the third active layer in the front and rear grating regions is 150–200 nm shorter than that of the first active layer in the gain region.

3. The method for fabricating a photonic integrated device according to claim 1, characterized in that, The photofluorescence wavelength of the second active layer in the front modulator region is 30-60 nm shorter than that of the first active layer in the rear modulator region.

4. The method for fabricating a photonic integrated device according to claim 1, characterized in that, The lengths of the front modulator region and the rear modulator region are both 150 micrometers, the length of the front grating region is 50 micrometers, the length of the gain region is 300 micrometers, and the length of the rear grating region is 250 micrometers. An electrical isolation region with a spacing of 50 micrometers is provided between adjacent regions.

5. The method for fabricating a photonic integrated device according to claim 1, characterized in that, The thickness of both the first lower waveguide layer and the first upper waveguide layer is 100 nm.

6. The method for fabricating a photonic integrated device according to claim 1, characterized in that, The first multi-quantum well layer is formed by the interpenetrating growth of multiple quantum well layers and multiple barrier layers.

7. The method for fabricating a photonic integrated device according to claim 5, characterized in that, The second active layer comprises, from bottom to top, a second lower waveguide layer, a second multiple quantum well layer, and a second upper waveguide layer; the thickness of the second lower waveguide layer and the second upper waveguide layer is 80 nm, and the thickness of the second multiple quantum well layer is greater than the thickness of the first multiple quantum well layer.

8. The method for fabricating a photonic integrated device according to claim 1, characterized in that, The method for removing the first active layer of the front and rear grating regions employs ICP etching.

9. The method for fabricating a photonic integrated device according to claim 1, characterized in that, The width of the electrical isolation trench is 50 micrometers.

10. A structure of a photonic integrated device, characterized in that, The device is fabricated using the preparation method described in any one of claims 1-9 above, and the device comprises, from bottom to top, an N-side electrode, a substrate, an active layer, a cladding layer, an electrical contact layer, and a P-side electrode; The device is divided into a front modulator region, a rear modulator region, a front grating region, a gain region, and a rear grating region, starting from one side and proceeding along its length. The first active layer comprises, from bottom to top, a first lower waveguide layer, a first multiple quantum well layer, and a first upper waveguide layer; the gain region and the post-modulator region achieve bandgap shift through selective epitaxial growth of materials; the photofluorescence wavelength of the gain region is 150-200 nm longer than that of the grating region material, and the photofluorescence wavelength of the pre-modulator region material is 30-60 nm shorter than that of the post-modulator region material.

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