阅读说明：本技术 单、双波长可切换的半导体激光器及其制备方法 (Semiconductor laser with switchable single wavelength and dual wavelength and preparation method thereof ) 是由 周寅利 张建伟 宁永强 张星 于 2021-08-11 设计创作，主要内容包括：本发明提供一种单、双波长可切换的半导体激光器及其制备方法,其中的半导体激光器包括外延结构,在外延结构上沿长度方向刻蚀形成脊波导,在脊波导上刻蚀形成半透半反式光栅,在外延结构上避开半透半反式光栅的位置制备形成P型电极层,P型电极层包括分布于半透半反式光栅两侧的增益开关区电极和光放大区电极；其中,半透半反式光栅、光放大区电极与前腔面构成第一激光腔,用于激发第一波长激光；增益开关区电极、增益开关区电极与半透半反式光栅之间的部分、半透半反式光栅和后腔面构成第二激光腔,用于激发第二波长激光。本发明能够实现单、双波长的自由切换,从而实现对泵浦碱金属原子的一个或两个能级的自由控制。(The invention provides a semiconductor laser with switchable single wavelength and double wavelengths and a preparation method thereof, wherein the semiconductor laser comprises an epitaxial structure, a ridge waveguide is formed on the epitaxial structure by etching along the length direction, a semi-transparent semi-reflective grating is formed on the ridge waveguide by etching, a P-type electrode layer is prepared and formed on the epitaxial structure at a position avoiding the semi-transparent semi-reflective grating, and the P-type electrode layer comprises a gain switch area electrode and a light amplification area electrode which are distributed at two sides of the semi-transparent semi-reflective grating; the semi-transparent semi-reflective grating, the light amplification area electrode and the front cavity surface form a first laser cavity for exciting first wavelength laser; the gain switch area electrode, the part between the gain switch area electrode and the semi-transparent semi-reflective grating, the semi-transparent semi-reflective grating and the rear cavity surface form a second laser cavity for exciting laser with a second wavelength. The invention can realize free switching of single and double wavelengths, thereby realizing free control of one or two energy levels of pumping alkali metal atoms.)

1. A semiconductor laser with switchable single wavelength and double wavelengths comprises an epitaxial structure and is characterized in that a ridge waveguide is formed on the epitaxial structure in an etching mode along the length direction, a semi-transparent semi-reflective grating is formed on the ridge waveguide in an etching mode, a P-type electrode layer is prepared and formed on the epitaxial structure at a position avoiding the semi-transparent semi-reflective grating, and the P-type electrode layer comprises gain switch area electrodes and light amplification area electrodes distributed on two sides of the semi-transparent semi-reflective grating;

respectively taking the gain switch area electrode, the light amplification area electrode and the semi-transparent semi-reflective grating as a gain switch area, a light amplification area and a grating area of the semiconductor laser, and taking an area between the gain switch area and the grating area as a light pump area of the semiconductor laser, wherein the widths of the gain switch area, the light amplification area and the light pump area are the same as the width of the semiconductor laser;

the grating area, the light amplification area and the front cavity surface of the semiconductor laser form a first laser cavity for exciting laser with a first wavelength; the back cavity surface of the semiconductor laser, the gain switch area, the optical pump area and the grating area form a second laser cavity for exciting laser with a second wavelength;

when the second laser cavity is opened, the semiconductor laser simultaneously outputs the first wavelength laser and the second wavelength laser; when the second laser cavity is closed, the semiconductor laser outputs only the laser light with the first wavelength.

2. The single-and dual-wavelength switchable semiconductor laser of claim 1 wherein a portion of said first wavelength lasing light exits said front facet and another portion returns to said first laser cavity and is transmitted through said half-transparent and half-reflective grating to said second laser cavity, said second wavelength lasing light being formed based on stokes shift principles.

3. The single-wavelength or dual-wavelength switchable semiconductor laser as claimed in claim 2, wherein the period of the transflective grating is 5 μm to 20 μm, the duty cycle of the transflective grating is 20% to 80%, and the grating order of the transflective grating is 10 th order to 80 th order; alternatively, the first and second electrodes may be,

the period of the semi-transparent semi-reflective grating is 0.5-5 μm, the duty ratio of the semi-transparent semi-reflective grating is 20-80%, and the grating order of the semi-transparent semi-reflective grating is 1-10 orders.

4. A single-and dual-wavelength switchable semiconductor laser as claimed in claim 2 or 3 wherein the epitaxial structure comprises an N-type electrode layer, a substrate layer, an N-type cladding layer, an N-type waveguide layer, an active layer, a P-type waveguide layer, a P-type cladding layer and a P-type cap layer, which are prepared in this order from bottom to top.

5. The single-and dual-wavelength switchable semiconductor laser of claim 4 wherein the transflective grating is etched from the P-type cap layer down to the P-type waveguide layer or to the P-type cladding layer.

6. The single-and dual-wavelength switchable semiconductor laser of claim 4 wherein said P-type cap layer etches both channels down to form said ridge waveguide, said P-type electrode layer further comprising an insulating layer fabricated on said P-type cap layer.

7. The single-and dual-wavelength switchable semiconductor laser of claim 6 wherein said substrate layer is an N-type GaAs material;

the N-type cladding layer is made of AlGaAs material, the weight part of Al is 0.1-0.6, and the N-type cladding layer is doped with AlThe agent is silicon, and the doping concentration of the silicon is 1E18-8E18/cm³；

The N-type waveguide layer is made of AlGaAs material, the weight part of Al is 0.05-0.7, the doping agent is silicon, and the doping concentration of the silicon is 1E 16-8E 18/cm³；

The active layer is of a potential barrier/quantum well/potential barrier structure, the active layer is made of AlGaAsP/InAlGaAs/AlGaAsP, the weight part of In is 0-0.5, the weight part of Al is 0-0.5, the weight part of P is 0-0.2, and the light-emitting waveband of the active layer is 700-1200 nm;

the P-type waveguide layer is made of AlGaAs material, the weight part of Al is 0.05-0.7, the doping agent is carbon, and the doping concentration of the carbon is 1E 16-8E 18/cm³；

The P-type cladding layer is made of AlGaAs material, the weight part of Al is 0.1-0.6, the doping agent is carbon, and the doping concentration of the carbon is 1E18-8E18/cm³；

The P-type cover layer is made of GaAs material, the dopant is carbon, and the doping concentration of the carbon is 1E 18-1E 20/cm³；

The insulating layer is SiO₂Or Si₃N₄A material;

the gain switch area electrode and the light amplification area electrode are made of alloy formed by more than two of titanium, platinum, gold, nickel and germanium.

8. The single-and dual-wavelength switchable semiconductor laser of claim 7 wherein the semiconductor laser has a cavity length of 500 μm to 5000 μm, a width of 200 μm to 800 μm, and a thickness of 100 μm to 300 μm;

the ridge width of the ridge waveguide is 1-200 μm, and the ridge length of the ridge waveguide is the same as the cavity length of the semiconductor laser;

the width of the channel is 30-60 mu m, the length of the channel is the same as the cavity length of the semiconductor laser, and the etching depth of the channel is 0.1-5 mu m;

the thickness of the N-type cladding layer is 0.5-3 mu m;

the thickness of the N-type waveguide layer is 0.1-10 mu m;

the thickness of the potential barrier in the active layer is 1 nm-200 nm, and the thickness of the quantum well in the active layer is 1 nm-20 nm;

the thickness of the P-type waveguide layer is 0.1-10 μm;

the thickness of the P-type cladding is 0.5-3 μm;

the thickness of the P-type cover layer is 0.1-3 mu m;

the thicknesses of the gain switch region electrode, the light amplification region electrode and the N-type electrode layer are all 200 nm-500 nm;

the length of the gain switch area electrode is 1-300 mu m, and the width of the gain switch area electrode is the same as that of the semiconductor laser;

the length of the optical pump area is 1-100 mu m;

the length of the light amplification region is 200-4950 μm;

the thickness of the insulating layer is 50 nm-1000 nm;

the etching depth of the semi-transparent semi-reflective grating is 0.1-10 mu m.

9. The single and dual wavelength switchable semiconductor laser of claim 8 wherein a highly reflective film is plated on a back facet of said semiconductor laser.

10. A preparation method of a semiconductor laser device with switchable single wavelength and dual wavelength is characterized by comprising the following steps:

s1, preparing an epitaxial structure;

s2, etching the epitaxial structure to form a ridge waveguide;

s3, etching the ridge waveguide to form a semi-transparent and semi-reflective grating;

s4, preparing a P-type electrode layer on the epitaxial structure at a position avoiding the semi-transparent semi-reflective grating; the P-type electrode layer comprises gain switch area electrodes and light amplification area electrodes distributed on two sides of the semi-transparent semi-reflective grating.

Technical Field

The invention relates to the technical field of semiconductor lasers, in particular to a semiconductor laser with switchable single and double wavelengths and a preparation method thereof.

Background

Semiconductor lasers have irreplaceable significance in the fields of communication, radar, electronic countermeasure, electromagnetic weaponry, medical imaging, security inspection, and the like.

Semiconductor laser pumped alkali metal lasers are a new type of high efficiency lasers that have been rapidly developed in recent years. The quantum well thermal management device has the advantages of high quantum efficiency, excellent thermal management performance, narrow line width and the like, is expected to realize high-power and high-beam-quality laser output, and has wide application prospects in the aspects of laser interference, laser damage, laser cooling, laser energy transmission, material processing, magnetic resonance imaging systems and the like. Common alkali metal atoms are potassium, rubidium and cesium, the corresponding absorption energy levels of the alkali metal atoms are different, the pumping energy levels of the potassium atoms are 766.70nm and 770.11nm, the pumping energy levels of the rubidium atoms are 780nm and 794nm, and the pumping energy levels of the cesium atoms are 852.35nm and 894.59 nm.

At present, the types of lasers for pumping alkali metal atoms mainly include Vertical Cavity Surface Emitting Lasers (VCSELs) and Distributed bragg reflector lasers (DFBs), both of which can only emit Laser light with a single wavelength, and if two wavelengths of Laser light are to be emitted simultaneously, two devices need to be integrated. A general dual-wavelength semiconductor laser, for example, a semiconductor laser using a Y-type waveguide, can emit laser light of two wavelengths at the same time, but cannot emit laser light of a single wavelength. If the laser can freely control and emit single wavelength or dual wavelength, free control of one or two energy levels of pumping alkali metal atoms can be realized, and the method has great significance for application of alkali metal atom lasers.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a semiconductor laser with switchable single wavelength and double wavelengths and a preparation method thereof.

In order to achieve the purpose, the invention adopts the following specific technical scheme:

the invention provides a semiconductor laser with switchable single wavelength and double wavelength, which comprises an epitaxial structure, wherein a ridge waveguide is formed on the epitaxial structure by etching along the length direction, a semi-transparent and semi-reflective grating is formed on the ridge waveguide by etching, a P-type electrode layer is prepared and formed on the epitaxial structure by avoiding the position of the semi-transparent and semi-reflective grating, and the P-type electrode layer comprises a gain switch area electrode and a light amplification area electrode which are distributed on two sides of the semi-transparent and semi-reflective grating; respectively taking the gain switch area electrode, the light amplification area electrode and the semi-transparent semi-reflective grating as a gain switch area, a light amplification area and a grating area of the semiconductor laser, and taking the area between the gain switch area and the grating area as an optical pump area of the semiconductor laser, wherein the widths of the gain switch area, the light amplification area and the optical pump area are the same as the width of the semiconductor laser; the grating area, the light amplification area and the front cavity surface of the semiconductor laser form a first laser cavity for exciting laser with a first wavelength; the back cavity surface, the gain switch area, the optical pump area and the grating area of the semiconductor laser form a second laser cavity for exciting laser with a second wavelength; when a second laser cavity is opened, the semiconductor laser simultaneously outputs laser light with a first wavelength and laser light with a second wavelength; when the second laser cavity is closed, the semiconductor laser outputs only the first wavelength laser light.

Preferably, a part of the laser light with the first wavelength is emitted from the front cavity surface, and the other part of the laser light with the first wavelength returns to the first laser cavity and is transmitted to the second laser cavity through the semi-transparent and semi-reflective grating, and the laser light with the second wavelength is formed based on the Stokes shift principle.

Preferably, the period of the semi-transparent and semi-reflective grating is 5-20 μm, the duty ratio of the semi-transparent and semi-reflective grating is 20-80%, and the grating order of the semi-transparent and semi-reflective grating is 10-80 orders; or the period of the semi-transparent and semi-reflective grating is 0.5-5 μm, the duty ratio of the semi-transparent and semi-reflective grating is 20-80%, and the grating order of the semi-transparent and semi-reflective grating is 1-10 orders.

Preferably, the epitaxial structure comprises an N-type electrode layer, a substrate layer, an N-type cladding layer, an N-type waveguide layer, an active layer, a P-type waveguide layer, a P-type cladding layer and a P-type covering layer which are sequentially prepared from bottom to top.

Preferably, the transflective grating is etched from the P-type cap layer down to the P-type waveguide layer or to the P-type cladding layer.

Preferably, the P-type cover layer is etched down to form two channels to form a ridge waveguide, and the P-type electrode layer further comprises an insulating layer prepared on the P-type cover layer.

Preferably, the substrate layer is an N-type GaAs material; the N-type cladding layer is made of AlGaAs material, Al accounts for 0.1-0.6 parts by weight, the dopant is silicon, and the doping concentration of the silicon is 1E18-8E18/cm³(ii) a The N-type waveguide layer is made of AlGaAs material, the weight part of Al is 0.05-0.7, the doping agent is silicon, and the doping concentration of the silicon is 1E 16-8E 18/cm³(ii) a The active layer is of a potential barrier/quantum well/potential barrier structure, the active layer is made of AlGaAsP/InAlGaAs/AlGaAsP, the weight part of In is 0-0.5, the weight part of Al is 0-0.5, the weight part of P is 0-0.2, and the light-emitting waveband of the active layer is 700-1200 nm; the P-type waveguide layer is made of AlGaAs material, Al accounts for 0.05-0.7 by weight, the doping agent is carbon, and the doping concentration of the carbon is 1E 16-8E 18/cm³(ii) a The P-type cladding layer is made of AlGaAs material, Al accounts for 0.1-0.6 parts by weight, the dopant is carbon, and the doping concentration of the carbon is 1E18-8E18/cm³(ii) a The P-type cover layer is made of GaAs material, the dopant is carbon, and the doping concentration of the carbon is 1E 18-1E 20/cm³(ii) a The insulating layer is SiO₂Or Si₃N₄A material; the gain switch area electrode and the light amplification area electrode are made of alloy formed by more than two of titanium, platinum, gold, nickel and germanium.

Preferably, the cavity length of the semiconductor laser is 500-5000 μm, the width is 200-800 μm, and the thickness is 100-300 μm; the ridge width of the ridge waveguide is 1-200 μm, and the ridge length of the ridge waveguide is the same as the cavity length of the semiconductor laser; the width of the channel is 30-60 μm, the length of the channel is the same as the cavity length of the semiconductor laser, and the etching depth of the channel is 0.1-5 μm; the thickness of the N-type cladding is 0.5-3 μm; the thickness of the N-type waveguide layer is 0.1-10 μm; the thickness of the potential barrier in the active layer is 1 nm-200 nm, and the thickness of the quantum well in the active layer is 1 nm-20 nm; the thickness of the P-type waveguide layer is 0.1-10 μm; the thickness of the P-type cladding is 0.5-3 μm; the thickness of the P-type cover layer is 0.1-3 mu m; the thicknesses of the gain switch region electrode, the light amplification region electrode and the N-type electrode layer are all 200 nm-500 nm; the length of the gain switch area electrode is 1-300 μm, and the width of the gain switch area electrode is the same as that of the semiconductor laser; the length of the optical pump area is 1-100 μm; the length of the light amplification region is 200-4950 μm; the thickness of the insulating layer is 50 nm-1000 nm; the etching depth of the semi-transparent semi-reflective grating is 0.1-10 μm.

Preferably, the rear cavity surface of the semiconductor laser is plated with a high-reflection film.

The invention provides a preparation method of a semiconductor laser with switchable single wavelength and dual wavelength, which comprises the following steps:

s1, preparing an epitaxial structure;

s2, etching the epitaxial structure to form a ridge waveguide;

s3, etching the ridge waveguide to form a semi-transparent and semi-reflective grating;

s4, preparing a P-type electrode layer on the epitaxial structure at a position avoiding the semi-transparent semi-reflective grating; the P-type electrode layer comprises gain switch area electrodes and light amplification area electrodes distributed on two sides of the semi-transparent semi-reflective grating.

The invention can obtain the following technical effects:

1. the switching of single and double wavelengths output by the semiconductor laser is realized through the gain switch region, so that the free control of one or two energy levels of pumping alkali metal atoms is realized.

2. The semiconductor laser realizes the switching of single and double wavelengths only by means of one on-chip integrated gain switch area, and the size of the semiconductor laser is consistent with that of a chip of the traditional semiconductor laser, so that the semiconductor laser has extremely high integration easiness.

3. The semiconductor laser capable of freely switching single-wavelength and double-wavelength lasing provided by the invention only comprises one grating structure, and the whole manufacturing process is simple.

4. Compared with the traditional semiconductor laser, the pumping modes for exciting the dual wavelengths are electroluminescence and photoluminescence respectively, and the invention belongs to a brand new dual-wavelength semiconductor laser with an electro-optical hybrid pumping mechanism.

Drawings

Fig. 1 is a schematic perspective view of a single-wavelength and dual-wavelength switchable semiconductor laser provided according to an embodiment of the present invention;

fig. 2 is a schematic cross-sectional view of a single, dual wavelength switchable semiconductor laser provided in accordance with an embodiment of the present invention;

FIG. 3 is a schematic diagram of gain ranges of the same gain material under optical pumping and electrical pumping according to an embodiment of the present invention;

fig. 4 is a schematic flow chart of a method for manufacturing a single-wavelength and dual-wavelength switchable semiconductor laser according to an embodiment of the present invention.

Wherein the reference numerals include: the semiconductor device comprises an N-type electrode layer 101, a substrate layer 102, an N-type cladding layer 103, an N-type waveguide layer 104, an active layer 105, a P-type waveguide layer 106, a P-type cladding layer 107, a P-type cap layer 108, an insulating layer 109, a light amplification region electrode 110, a P-type gain switch electrode 111, a gain switch region 210, an optical pump region 211, a grating region 212, an optical amplification region 213, a channel 301, a ridge waveguide 302 and a half-transparent and half-reflective grating 303.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, the same reference numerals are used for the same blocks. In the case of the same reference numerals, their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not to be construed as limiting the invention.

Fig. 1 and 2 show a three-dimensional structure and a cross-sectional structure of a single-wavelength and a two-wavelength switchable semiconductor laser according to an embodiment of the present invention.

As shown in fig. 1 and fig. 2, the single-wavelength and dual-wavelength switchable semiconductor laser provided by the embodiment of the present invention includes an epitaxial structure, where the epitaxial structure includes, from bottom to top, an N-type electrode layer 101, a substrate layer 102, an N-type cladding layer 103, an N-type waveguide layer 104, an active layer 105, a P-type waveguide layer 106, a P-type cladding layer 107, and a P-type cap layer 108, which are sequentially prepared.

Two channels 301 are etched downwards on the P-type cover layer 108 along the length direction of the semiconductor laser to form a ridge waveguide 302, the length of each channel 301 is the same as that of the ridge waveguide 302 and is the cavity length of the semiconductor laser, and a semi-transparent and semi-reflective grating 303 is etched on the ridge waveguide 302. The transflective grating 303 is etched from the P-type cap layer 108 down to the P-type waveguide layer 107 or to the P-type cladding layer 106. The reflection and transmission functions of the semi-transparent semi-reflective grating 303 to the laser are realized by controlling the period, the duty ratio and the etching depth of the semi-transparent semi-reflective grating 303, that is, the semi-transparent semi-reflective grating 303 can reflect part of the laser and transmit part of the laser.

The P-type electrode layer is prepared on the P-type cover layer 108, the P-type electrode layer comprises a patterned insulating layer 109 and a metal conducting layer, the insulating layer 109 is prepared on the P-type cover layer 108, the metal conducting layer is positioned on the insulating layer 109, the metal conducting layer comprises a light amplification area electrode 110 and a gain switch electrode 111 which are positioned on two sides of the semi-transparent and semi-reflective grating 303, the patterning purposes of the insulating layer 109 and the metal conducting layer are two, firstly, the position of the semi-transparent and semi-reflective grating 303 is avoided, and secondly, the light amplification area electrode 110 and the gain switch electrode 111 are distributed on two sides of the semi-transparent and semi-reflective grating 303.

As can be seen from fig. 1, the insulating layer 109 is grown only on the P-type cap layer 108, but not on the ridge waveguide 302, and the light amplification section electrode 110 and the gain switch electrode 111 are covered on the ridge waveguide 302.

The gain switch region electrode 111 is used as a gain switch region 210 of the semiconductor laser, the light amplification region electrode 110 is used as a light amplification region 212 of the semiconductor laser, the transflective grating 303 is used as a grating region 212 of the semiconductor laser, and a region between the gain switch region 210 and the grating region 212 is used as a light pump region 211 of the semiconductor laser.

Viewed from the perspective of fig. 2, the semiconductor laser sequentially includes, from left to right, a gain switch region 210, an optical pump region 211, a grating region 212, and an optical amplification region 213, the gain switch region 210 is close to the rear cavity surface of the semiconductor laser, the rear cavity surface of the semiconductor laser is plated with a high reflection film, the optical amplification region 213 is close to the front cavity surface of the semiconductor laser, the front cavity surface is a light-emitting surface of the semiconductor laser, and the light-emitting surface is a natural cleavage surface.

The grating region 212, the light amplification region 213, and the front cavity facet of the semiconductor laser constitute a first laser cavity of the semiconductor laser, which excites laser light of a first wavelength based on electroluminescence.

The back facet of the semiconductor laser, the gain switch region 210, the optical pump region 211, and the grating region 212 constitute a second laser cavity of the semiconductor laser, which excites the laser light of the second wavelength based on the photoluminescence of the laser light of the first wavelength.

When a second laser cavity is opened, the semiconductor laser simultaneously outputs laser light with a first wavelength and laser light with a second wavelength; when the second laser cavity is closed, the semiconductor laser outputs only the first wavelength laser light.

In some embodiments of the present invention, the semiconductor laser has a cavity length of 500 μm to 5000 μm, a width of 200 μm to 800 μm, and a thickness of 100 μm to 300 μm.

The ridge width of the ridge waveguide 302 is 1 μm to 200 μm, and the ridge length of the ridge waveguide is the same as the cavity length of the semiconductor laser.

The width of the channel 301 is 30-60 μm, the length of the channel 301 is the same as the cavity length of the semiconductor laser, and the etching depth of the channel 301 is 0.1-5 μm.

The length of the gain switching region 210 is 1 μm to 300 μm, and the width of the gain switching region electrode is the same as the width of the semiconductor laser. When the gain switching region 210 is powered on, current is injected into the active layer 105 to generate optical gain, which increases with increasing current, and when the optical gain is equal to the optical loss time, laser light can pass through the gain switching region 210; when the gain switching region 210 is not powered on, the gain switching region 210 has a great light absorption loss, and the laser light cannot pass through the gain switching region 210.

The length of the light pump region 211 is 1 μm to 100 μm, and the width of the light pump region 211 is the same as the width of the semiconductor laser.

The length of the light amplification region 213 is 200 μm to 4950 μm, and the width of the light amplification region 213 is the same as the width of the semiconductor laser.

The structure of the semi-transparent semi-reflective grating 303 is a uniform grating, and the uniform grating structure comprises any one of the following two types according to different periods:

1. the grating period is 5-20 μm, the duty ratio is 20-80%, the grating order is 10-80, and the grating is etched by common photoetching technology.

2. The grating period is 0.5-5 μm, the duty ratio is 20-80%, the grating order is 1-10 orders, and the grating is formed by etching by an electron beam lithography technology or a holographic lithography technology.

No matter which structure the uniform grating has, the etching depth is 0.1-10 μm.

In other embodiments of the present invention, the material of substrate layer 102 is N-type GaAs.

The thickness of the N-type cladding layer 103 is 0.5-3 μm, the material of the N-type cladding layer 103 is AlGaAs, the weight part of Al is 0.1-0.6, the dopant is silicon, and the doping concentration of the silicon is 1E18-8E18/cm³。

The thickness of the N-type waveguide layer 104 is 0.1-10 μm, the N-type waveguide layer 104 is made of AlGaAs, the weight part of Al is 0.05-0.7, the dopant is silicon, and the doping concentration of the silicon is 1E 16-8E 18/cm³。

The active layer 105 is of a potential barrier/quantum well/potential barrier structure, the active layer is made of AlGaAsP/InAlGaAs/AlGaAsP, the In is 0-0.5 parts by weight, the Al is 0-0.5 parts by weight, the P is 0-0.2 parts by weight, the potential barrier is 1-200 nm thick, the quantum well is 1-20 nm thick, and the light-emitting waveband of the active layer is 700-1200 nm.

The thickness of the P-type waveguide layer 106 is 0.1-10 μm, the P-type waveguide layer 106 is made of AlGaAs, Al is 0.05-0.7 parts by weight, the dopant is carbon, and the doping concentration of the carbon is 1E 16-8E 18/cm³。

The thickness of the P-type cladding layer 107 is0.5-3 μm, the P-type cladding layer 106 is made of AlGaAs, Al 0.1-0.6 weight parts, the dopant is carbon, and the doping concentration of carbon is 1E18-8E18/cm³。

The thickness of the P-type cover layer 108 is 0.1-3 mu m, the material of the P-type cover layer 108 is GaAs, the dopant is carbon, and the doping concentration of the carbon is 1E 18-1E 20/cm³。

The materials of the light amplification region electrode 110 and the P-type gain switch electrode 111 are all alloys formed by any two or more of titanium, platinum, gold, nickel and germanium.

The material of the insulating layer 109 is SiO₂Or Si₃N₄The thickness of the insulating layer 109 is 50nm to 1000 nm.

The working principle of the semiconductor laser is as follows:

the light amplification region 213 is powered up, the material of the pumping active layer generates light gain, the light gain oscillates between the grating region 212 and the front cavity surface in the first laser cavity, and is amplified in the light amplification region 213 to form first wavelength laser (electroluminescence), when the light gain in the first laser cavity is equal to the loss of the device with the grating, a part of the first wavelength laser is output from the front cavity surface, the other part of the first wavelength laser returns to the first laser cavity to oscillate, a part of the first wavelength laser returning to the first laser cavity returns to the first laser cavity to oscillate through the reflection of the semi-transparent semi-reflective grating 303, the other part of the first wavelength laser enters the second laser cavity through the semi-transparent semi-reflective grating 303, and the first wavelength laser reaching the light pumping region 211 directly pumps the material of the active layer 105 to generate light gain.

When the gain switch region 210 is not powered on, the optical gain generated by the first wavelength laser pump is absorbed in the gain switch region 210, and cannot reach the back cavity surface and is reflected to form optical oscillation, and at this time, the second laser cavity is in a closed state.

When the gain switch region 210 is powered up and the optical gain of the gain switch region 210 is equal to the optical loss, the optical gain generated by the first wavelength laser pump can reach the back cavity surface and be totally reflected back to the second laser cavity to form oscillation, and the optical amplification is formed by the first wavelength laser pump, and at this time, the second laser cavity is in an open state.

The light formed by the pumping of the first wavelength laser amplifies photoluminescence from the first wavelength laser. According to the stokes shift principle, the light wave band emitted by the photoluminescence active layer is red-shifted relative to the light absorption wave band, and laser with the second wavelength is excited.

Compared with the traditional semiconductor laser, the pumping mode of the first wavelength laser is electroluminescence, and the pumping mode of the second wavelength laser is photoluminescence, so that the laser belongs to a brand new dual-wavelength semiconductor laser with an electro-optical hybrid pumping mechanism.

Because the pumping modes of the first wavelength laser and the second wavelength laser are different, even if the materials of the active layers of the first laser cavity and the second laser cavity are the same, the difference between the electroluminescent gain waveband and the photoluminescent gain waveband is 10 nm-30 nm, and further the electroluminescent light is red-shifted to excite the second wavelength laser.

When the optical gain in the second laser cavity is equal to the loss of the device with the grating, the laser light with the second wavelength excited in the second laser cavity enters the optical amplification region 213 through the grating region 212, and is output from the front cavity surface after the optical amplification region 213 is optically amplified.

Since the first laser cavity and the second laser cavity share the grating region 212 (i.e. share the half-transparent and half-reflective grating 303), the device loss generated is the same, and when the optical gain in the first laser cavity and the second laser cavity is equal to the device loss, respectively, dual-wavelength lasing occurs, as shown in fig. 3. The semiconductor laser capable of freely switching single-wavelength and double-wavelength lasing only comprises one grating structure, and the whole manufacturing process is simple.

It can be seen from the working principle of the semiconductor laser that when the gain switch region 210 is not opened, the second laser cavity is in the closed state and cannot excite the second wavelength laser, the semiconductor laser only outputs the first wavelength laser, and when the gain switch region 210 is opened, the second laser cavity is in the opened state and excites the second wavelength laser, and the semiconductor laser simultaneously outputs the first wavelength laser and the second wavelength laser.

The semiconductor laser realizes the switching of single and double wavelengths only by means of one on-chip integrated gain switch area, and the size of the semiconductor laser is consistent with that of a chip of the traditional semiconductor laser, so that the semiconductor laser has extremely high integration easiness.

The foregoing details describe the semiconductor laser structure switchable between single and dual wavelengths provided in the embodiments of the present invention, and the embodiments of the present invention further provide a method for manufacturing the semiconductor laser switchable between single and dual wavelengths, corresponding to the semiconductor laser structure switchable between single and dual wavelengths.

Fig. 4 shows a flow chart of a method for manufacturing a single-wavelength and dual-wavelength switchable semiconductor laser provided according to an embodiment of the present invention.

As shown in fig. 4, the method for manufacturing a semiconductor laser device switchable between single and dual wavelengths according to an embodiment of the present invention includes the following steps:

and S1, preparing an epitaxial structure.

A commercial N-type GaAs substrate is selected as a substrate layer, and an N-type cladding layer, an N-type waveguide layer, an active layer, a P-type waveguide layer, a P-type cladding layer and a P-type cover layer are sequentially deposited on the N-type GaAs substrate to form a wafer containing an epitaxial structure.

And S2, etching the epitaxial structure to form a ridge waveguide.

And photoetching the surface of the wafer (namely the surface of the P-type cover layer) by utilizing the photoetching layout to form a ridge waveguide, and removing the mask layer by BOE and cleaning to obtain the wafer containing the ridge waveguide.

And S3, etching the ridge waveguide to form the transflective grating.

And photoetching the surface of the wafer (or the surface of the P-type cover layer) containing the ridge waveguide by utilizing a photoetching layout to form a semi-transparent semi-reflective grating, and removing a mask layer by BOE (Brillouin etching) and cleaning to obtain the wafer containing the ridge waveguide and the grating.

S4, preparing a P-type electrode layer on the epitaxial structure at a position avoiding the semi-transparent semi-reflective grating; the P-type electrode layer comprises gain switch area electrodes and light amplification area electrodes distributed on two sides of the semi-transparent semi-reflective grating.

The P-type electrode layer further includes an insulating layer located below the gain switching region electrode and the light amplification region electrode and above the P-type cap layer.

Step S4 specifically includes the following steps:

s401: growing an insulating material on the surface of the P-type cover layer to form an insulating layer;

s402: photoetching is carried out on the surface of the insulating layer by utilizing a photoetching layout to form mask patterns of the gain switch area electrode and the light amplification area electrode;

s403: p-type electrodes are grown on the surface of the insulating layer in a metal film evaporation apparatus, and a metal lift-off process (lift-off) is performed using the mask pattern formed in step 402 to prepare the gain switch area electrodes and the amplification area electrodes.

S5, thinning, polishing and cleaning the substrate layer, sputtering an N-type electrode layer on the substrate layer, and carrying out annealing process on the wafer to form the ohm-mode contact.

After step S5, the method for manufacturing a semiconductor laser device switchable between single and dual wavelengths further includes the steps of:

and S6, cleaving the wafer into bars, plating a high-reflection film on the back cavity surface, and cleaving the bars into chips.

Thus, the preparation of the semiconductor laser is completed.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

The above embodiments of the present invention should not be construed as limiting the scope of the present invention. Any other corresponding changes and modifications made according to the technical idea of the present invention should be included in the protection scope of the claims of the present invention.