A semiconductor optical amplifier and its fabrication method

Abstract

This invention relates to a semiconductor optical amplifier and its fabrication method. The semiconductor optical amplifier comprises, in sequence along its length: a passive refractive index guiding region, an active refractive index guiding region, an active gain guiding region, and a passive gain guiding region; a first electrode is formed on the active refractive index guiding region; a second electrode is formed on the active gain guiding region; the passive refractive index guiding region and the passive gain guiding region, from top to bottom, comprise: a SiNx layer, a p-InP layer, a passive InGaAs layer, an n-InP layer, an InP substrate, and an n-metal layer; the active layers at the input and output ends of the semiconductor optical amplifier of this invention are replaced with passive InGaAs layers to protect the aluminum-containing active regions and prevent them from direct contact with air, thereby effectively preventing oxidation of the aluminum-containing active regions; simultaneously, the passive InGaAs layer is not a dielectric, and its excellent thermal conductivity allows the device to dissipate heat more effectively under high-power operating conditions, further improving its operational stability and reliability.

Description

Technical Field

[0001] This invention relates to the field of optoelectronics, and more specifically, to a semiconductor optical amplifier and its fabrication method. Background Technology

[0002] With the rapid development of modern optical communication networks, optical signal amplification technology has become a key component for efficiently achieving long-distance, high-capacity optical transmission. Semiconductor optical amplifiers are widely used in wavelength division multiplexing systems, fiber optic sensing, and optical switching equipment due to their low cost, small size, light weight, low power consumption, and ease of integration.

[0003] However, in traditional semiconductor optical amplifiers, the input and output ends are often exposed to air after fabrication but before the anti-reflection coating is deposited. This easily leads to oxidation of the aluminum-containing active region, affecting the device's lifespan and reliability. Moreover, under high output power operating conditions, the thin anti-reflection coating on the semiconductor optical amplifier's end face is easily burned out, reducing the device's reliability and lifespan, and greatly limiting its application scenarios. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of poor stability and reliability of existing semiconductor optical amplifiers, and to provide a semiconductor optical amplifier and its preparation method, which effectively improves the stability and reliability of the semiconductor optical amplifier, thereby effectively improving the performance of the semiconductor optical amplifier.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] A semiconductor optical amplifier is provided, comprising, in sequence along its length: a passive refractive index guiding region, an active refractive index guiding region, an active gain guiding region, and a passive gain guiding region; a first electrode is formed on the active refractive index guiding region; a second electrode is formed on the active gain guiding region; the passive refractive index guiding region and the active refractive index guiding region together constitute the refractive index guiding region; the active gain guiding region and the passive gain guiding region together constitute the gain guiding region.

[0007] The passive refractive index guiding region and the passive gain guiding region, from top to bottom, include: a SiNx layer, a p-InP layer, a passive InGaAs layer, an n-InP layer, an InP substrate, and an n-metal layer.

[0008] The active refractive index guiding region and the active gain guiding region, from top to bottom, include: a p-metal layer, a p-Ohmic Contact layer, a p-InP layer, an InGaAsP etch stop layer, an electron blocking layer, a SCH layer, an MQW (AlGaInAs) multiple quantum well layer, an SCH layer, an n-InP layer, an InP substrate, and an n-metal layer.

[0009] The present invention discloses a semiconductor optical amplifier in which the active layers at the input and output ends of the semiconductor optical amplifier are replaced with passive InGaAs layers to protect the aluminum-containing active regions and prevent them from direct contact with air, thereby effectively preventing oxidation of the aluminum-containing active regions. At the same time, the passive InGaAs layer is not a dielectric, and its excellent thermal conductivity enables the device to dissipate heat more effectively under high-power operating conditions, further improving its operating stability and reliability.

[0010] Furthermore, the active layer, from top to bottom, includes: an InGaAsP etch stop layer, an electron blocking layer, a SCH layer, an MQW (AlGaInAs) multi-quantum well layer, and another SCH layer.

[0011] Furthermore, the aluminum-containing active region comprises, from top to bottom: an electron blocking layer, a SCH layer, an MQW (AlGaInAs) multiple quantum well layer, and another SCH layer.

[0012] Furthermore, the passive InGaAs layers of the passive refractive index guiding region and the passive gain guiding region cover a thickness direction from above the n-InP layer to above the InGaAsP etch stop layer; the p-InP layers of the passive refractive index guiding region and the passive gain guiding region cover a thickness direction from above the InGaAsP etch stop layer to above the p-Ohmic Contact layer.

[0013] Furthermore, the gain guiding region is a wedge-shaped gain guiding region, which includes forming a wedge-shaped waveguide structure by etching or forming a wedge-shaped window by etching.

[0014] Furthermore, the cone angle of the wedge-shaped gain guide region is 0 to 6°; the centerline of the wedge-shaped gain guide region is the line connecting the midpoints of the two ends of the wedge in the length direction; or, the wedge-shaped gain guide region is tilted to one side, and the angle between the centerline of the wedge and the length direction of the semiconductor optical amplifier is 0 to 12°.

[0015] Furthermore, the refractive index guiding region is an Euler curved ridge waveguide structure, a straight ridge waveguide structure, or an inclined ridge waveguide structure; the etching depth of the refractive index guiding region is from the p-Ohmic Contact layer to the InGaAsP stop layer.

[0016] Furthermore, the Euler curved ridge waveguide structure has a bending radius of 300–800 μm, a bending angle of 5–12°, and a width of 1.4–6 μm; the tilt angle of the tilted ridge waveguide structure is 5–12°; the length of the passive refractive index guiding region in the longitudinal direction is 0.3–0.8 mm; the length of the active refractive index guiding region in the longitudinal direction is 0.5–2 mm; the length of the active gain guiding region in the longitudinal direction is 1–4 mm; and the length of the passive gain guiding region in the longitudinal direction is 0.3–0.8 mm.

[0017] Furthermore, there are no electrical contacts on the passive refractive index guiding region and no electrical contacts on the passive gain guiding region; an electrical isolation region is provided between the first electrode and the second electrode, and the length of the electrical isolation region between the first electrode and the second electrode is 0.005 to 0.05 mm; or, the first electrode and the second electrode are electrically connected.

[0018] Furthermore, beam disruptors are provided on both sides of the active refractive index guiding region.

[0019] Furthermore, the beam disruptor has a parallelogram structure with a short side length of 5–15 μm, and the short side is parallel to the length direction of the semiconductor optical amplifier; the angle between the long side and the short side is 30–60°, and the projected length of the long side in the direction of the short side is 15–200 μm; the shortest distance of the beam disruptor from the perpendicular bisector of the output end of the refractive index guiding region in the width direction of the semiconductor optical amplifier is 5–30 μm; and the shortest distance of the beam disruptor from the output end of the refractive index guiding region in the length direction of the semiconductor optical amplifier is 5–30 μm.

[0020] The present invention also provides a method for fabricating the above-described semiconductor optical amplifier, comprising the following steps:

[0021] S1. An InP epitaxial wafer is obtained by sequentially growing an n-InP layer, a SCH layer, an MQW (AlGaInAs) multiple quantum well layer, an electron blocking layer, an InGaAsP etch stop layer, a p-InP layer, and a p-Ohmic Contact layer on an InP substrate.

[0022] S2. Fabrication of the protective platform: SiNx is deposited, and a protective platform is photolithographically formed on the InP epitaxial wafer;

[0023] S3. Fabrication of passive InGaAs layer: The passive InGaAs layer is fabricated by epitaxial growth;

[0024] S4. Preparation of p-InP layer: The p-InP layer is prepared by epitaxial growth, and SiNx is removed;

[0025] S5. Fabrication of waveguide structures for refractive index guiding regions: Deposition of SiNx, photolithography of waveguide structures for passive and active refractive index guiding regions;

[0026] S6. Fabrication of beam disruptor structure: deposit SiNx, photolithography of beam disruptor structure, and removal of photoresist;

[0027] S7. Electrode fabrication: deposit SiNx, expose the active refractive index guiding region and active gain guiding region window, etch the SiNx layer to expose the p-Ohmic Contact layer, fabricate the p-metal layer, thin the substrate, fabricate the n-metal layer, and perform thermal annealing.

[0028] Furthermore, P-electrode metals were prepared by electron beam evaporation, with the preparation order being: Ti, Pt, Au; N-electrode metals were prepared by electron beam evaporation, with the preparation order being: Ni, Ge, Au; the thickness of the substrate after thinning was 100–200 μm.

[0029] Compared with the prior art, the beneficial effects of the present invention are:

[0030] The present invention discloses a semiconductor optical amplifier and its fabrication method. The active layers at the input and output ends of the semiconductor optical amplifier are replaced with passive InGaAs layers to protect the aluminum-containing active regions and prevent them from direct contact with air, thereby effectively preventing oxidation of the aluminum-containing active regions. At the same time, the passive InGaAs layer is not a dielectric, and its excellent thermal conductivity enables the device to dissipate heat more effectively under high-power operating conditions, further improving its operational stability and reliability. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the overall structure of the semiconductor optical amplifier in Example 1;

[0032] Figure 2 This is a schematic diagram of the semiconductor optical amplifier from another perspective in Embodiment 1;

[0033] Figure 3 This is a schematic diagram of the preparation process in Example 15;

[0034] Figure 4 This is a schematic diagram of the metal layer structure in Example 15;

[0035] Figure 5 This is a schematic diagram of the overall structure of the semiconductor optical amplifier in Example 2;

[0036] Figure 6 This is a schematic diagram of the overall structure of the semiconductor optical amplifier in Example 3;

[0037] Figure 7This is a schematic diagram of the overall structure of the semiconductor optical amplifier in Example 4;

[0038] Figure 8 This is a schematic diagram of the overall structure of the semiconductor optical amplifier in Example 5;

[0039] Figure 9 This is a schematic diagram of the overall structure of the semiconductor optical amplifier in Example 6;

[0040] Figure 10 This is a schematic diagram of the overall structure of the semiconductor optical amplifier in Example 7;

[0041] Figure 11 This is a schematic diagram of the overall structure of the semiconductor optical amplifier in Example 8;

[0042] Figure 12 This is a schematic diagram of the overall structure of the semiconductor optical amplifier in Example 9;

[0043] Figure 13 This is a schematic diagram of the overall structure of the semiconductor optical amplifier in Example 10;

[0044] Figure 14 This is a schematic diagram of the overall structure of the semiconductor optical amplifier in Example 11;

[0045] Figure 15 This is a schematic diagram of the overall structure of the semiconductor optical amplifier in Example 12;

[0046] In the attached diagram: 1. Passive refractive index guiding region; 2. Active refractive index guiding region; 3. Active gain guiding region; 4. Passive gain guiding region; 5. First electrode; 6. Second electrode; 7. SiNx layer; 8. p-InP layer; 9. Passive InGaAs layer; 10. n-InP layer; 11. InP substrate; 12. n-metal layer; 13. p-metal layer; 14. p-Ohmic Contact layer; 15. InGaAsP etch stop layer; 16. Electron blocking layer; 17. SCH layer; 18. MQW (AlGaInAs) multiple quantum well layer; 19. Beam spoiler. Detailed Implementation

[0047] The present invention will be further described below with reference to specific embodiments. The accompanying drawings are for illustrative purposes only, representing schematic diagrams rather than actual physical objects, and should not be construed as limiting the scope of this patent. To better illustrate the embodiments of the present invention, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0048] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0049] Example 1

[0050] This embodiment is a first embodiment of a semiconductor optical amplifier, such as... Figure 1 and Figure 2 As shown, the region comprises, in sequence along its length: a passive refractive index guiding region 1, an active refractive index guiding region 2, an active gain guiding region 3, and a passive gain guiding region 4; a first electrode 5 is formed on the active refractive index guiding region 2; a second electrode 6 is formed on the active gain guiding region 3; the passive refractive index guiding region 1 and the active refractive index guiding region 2 together constitute the refractive index guiding region; the active gain guiding region 3 and the passive gain guiding region 4 together constitute the gain guiding region.

[0051] The passive refractive index guiding region 1 and the passive gain guiding region 4, from top to bottom, include: SiNx layer 7, p-InP layer 8, InGaAs passive layer 9, n-InP layer 10, InP substrate 11 and n-metal layer 12.

[0052] The active refractive index guiding region 2 and the active gain guiding region 3, from top to bottom, include: a p-metal layer 13, a p-Ohmic Contact layer 14, a p-InP layer 8, an InGaAsP etch stop layer 15, an electron blocking layer 16, a SCH layer 17, an MQW multiple quantum well layer 18, an n-InP layer 10, an InP substrate 11, and an n-metal layer 12.

[0053] The passive InGaAs layer 9 of the passive refractive index guiding region 1 and the passive gain guiding region 4 covers an area from above the n-InP layer 10 to above the InGaAsP etch stop layer 15 in the thickness direction; the p-InP layer 8 of the passive refractive index guiding region 1 and the passive gain guiding region 4 covers an area from above the InGaAsP etch stop layer 15 to above the p-Ohmic Contact layer 14 in the thickness direction.

[0054] In this embodiment, the gain guiding region is a wedge-shaped gain guiding region, which is formed by etching to create a wedge-shaped window.

[0055] In this embodiment, the cone angle of the wedge-shaped gain guide region is 0 to 6°; the centerline of the wedge-shaped gain guide region is the line connecting the midpoints of the two ends of the wedge in the length direction; or, the wedge-shaped gain guide region is tilted to one side, and the angle between the centerline of the wedge and the length direction of the semiconductor optical amplifier is 0 to 12°.

[0056] In this embodiment, the refractive index guiding region is an Euler curved ridge waveguide structure; the etching depth of the refractive index guiding region is from the p-Ohmic Contact layer 14 to the InGaAsP etching stop layer 15.

[0057] In this embodiment, the Euler curved ridge waveguide structure has a bending radius of 300–800 μm, a bending angle of 5–12°, and a width of 1.4–6 μm; the passive refractive index guiding region 1 has a length of 0.3–0.8 mm in the longitudinal direction; the active refractive index guiding region 2 has a length of 0.5–2 mm in the longitudinal direction; the active gain guiding region 3 has a length of 1–4 mm in the longitudinal direction; and the passive gain guiding region 4 has a length of 0.3–0.8 mm in the longitudinal direction.

[0058] In this embodiment, there are no electrical contacts on the passive refractive index guiding region 1 and the passive gain guiding region 4; an electrical isolation region is provided between the first electrode 5 and the second electrode 6, and the length of the electrical isolation region between the first electrode 5 and the second electrode 6 is 0.005 to 0.05 mm.

[0059] In this embodiment, beam disruptors 19 are provided on both sides of the active refractive index guiding region 2.

[0060] In this embodiment, the beam disruptor 19 has a parallelogram structure with a short side length of 5–15 μm, and the short side is parallel to the length direction of the semiconductor optical amplifier; the angle between the long side and the short side is 30–60°, and the projected length of the long side in the direction of the short side is 15–200 μm; the shortest distance of the beam disruptor 19 from the perpendicular bisector of the output end of the refractive index guiding region in the width direction of the semiconductor optical amplifier is 5–30 μm; and the shortest distance of the beam disruptor 19 from the output end of the refractive index guiding region in the length direction of the semiconductor optical amplifier is 5–30 μm.

[0061] In this embodiment, the active layer, from top to bottom, includes: an InGaAsP etch stop layer 15, an electron blocking layer 16, a SCH layer 17, an MQW (AlGaInAs) multiple quantum well layer 18, and another SCH layer 17.

[0062] In this embodiment, the aluminum-containing active region comprises, from top to bottom, an electron blocking layer 16, a SCH layer 17, an MQW (AlGaInAs) multiple quantum well layer 18, and another SCH layer 17.

[0063] This embodiment of a semiconductor optical amplifier comprises two parts: a refractive index guiding region and a gain guiding region. The refractive index guiding region is composed of a passive refractive index guiding region 1 and an active refractive index guiding region 2, and the gain guiding region is composed of an active gain guiding region 3 and a passive gain guiding region 4. Light is injected from the passive refractive index guiding region 1, amplified by the semiconductor optical amplifier, and output from the passive gain guiding region 4. In this embodiment of the semiconductor optical amplifier, there are two electrode regions: a first electrode 5 is formed on the active refractive index guiding region 2; and a second electrode 6 is formed on the active gain guiding region 3. There is no electrical contact between the first electrode 5 and the second electrode 6. Beam spoiler 19 structures for suppressing reverse traveling waves are fabricated on both sides of the active refractive index guiding region 2 near the active gain guiding region 3. In the semiconductor optical amplifier of this embodiment, the active layers of the passive refractive index guiding region 1 and the passive gain guiding region 4 are replaced with passive InGaAs layers 9, and there are no electrical contacts above the passive refractive index guiding region 1 and the passive gain guiding region 4. This embodiment differs from traditional semiconductor optical amplifier structures by replacing the active layers at the input end of the refractive index guiding region and the output end of the gain guiding region with passive InGaAs layers 9, thus protecting the aluminum-containing active regions and preventing direct contact with air. This also solves the problem of thin anti-reflection films being easily burned out under high-power operating conditions, improving the stability and lifespan of the semiconductor optical amplifier.

[0064] In summary, in this embodiment of a semiconductor optical amplifier, the active layers at the input and output ends of the semiconductor optical amplifier are replaced with passive InGaAs layers 9 to protect the aluminum-containing active regions and prevent them from directly contacting the air, thereby effectively preventing the oxidation of the aluminum-containing active regions. At the same time, the passive InGaAs layer 9 is not a dielectric, and its excellent thermal conductivity enables the device to dissipate heat more effectively under high-power operating conditions, further improving its operational stability and reliability.

[0065] Example 2

[0066] This embodiment is a second embodiment of a semiconductor optical amplifier. This embodiment is similar to the first embodiment, except that, as shown in the following... Figure 5 As shown, in Figure 1 Based on the structure shown, the beam spoilers 19 on both sides are removed.

[0067] Example 3

[0068] This embodiment is a third embodiment of a semiconductor optical amplifier. This embodiment is similar to Embodiment 1, except that, as shown in the following... Figure 6As shown, the gain guiding region is etched to form a wedge-shaped waveguide structure.

[0069] Example 4

[0070] This embodiment is a fourth embodiment of a semiconductor optical amplifier. This embodiment is similar to embodiment three, except that, as shown in the following... Figure 7 As shown, in Figure 6 Based on the structure shown, the beam spoilers 19 on both sides are removed.

[0071] Example 5

[0072] This embodiment is the fifth embodiment of a semiconductor optical amplifier. This embodiment is similar to Embodiment 1, except that, as shown in the following... Figure 8 As shown, with Figure 1 The difference in the structure shown is that the refractive index guiding region is a straight ridge waveguide structure.

[0073] Example 6

[0074] This embodiment is the sixth embodiment of a semiconductor optical amplifier. This embodiment is similar to embodiment five, except that, as Figure 9 As shown, in Figure 8 Based on the structure shown, the beam spoilers 19 on both sides are removed.

[0075] Example 7

[0076] This embodiment is the seventh embodiment of a semiconductor optical amplifier. This embodiment is similar to embodiment five, except that, as shown in the figure... Figure 10 As shown, with Figure 8 The difference in the structure shown is that the gain guiding region is etched to form a wedge-shaped waveguide structure.

[0077] Example 8

[0078] This embodiment is the eighth embodiment of a semiconductor optical amplifier. This embodiment is similar to embodiment seven, except that, as... Figure 11 As shown, in Figure 10 Based on the structure shown, the beam spoilers 19 on both sides are removed.

[0079] Example 9

[0080] This embodiment is the ninth embodiment of a semiconductor optical amplifier. This embodiment is similar to Embodiment 1, except that, as Figure 12 As shown, with Figure 1 The difference in the structure shown is that the refractive index guiding region is a tilted ridge waveguide structure with a tilt angle of 5° to 12°.

[0081] Example 10

[0082] This embodiment is the tenth embodiment of a semiconductor optical amplifier. This embodiment is similar to embodiment nine, except that, as Figure 13 As shown, in Figure 12 Based on the structure shown, the beam spoilers 19 on both sides are removed.

[0083] Example 11

[0084] This embodiment is the eleventh embodiment of a semiconductor optical amplifier. This embodiment is similar to embodiment nine, except that, as shown in the figure... Figure 14 As shown, with Figure 12 The difference in the structure shown is that the gain guiding region is etched to form a wedge-shaped waveguide structure.

[0085] Example 12

[0086] This embodiment is the twelfth embodiment of a semiconductor optical amplifier. This embodiment is similar to embodiment eleven, except that, as shown in the figure... Figure 15 As shown, in Figure 14 Based on the structure shown, the beam spoilers 19 on both sides are removed.

[0087] Example 13

[0088] This embodiment is the thirteenth embodiment of a semiconductor optical amplifier. This embodiment is similar to the first embodiment, except that there may be no electrical isolation region between the first electrode 5 and the second electrode 6, that is, the first electrode 5 and the second electrode 6 are connected to form one electrode.

[0089] Example 14

[0090] This embodiment is a first embodiment of a method for fabricating a semiconductor optical amplifier, used to fabricate the semiconductor optical amplifier structure described in Embodiment 1, and includes the following steps:

[0091] S1. On an InP substrate 11, an n-InP layer 10, a SCH layer 17, an MQW (AlGaInAs) multiple quantum well layer 16, an electron blocking layer 16, an InGaAsP etch stop layer 15, a p-InP layer 8, and a p-Ohmic Contact layer 14 are epitaxially grown sequentially to obtain an InP epitaxial wafer.

[0092] S2. Fabrication of the protective platform: SiNx is deposited, and a protective platform is photolithographically formed on the InP epitaxial wafer;

[0093] S3. Preparation of passive InGaAs layer 9: The passive InGaAs layer 9 is prepared by epitaxial growth;

[0094] S4. Preparation of p-InP layer 8: The p-InP layer 8 is prepared by epitaxial growth, and SiNx is removed;

[0095] S5. Fabrication of waveguide structure for refractive index guiding region: deposit SiNx, photolithography of waveguide structure for refractive index guiding region;

[0096] S6. Fabrication of beam disruptor 19 structure: deposit SiNx, photolithography of beam disruptor 19 structure, and removal of photoresist;

[0097] S7. Electrode fabrication: deposit SiNx, expose the electrode windows corresponding to the active refractive index guiding region 2 and the active gain guiding region 3, etch the SiNx layer 7 to expose the p-Ohmic Contact layer 14, fabricate the p-metal layer 13, thin the substrate, fabricate the n-metal layer 12, and perform thermal annealing.

[0098] The thickness of the SiNx deposited in step S2 ranges from 200 to 300 nm; the length of the protection platform in the length direction of the semiconductor optical amplifier is the sum of the length of the active refractive index guiding region 2 and the length of the active gain guiding region 3, and the coverage range is 1.5 to 6 mm. The thickness coverage range of the protection platform is from above the n-InP layer 10 to above the SiNx.

[0099] In step S3, the thickness of the epitaxially grown InGaAs passive waveguide layer extends from above the n-InP layer 10 to above the InGaAsP etch stop layer 15.

[0100] In step S4, the thickness of the epitaxially grown p-InP layer 8 extends from above the InGaAsP etch stop layer 15 to above the p-Ohmic Contact layer 14.

[0101] The thickness of the SiNx deposited in step S5 ranges from 150 to 200 nm. The refractive index guiding region is an Euler curved ridge waveguide structure with a bending radius of 300 to 800 μm, a bending angle of 5 to 12°, a ridge width of 1.4 to 6 μm, and a length range of 0.8 to 2.8 mm in the longitudinal direction.

[0102] The thickness of the SiNx deposited in step S6 ranges from 150 to 200 nm. The beam disruptor 19 has a parallelogram structure with a short side length of 5 to 15 μm, which is parallel to the length direction of the semiconductor optical amplifier. The angle between the long side and the short side is 30 to 60°, and the projected length of the long side in the direction of the short side is 15 to 200 μm. The closest distance of the beam disruptor 19 to the perpendicular bisector of the output end of the Euler curved ridge waveguide in the width direction of the semiconductor optical amplifier is 5 to 30 μm. The closest distance of the beam disruptor 19 to the output end of the Euler curved ridge waveguide in the length direction of the semiconductor optical amplifier is 5 to 30 μm.

[0103] In step S7, the thickness of the deposited SiNx ranges from 150 to 200 nm. The width of the window in the active refractive index guiding region 2 is 0.1 to 0.3 μm smaller than the ridge width of the Euler curved ridge waveguide, and the length is 0.5 to 2 mm. The cone angle of the active gain guiding region 3 is 0 to 6°, the length is 1 to 4 mm, and the angle between the wedge centerline and the length direction of the semiconductor optical amplifier is 0 to 12°.

[0104] The metals of the p-metal layer 13 prepared in step S7 are Ti, Pt, and Au; the metals of the n-metal layer 12 are Ni, Ge, and Au.

[0105] Example 15

[0106] This embodiment is a second embodiment of a semiconductor optical amplifier fabrication method, combined with... Figure 3 The preparation method of the present invention will be described in further detail, including the following steps:

[0107] Step 1: On an InP substrate 11, an n-InP layer 10, a SCH layer 17, an MQW (AlGaInAs) multiple quantum well layer 18, an electron blocking layer 16, an InGaAsP etch stop layer 15, a p-InP layer 8, and a p-OhmicContact layer 14 are sequentially epitaxially grown using MOCVD to obtain an InP epitaxial wafer, as shown below. Figure 3 As shown in (a); SiNx is deposited on an InP epitaxial wafer, a protective plateau pattern is exposed, and ICP etching is performed down to the n-clad layer to form a protective plateau, as shown in (a). Figure 3 As shown in (b) of the diagram.

[0108] Step 2: A passive InGaAs layer is epitaxially grown using MOVPE until it is at the same height as the InGaAsP stop layer, as shown below. Figure 3 As shown in (c) in the figure.

[0109] Step 3: MOVPE epitaxial growth of p-InP layer 8 to the same height as p-Ohmic Contact layer 14; RIE etching to remove SiNx, as shown. Figure 3 As shown in (d) in the figure.

[0110] Step 4: Deposit SiNx using ICP-VD, such as... Figure 3 As shown in (e) in the diagram.

[0111] Step 5: Apply a layer of photoresist, expose the refractive index guiding region, etch to the InGaAsP etch stop layer 15, and remove the photoresist. Figure 3 As shown in (f) in the figure.

[0112] Step 6: Deposit SiNx using ICP-VD, such as... Figure 3 As shown in (g) in the diagram.

[0113] Step 7: Spray a layer of photoresist, photolithographically etch the beam deflector 19 structure, etch it onto the InP substrate 11, and remove the photoresist. Figure 3 As shown in (h).

[0114] Step 8: Deposit SiNx using ICP-VD, such as... Figure 3 As shown in (i) in the diagram.

[0115] Step 9: Apply a layer of photoresist, photolithographically pattern the active refractive index guiding region 2 window and the active gain guiding region 3 window, etch the SiNx layer 7 until the p-Ohmic contact layer 14 is exposed, and remove the photoresist. Figure 3 As shown in (j) in the figure.

[0116] Step 10: Evaporate the P electrode, then perform electrode stripping, as follows... Figure 3 As shown in (k); the P electrode metal is Ti, Pt, Au, as shown in the figure. Figure 4 As shown in (a) in the figure.

[0117] Step 11: Evaporate the N electrode, such as... Figure 3 As shown in (l); the N electrode metal is Ni, Ge, Au, as shown in (l). Figure 4 As shown in (b) of the diagram.

[0118] Step 12: Thermal annealing forms p-type and n-type ohmic contacts, followed by cleavage to obtain the final semiconductor optical amplifier, such as... Figure 3 As shown in (m).

[0119] In this embodiment, the semiconductor optical amplifier can be in addition to InP-based semiconductor optical amplifiers, or other compound semiconductor optical amplifiers such as GaAs-based semiconductor optical amplifiers.

[0120] In this embodiment, in addition to MOCVD, other epitaxial growth methods can be used to grow the n-InP layer 10, SCH layer 17, MQW (AlGaInAs) multi-quantum well layer 18, SCH layer 17, electron blocking layer 16, InGaAsP etch stop layer 15, p-InP layer 8, and p-Ohmic Contact layer 14.

[0121] In this embodiment, in addition to ICPCVD, other deposition methods can also be used to deposit SiNx.

[0122] In this embodiment, in addition to RIE etching, other methods can be used to remove SiNx.

[0123] In this embodiment, in addition to MOVPE, other epitaxial growth methods can also be used to grow the passive InGaAs layer 9.

[0124] In this embodiment, in addition to MOVPE, other epitaxial growth methods can also be used to grow the p-InP layer 8.

[0125] In the specific implementation of the above embodiments, the technical features can be combined in any non-contradictory way. For the sake of brevity, not all possible combinations of the above technical features are described. However, as long as the combination of these technical features is not contradictory, it should be considered to be within the scope of this specification.

[0126] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A semiconductor optical amplifier, characterized in that, The region comprises, in sequence along its length: a passive refractive index guiding region (1), an active refractive index guiding region (2), an active gain guiding region (3), and a passive gain guiding region (4); a first electrode (5) is formed on the active refractive index guiding region (2); a second electrode (6) is formed on the active gain guiding region; the passive refractive index guiding region (1) and the active refractive index guiding region (2) together constitute the refractive index guiding region; the active gain guiding region (3) and the passive gain guiding region (4) together constitute the gain guiding region; The passive refractive index guiding region (1) and the passive gain guiding region (4) include, from top to bottom: SiNx layer (7), p-InP layer (8), passive InGaAs layer (9), n-InP layer (10), InP substrate (11) and n-metal layer (12); The active refractive index guiding region (2) and the active gain guiding region (3) include, from top to bottom, a p-metal layer (13), a p-Ohmic Contact layer (14), a p-InP layer (8), an InGaAsP etch stop layer (15), an electron blocking layer (16), a SCH layer (17), an MQW multi-quantum well layer (18), an SCH layer (17), an n-InP layer (10), an InP substrate (11), and an n-metal layer (12).

2. The semiconductor optical amplifier according to claim 1, characterized in that, The passive InGaAs layer (9) of the passive refractive index guiding region (1) and the passive gain guiding region (4) covers an area from above the n-InP layer (10) to above the InGaAsP etch stop layer (15) in the thickness direction; the p-InP layer (8) of the passive refractive index guiding region (1) and the passive gain guiding region (4) covers an area from above the InGaAsP etch stop layer (15) to above the p-OhmicContact layer (14) in the thickness direction.

3. The semiconductor optical amplifier according to claim 2, characterized in that, The gain guiding region is a wedge-shaped gain guiding region, which includes forming a wedge-shaped waveguide structure by etching or forming a wedge-shaped window by etching.

4. The semiconductor optical amplifier according to claim 3, characterized in that, The cone angle of the wedge-shaped gain guide region is 0 to 6°; the centerline of the wedge-shaped gain guide region is the line connecting the midpoints of the two ends of the wedge in the length direction; or, the wedge-shaped gain guide region is tilted to one side, and the angle between the centerline of the wedge and the length direction of the semiconductor optical amplifier is 0 to 12°.

5. The semiconductor optical amplifier according to claim 3, characterized in that, The refractive index guiding region is an Euler curved ridge waveguide structure, a straight ridge waveguide structure, or a tilted ridge waveguide structure; the etching depth of the refractive index guiding region is from the p-OhmicContact layer (14) to the InGaAsP etching stop layer (15); the Euler curved ridge waveguide structure has a bending radius of 300-800 μm, a bending angle of 5-12°, and a ridge width of 1.4-6 μm; the tilt angle of the tilted ridge waveguide structure is 5-12°; the length of the passive refractive index guiding region (1) in the longitudinal direction is 0.3-0.8 mm; the length of the active refractive index guiding region (2) in the longitudinal direction is 0.5-2 mm; the length of the active gain guiding region (3) in the longitudinal direction is 1-4 mm; the length of the passive gain guiding region (4) in the longitudinal direction is 0.3-0.8 mm.

6. The semiconductor optical amplifier according to claim 3, characterized in that, There are no electrical contacts on the passive refractive index guiding region (1) and no electrical contacts on the passive gain guiding region (4); an electrical isolation region is provided between the first electrode (5) and the second electrode (6), and the length of the electrical isolation region between the first electrode (5) and the second electrode (6) is 0.005 to 0.05 mm; or, the first electrode (5) and the second electrode (6) are electrically connected.

7. The semiconductor optical amplifier according to any one of claims 1 to 6, characterized in that, Beam spoilers (19) are provided on both sides of the active refractive index guiding region (2).

8. The semiconductor optical amplifier according to claim 7, characterized in that, The beam disruptor (19) has a parallelogram structure with a short side length of 5-15 μm, and the short side is parallel to the length direction of the semiconductor optical amplifier; the angle between the long side and the short side is 30-60°, and the projection length of the long side in the direction of the short side is 15-200 μm; the shortest distance of the beam disruptor (19) from the perpendicular bisector of the output end of the refractive index guiding region in the width direction of the semiconductor optical amplifier is 5-30 μm; and the shortest distance of the beam disruptor (19) from the output end of the refractive index guiding region in the length direction of the semiconductor optical amplifier is 5-30 μm.

9. The semiconductor optical amplifier according to claim 7, characterized in that, The input end of the passive refractive index guiding region (1) and the output end of the passive gain guiding region (4) are both coated with an antireflection film, and the reflectivity of the antireflection film is ≤0.5%.

10. A method for fabricating a semiconductor optical amplifier according to any one of claims 1 to 9, characterized in that, Includes the following steps: S1. An n-InP layer (10), a SCH layer (17), an MQW multi-quantum well layer (18), an electron blocking layer (16), an InGaAsP etch stop layer (15), a p-InP layer (8), and a p-Ohmic Contact layer (14) are epitaxially grown sequentially on an InP substrate (11) to obtain an InP epitaxial wafer. S2. Fabrication of the protective platform: SiNx is deposited, and a protective platform is photolithographically formed on the InP epitaxial wafer; S3. Preparation of passive InGaAs layer (9): The passive InGaAs layer (9) is prepared by epitaxial growth; S4. Preparation of p-InP layer (8): The p-InP layer (8) is prepared by epitaxial growth and SiNx is removed; S5. Preparation of waveguide structure of refractive index guiding region: deposit SiNx, photolithography of passive refractive index guiding region (1) and active refractive index guiding region (2) waveguide structure; S6. Fabrication of beam disruptor (19) structure: deposit SiNx, photolithography of beam disruptor (19) structure, and removal of photoresist; S7. Electrode preparation: deposit SiNx, etch the windows of the active refractive index guiding region (2) and the active gain guiding region (3), etch the SiNx layer (7) to expose the p-Ohmic Contact layer (14), prepare the p-metal layer (13), thin the substrate, prepare the n-metal layer (12), and perform thermal annealing.

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