A 2μm band antimonide dual-wavelength narrow-linewidth laser

Abstract

A 2μm band antimonide dual-wavelength narrow-linewidth laser is disclosed. This invention relates to the field of semiconductor laser technology, specifically to a 2μm band antimonide dual-wavelength narrow-linewidth laser. The invention employs a thin barrier of 1nm~2nm to separate two different quantum wells, obtaining a tunneling-coupled asymmetric quantum well structure, and then achieves dual-wavelength output through electronic transitions. The laser includes: a laser gain region and a composite DBR grating region; the laser gain region includes: a substrate, a buffer layer, a lower confinement layer, a lower waveguide layer, a tunneling-coupled asymmetric quantum well active region, an upper waveguide layer, an upper confinement layer, and a contact layer; the tunneling-coupled asymmetric quantum well active region includes: a first potential well layer, a barrier layer, and a second potential well layer; the composite DBR grating region includes: a DBR grating with a period of T1 on the ridge waveguide and lateral DBR gratings with a period of T2 on both sides of the ridge waveguide.

Description

Technical Field

[0001] This invention relates to the field of semiconductor laser technology, and specifically to a 2μm band antimonide dual-wavelength narrow-linewidth laser. Background Technology

[0002] The 2μm band is an important atmospheric window, containing many important characteristic spectral lines of gas molecules. A strong absorption line exists in the 2.0–2.052 μm band. , as well as Absorption characteristics are also present in this band. Laser spectroscopy gas detection systems can achieve accurate gas concentration detection and have a wide range of applications. In the safety field, they are used for online monitoring of hazardous gas leaks; in the environmental protection field, for monitoring pollutant gas emissions; in the industrial control field, for assessing whether emissions meet standards; and in the military field, for detecting toxic gases in biological and chemical defense units. Therefore, the 2μm band is one of the important light sources for trace gas detection technology and is widely used in gas detection technologies such as tunable diode laser absorption spectroscopy (TDLAS) and cavity ring-down laser absorption spectroscopy (CRDS).

[0003] Narrow-linewidth semiconductor lasers, with their advantages of high electro-optical conversion efficiency, small size, and long lifespan, have become core devices in optical communication and optoelectronic sensing. In the gas detection market, currently mature commercial TDLAS instruments are limited to the near-infrared window: 1657 nm lasers are used... Detection, 1567 nm laser used Detection. However, , The absorption coefficient in the mid-infrared band is 2–3 orders of magnitude higher than that in the near-infrared band, with less spectral overlap, low cross-interference, and extremely high resolution. Existing instruments, lacking an engineerable narrow-linewidth mid-infrared light source, have to "abandon" this strongest absorption region, resulting in detection limits, selectivity, and anti-interference capabilities all remaining at the ppm level, leading to significant low-concentration leakage and trace amounts in complex backgrounds. / The signal is systematically missed, forming a "mid-infrared blind zone" that current technology cannot cover.

[0004] Currently, laser spectrometers for gas detection use a single (tunable) wavelength light source, and traditional DFB / DBR lasers have a limited tuning range of only a few nanometers (the characteristic absorption lines of a gas are typically distributed within a very narrow, specific wavelength range). An instrument using a single DFB laser can usually only cover one target gas (such as...). One or more adjacent spectral lines cannot be used to simultaneously measure other gases with significantly different wavelengths (e.g., simultaneously measuring...). and (), which is difficult to cover the needs of multi-gas detection.

[0005] To achieve simultaneous detection of multiple gases (multiple components), the traditional approach is to equip each gas with a separate laser, using optical beam combining or switching. This directly results in a complex, expensive, bulky, and power-consuming system.

[0006] Chinese invention patent CN103078252A, entitled "Dual-wavelength antimonide strained quantum well semiconductor laser and its fabrication method," proposes a technical solution for a dual-wavelength antimonide semiconductor laser. This solution involves vertically stacking the active regions of two lasers with different wavelengths through a tunneled pn junction. The two active regions then emit photons at different frequencies through recombination emission, achieving dual-wavelength laser emission. This patent's method of achieving dual-wavelength laser emission via a tunneled pn junction requires a high carrier doping concentration in the pn junction, typically around 10⁻⁶. 19 cm -3 The above places extremely high demands on the epitaxy of antimonide laser materials, making it very difficult to achieve. Summary of the Invention

[0007] To address the aforementioned problems, the purpose of this invention is to propose a 2μm band antimonide dual-wavelength narrow-linewidth laser. A thin barrier of 1.0nm~2.0nm is used to separate two different quantum wells, resulting in a tunneling-coupled asymmetric quantum well structure. Dual-wavelength output is then achieved through electronic transitions.

[0008] The method includes the following steps:

[0009] The laser includes: a laser gain region and a composite DBR grating region;

[0010] The laser gain region and the composite DBR grating region are made of the same laser epitaxial material in the longitudinal direction, and the laser gain region and the composite DBR grating region are adjacent in the horizontal light output direction.

[0011] The laser gain region includes: substrate, buffer layer, lower confinement layer, lower waveguide layer, tunneling coupled asymmetric quantum well active region, upper waveguide layer, upper confinement layer, and contact layer;

[0012] The active region of the tunneling-coupled asymmetric quantum well includes: A tunneling-coupled asymmetric quantum well structure with one cycle;

[0013] Tunneling coupled asymmetric quantum well structures include: First potential well layer Barrier layer and Second potential well layer;

[0014] The composite DBR grating region includes: a DBR grating with a period of T1 on the ridge waveguide and lateral DBR gratings with a period of T2 on both sides of the ridge waveguide.

[0015] The longitudinal direction is the direction in which the substrate penetrates to the contact layer.

[0016] further, The thickness of the barrier layer ranges from 1.0 nm to 2.0 nm.

[0017] The thickness of the first potential well layer ranges from 6 nm to 10 nm.

[0018] The thickness range of the second potential well layer is 8nm~12nm;

[0019] The thickness of the first potential well layer is... The second potential well layer is only 2 nm thick.

[0020] further, , , , , as well as All of these represent the components of an element. ; ; ; ; ; .

[0021] Furthermore, the electronic state energy levels of the tunnel-coupled asymmetric quantum well structure split, resulting in electronic state energy level e1 and electronic state energy level e2;

[0022] e1 and e2 transition from the conduction band to the valence band hole hh1, respectively, resulting in two photons of different frequencies;

[0023] The energy difference between e1 and e2 ranges from 1 THz to 5 THz.

[0024] Furthermore, the substrate is made of N-type GaSb material; the buffer layer is also made of N-type GaSb material.

[0025] Furthermore, the lower confinement layer adopts N-type Al 0.5 Ga 0.5 As 0.04 Sb 0.96 The material has a thickness range of 1000nm to 1500nm.

[0026] The lower waveguide layer uses N-type Al 0.25 Ga 0.75 As 0.03 Sb 0.97 Materials with a thickness range of 200nm~300nm;

[0027] The upper waveguide layer uses P-type Al0.25 Ga 0.75 As 0.03 Sb 0.97 Materials with a thickness range of 200nm~300nm;

[0028] The upper confinement layer adopts P-type Al 0.5 Ga 0.5 As 0.04 Sb 0.96 The material has a thickness range of 1000nm to 1500nm.

[0029] The contact layer is made of P-type GaSb material with a thickness ranging from 200nm to 300nm.

[0030] Furthermore, both the DBR grating with a period of T1 on the ridge waveguide and the lateral DBR gratings with a period of T2 on both sides of the ridge waveguide are second-order gratings.

[0031] , Indicates the current raster order. This represents the output wavelength of a DBR grating with period T1 on the ridge waveguide. Indicates the effective refractive index of the upper confinement layer;

[0032] The calculation method for T2 is the same as that for T1.

[0033] Furthermore, the fabrication method of the 2μm band antimonide semiconductor laser is as follows:

[0034] S1. Based on the output wavelength of the target laser, set the thickness, period, and composition of each component in the laser gain region;

[0035] S2. According to the settings in step S1, a buffer layer, a lower confinement layer, a lower waveguide layer, a tunneling coupled asymmetric quantum well active region, an upper waveguide layer, an upper confinement layer, and a contact layer are sequentially epitaxially grown on the substrate using a molecular beam epitaxy device to obtain a full-structure epitaxial wafer of an antimonide laser.

[0036] S3. The epitaxial wafer of the antimonide laser is sequentially photolithographically and etched to obtain a strip ridge waveguide.

[0037] S5. Electron beam lithography and dry etching are performed sequentially on the strip ridge waveguide to obtain the grating structure of the composite DBR grating region. The dry etching range is the upper confinement layer and the contact layer.

[0038] S6. On the strip ridge waveguide after step S5, an insulating layer is deposited using the PECVD method, and then the insulating layer is etched to obtain the P-side electrode window.

[0039] S7. The P-side electrode is grown using the magnetron sputtering method of Ti / Pt / Au.

[0040] S8. Perform photolithography and etching on the cleavage grooves, and thin and polish the back side of the substrate to 100μm~120μm;

[0041] S9. Thin and polish the back side of the substrate to 100μm~120μm;

[0042] S9. The N-side electrode was grown using magnetron sputtering of Ni / AuGe / Au.

[0043] S10. Rapid annealing completes the ohmic contact, followed by cleavage and sintering to complete the encapsulation and obtain the laser.

[0044] The beneficial effects of the method described in this invention are as follows:

[0045] (1) The laser described in this invention uses a thin barrier of 1.0 nm to 2.0 nm to separate two different quantum wells to obtain a tunneling coupled asymmetric quantum well structure. Since the barrier is thin enough, the electronic state will tunnel coupled to form a split energy level electronic state level e1 and electronic state level e2, forming a three-level system (e2 transitions to e1, e2 transitions to the valence band hole and e1 transitions to the valence band hole). During the process of the two electronic state levels e1 and e2 in the conduction band transitioning to the valence band hole level hh1, photons of two frequencies are emitted, that is, dual-wavelength output is achieved. Since the carrier recombination form is an interband transition, the method described in this invention also has the performance of working at room temperature and low threshold current.

[0046] (2) By adjusting the barrier thickness and composition and the thickness and composition of the well layer (the barrier thickness and composition and the thickness and composition of the well layer can directly affect the carrier energy level distribution, the electronic state tunneling coupling obtains the split electronic state energy level, and the energy difference generated after the electronic state transition is positively correlated with the frequency of the emitted photon), the laser of the present invention can output dual-wavelength laser in the 2μm band, which can realize the simultaneous detection of two gases.

[0047] (3) The laser described in this invention can also precisely control the energy difference between the two split energy levels (e1 and e2) by adjusting the barrier thickness and material composition. That is, a controlled energy level spacing is formed between the two electronic states (e2 transitions to e1), and the energy difference ranges from 1THz to 5THz. Attached Figure Description

[0048] Figure 1 This is a schematic diagram of the laser material described in this invention;

[0049] Figure 2This is a schematic diagram of electronic transitions in the tunneling coupled asymmetric quantum well structure described in this invention;

[0050] Figure 3 This is a three-dimensional schematic diagram of the laser described in this aspect;

[0051] 1-Laser gain region, 2-Composite DBR grating region, 11-Substrate, 12-Buffer layer, 13-Lower confinement layer, 14-Lower waveguide layer, 15-Tunneling coupled asymmetric quantum well active region, 16-Upper waveguide layer, 17-Upper confinement layer, 18-Contact layer, 151- First potential well layer, 152- Barrier layer, 153- The second potential well layer, 21-a DBR grating with period T1 on the ridge waveguide, and 22-lateral DBR gratings with period T2 on both sides of the ridge waveguide. Detailed Implementation

[0052] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0053] This embodiment provides a 2μm band antimonide dual-wavelength narrow linewidth laser with GaSb as the substrate. The laser includes: a laser gain region 1 and a composite DBR grating region 2.

[0054] like Figure 1 As shown, the laser gain region 1 includes: a substrate 11, a buffer layer 12, a lower confinement layer 13, a lower waveguide layer 14, a tunneling coupled asymmetric quantum well active region 15, an upper waveguide layer 16, an upper confinement layer 17, and a contact layer 18.

[0055] The active region 15 of the tunneling-coupled asymmetric quantum well includes: In this embodiment, a tunneling-coupled asymmetric quantum well structure with one period is described. ;

[0056] Tunneling coupled asymmetric quantum well structures include: First potential well layer 151 Barrier layer 152 and Second potential well layer 153;

[0057] In this embodiment, the composition and thickness of the tunnel-coupled asymmetric quantum well structure are selected as follows:

[0058] The thickness of the first potential well layer 151 is 6 nm;

[0059] The thickness of barrier layer 152 is 1.2 nm;

[0060] The thickness of the second potential well layer 153 is 8 nm;

[0061] The thickness of the first potential well layer 151 is... The second potential well layer is 153 with a thickness of less than 2nm.

[0062] In this embodiment, the thicknesses of the lower limiting layer 13, lower waveguide layer 14, upper waveguide layer 16, upper limiting layer 17, and contact layer 18 are selected as follows (those skilled in the art can set them according to actual conditions):

[0063] The lower confinement layer 13 adopts N-type Al 0.5 Ga 0.5 As 0.04 Sb 0.96 Material, thickness: 1500nm;

[0064] Lower waveguide layer 14 adopts N-type Al 0.25 Ga 0.75 As 0.03 Sb 0.97 Material, thickness: 300nm;

[0065] Upper waveguide layer 16 adopts P-type Al 0.25 Ga 0.75 As 0.03 Sb 0.97 Material, thickness: 300nm;

[0066] Upper confinement layer 17 adopts P-type Al 0.5 Ga 0.5 As 0.04 Sb 0.96 Material, thickness: 1500nm;

[0067] Contact layer 18 is made of P-type GaSb material with a thickness of 300 nm.

[0068] like Figure 3 As shown, the laser gain region 1 and the composite DBR grating region 2 are made of the same laser epitaxial material in the longitudinal direction, and the laser gain region 1 and the composite DBR grating region 2 are adjacent to each other in the horizontal light output direction.

[0069] The longitudinal direction is the direction in which the substrate 11 extends to the contact layer 18.

[0070] The composite DBR grating region 2 includes: a DBR grating 21 with a period of T1 on the ridge waveguide and lateral DBR gratings 22 with a period of T2 on both sides of the ridge waveguide;

[0071] Both the DBR grating 21 with a period of T1 on the ridge waveguide and the lateral DBR gratings 22 with a period of T2 on both sides of the ridge waveguide are second-order gratings.

[0072] The output light wavelengths of the DBR grating 21 with period T1 on the ridge waveguide and the lateral DBR gratings 22 with period T2 on both sides of the ridge waveguide compress the output linewidth, making the output linewidth narrow.

[0073] , Indicates the current raster order. This represents the output wavelength of the DBR grating 21 with period T1 on the ridge waveguide. This represents the effective refractive index of the upper confinement layer 17. In this example, , , ;

[0074] The calculation method for T2 is the same as that for T1. In this embodiment, the output wavelength of the lateral DBR grating 22 with a period of T2 on both sides of the ridge waveguide is... .

[0075] like Figure 2 As shown, the tunnel-coupled asymmetric quantum well structure undergoes electronic state level splitting to obtain electronic state level e1 and electronic state level e2;

[0076] e1 and e2 transition from the conduction band to the valence band hole hh1, respectively, resulting in two frequency photons hv1 and hv2;

[0077] The energy difference between e1 and e2 ranges from 1 THz to 5 THz.

[0078] According to this embodiment, Depletion layer 152 thickness and composition and well layer ( First potential well layer 151 and By adjusting the thickness and composition of the second potential well layer (153), the laser of the present invention can output lasers with wavelengths of 2.1 μm and 2.3 μm.

[0079] Example 2

[0080] This embodiment provides a method for fabricating a 2μm band antimonide semiconductor laser:

[0081] Step 1: Design the laser structure according to the output wavelength of the target laser, that is, set the thickness, period and composition of each component (substrate 11, buffer layer 12, lower confinement layer 13, lower waveguide layer 14, tunneling coupled asymmetric quantum well active region 15, upper waveguide layer 16, upper confinement layer 17 and contact layer 18) in the laser gain region 1.

[0082] Step 2: Based on the laser structure designed in Step 1, a buffer layer 12, a lower confinement layer 13, a lower waveguide layer 14, a tunneling coupled asymmetric quantum well active region 15, an upper waveguide layer 16, an upper confinement layer 17, and a contact layer 18 are sequentially epitaxially grown on an (N-type GaSb) substrate 11 using a molecular beam epitaxy device to obtain a full-structure epitaxial wafer of an antimonide laser.

[0083] An (N-type GaSb) buffer layer 12 is formed on an (N-type GaSb) substrate 11, and the doping element is Te with a doping concentration of: ;

[0084] (N-type Al) 0.5 Ga 0.5 As 0.04 Sb 0.96 The lower confinement layer 13 uses Te as the doping source, and the doping concentration is: The epitaxial layer is on the (N-type GaSb) buffer layer 12;

[0085] (N-type Al) 0.25 Ga 0.75 As 0.03 Sb 0.97 The lower waveguide layer 14 uses Te as the doping source, and the doping concentration is: , extension in (N-type Al) 0.5 Ga 0.5 As 0.04 Sb 0.96 Lower restriction layer 13;

[0086] The active region of the tunneling-coupled asymmetric quantum well is epitaxially extended in (N-type Al) 0.25 Ga 0.75 As 0.03 Sb 0.97 Lower waveguide layer 14;

[0087] (P-type Al) 0.25 Ga 0.75 As 0.03 Sb 0.97 The upper waveguide layer 16 uses Be as the doping source, and the doping concentration is: The epitaxial layer is located on the active region 15 of the tunnel-coupled asymmetric quantum well;

[0088] (P-type Al) 0.5 Ga 0.5 As 0.04 Sb 0.96 The upper confinement layer 17 uses Be as the doping source, and the doping concentration is: Extensional in (P-type Al) 0.25 Ga 0.75 As 0.03 Sb 0.97Upper waveguide layer 16;

[0089] (P-type GaSb) Contact layer 18 uses Be as the doping source, and the doping concentration is: Extensional in (P-type Al) 0.5 Ga 0.5 As 0.04 Sb 0.96 Upper restriction layer 17;

[0090] Step 3: Using the full-structure epitaxial wafer of the antimony laser obtained in Step 2, the laser fabrication process is carried out. The specific process steps are as follows:

[0091] S1. Epitaxial wafer cleaning: The surface of the epitaxial wafer is purged with nitrogen to remove solid impurity particles. Then, acetone, ethanol, and deionized water are used respectively for 5 minutes in a water bath. Finally, the surface of the epitaxial wafer is dried with nitrogen.

[0092] S2. Oxide surface treatment with dilute hydrochloric acid: Immerse the epitaxial wafer in dilute hydrochloric acid with a concentration of HCl:H2O=1:10 for 30 seconds to remove surface oxides.

[0093] S3. The first photolithography step completes the ridge waveguide photolithography, resulting in the ridge waveguide mesa: a strip waveguide pattern is prepared using positive photoresist AZ5214, the spin coating speed is 4000 r / min, the resist thickness on the epitaxial wafer surface is ~1.8 μm, pre-baking at 95℃ for 90s, UV exposure for 4.5s, development for 20s, and hardening at 120℃ for 120s.

[0094] S4. Etching of the strip ridge waveguide is completed using either dry or wet methods to obtain the strip ridge waveguide: The strip ridge waveguide is etched at a wavelength of 200nm~300nm using a phosphoric acid-based etching solution (sodium hydrogen tartrate: deionized: hydrogen peroxide: phosphoric acid = 5g: 90ml: 30ml: 30ml) or a chlorine-based dry etching gas (BCl3 / Cl2 / Ar = 20sccm / 5sccm / 20sccm, 2mTorr).

[0095] S5. Electron beam lithography (second edition of lithography) Composite DBR grating region 2 grating pattern: The composite DBR grating region 2 of the strip ridge waveguide is lithographically etched using electron beam lithography. The DBR grating pattern with period T1 is lithographically etched on the strip ridge waveguide, and the DBR grating patterns with period T2 are lithographically etched on both sides of the strip ridge waveguide.

[0096] S6. Dry etching of composite grating region grating structure: GaSb-based material is etched using chlorine-based dry etching gas (BCl3 / Cl2 / Ar=20sccm / 5sccm / 20sccm, 2mTorr) to an etching depth of 50nm~100nm above the upper confinement layer.

[0097] S7, PECVD deposition of insulating layer: For the strip ridge waveguide after the above S1 to S6 processes, the surface of the epitaxial wafer is baked at 120℃ for 30 minutes, and then a Si3N4 layer with a thickness of ~300nm is deposited by PECVD to serve as the insulating layer.

[0098] S8. Use wet or dry etching of the insulating dielectric layer material to complete the P-side open electrode window, which is located on the strip ridge waveguide of the laser gain region 1.

[0099] S9. The P-side electrode was grown by magnetron sputtering of Ti / Pt / Au. The thicknesses of Ti / Pt / Au deposited by magnetron sputtering equipment were 50nm / 50nm / 300nm, respectively.

[0100] S10, the third version of photolithography completes the photolithography and etching of the cleavage grooves, achieving the effect of clearly marking the chip cutting point with the help of the cleavage groove pattern parallel to the cleavage surface.

[0101] S11, Thinning and polishing the back side of substrate 11: The back side of (GaSb) substrate 11 is mechanically thinned to 100μm~120μm using an aqueous solution of aluminum oxide, and then polished to a bright surface on a polishing cloth with a chemical polishing solution.

[0102] S12, Magnetron sputtering N-face electrode: Ni / AuGe / Au electrodes with thicknesses of 5nm / 50nm / 300nm were deposited using magnetron sputtering equipment.

[0103] S13, N-side electrode rapid annealing to complete ohmic contact: In a nitrogen atmosphere, substrate 11 is rapidly heated to 380°C, held for 120s, and then rapidly cooled to room temperature. After completing the rapid thermal annealing process, a 50nm~300nm Au film is sputtered.

[0104] S14. Cleavage to obtain Bar strips and deposit cavity films: Using an electron beam evaporation device, an antireflective film with a reflectivity of less than 5% is deposited on the front cavity surface, and an antireflective film with a reflectivity of greater than 95% is deposited on the rear cavity surface.

[0105] S15, cleavage the Bar strip to obtain a single tube core.

[0106] S16. Sintering and Packaging: The device is packaged using Cmount or COS sintering to obtain the laser described in this invention.

[0107] This invention changes The thickness of the barrier layer 152 can be adjusted to regulate the energy difference between electronic state levels e1 and e2, thereby obtaining a dual-wavelength antimonide laser with other wavelengths in the 2μm band.

[0108] Example 3

[0109] This embodiment is a further limitation of Embodiment 1.

[0110] In this embodiment, The thickness of the barrier layer 152 is 1.0 nm, and the rest of the settings are the same as in Example 1.

[0111] Example 4

[0112] This embodiment is a further limitation of Embodiment 1.

[0113] In this embodiment, The thickness of the barrier layer 152 is 1.1 nm, and the rest of the settings are the same as in Example 1.

[0114] Example 5

[0115] This embodiment is a further limitation of Embodiment 1.

[0116] In this embodiment, The thickness of the barrier layer 152 is 1.3 nm, and the rest of the settings are the same as in Example 1.

[0117] Example 6

[0118] This embodiment is a further limitation of Embodiment 1.

[0119] In this embodiment, The thickness of the barrier layer 152 is 1.4 nm, and the rest of the settings are the same as in Example 1.

[0120] Example 7

[0121] This embodiment is a further limitation of Embodiment 1.

[0122] In this embodiment, The thickness of the barrier layer 152 is 1.5 nm, and the rest of the settings are the same as in Example 1.

[0123] Example 8

[0124] This embodiment is a further limitation of Embodiment 1.

[0125] In this embodiment, The thickness of the barrier layer 152 is 1.6 nm, and the rest of the settings are the same as in Example 1.

[0126] Example 9

[0127] This embodiment is a further limitation of Embodiment 1.

[0128] In this embodiment, The thickness of the barrier layer 152 is 1.7 nm, and the rest of the settings are the same as in Example 1.

[0129] Example 10

[0130] This embodiment is a further limitation of embodiment 1.8.

[0131] In this embodiment, The thickness of the barrier layer 152 is 1 nm, and the rest of the settings are the same as in Example 1.

[0132] Example 11

[0133] This embodiment is a further limitation of Embodiment 1.

[0134] In this embodiment, The thickness of the barrier layer 152 is 1.8 nm, and the rest of the settings are the same as in Example 1.

[0135] Example 12

[0136] This embodiment is a further limitation of Embodiment 1.

[0137] In this embodiment, The thickness of the barrier layer 152 is 1.9 nm, and the rest of the settings are the same as in Example 1.

[0138] Example 13

[0139] This embodiment is a further limitation of Embodiment 1.

[0140] In this embodiment, The thickness of the barrier layer 152 is 2.0 nm, and the rest of the settings are the same as in Example 1.

[0141] The above description is only a preferred embodiment of the present invention. It should be noted that the scope of protection of the present invention is not limited thereto. For those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A 2 μm waveband antimonide semiconductor laser, characterised in that, The laser comprises a laser gain region (1) and a composite DBR grating region (2); The laser gain region (1) and the composite DBR grating region (2) are the same laser epitaxial material in the longitudinal direction, and the laser gain region (1) is adjacent to the composite DBR grating region (2) in the horizontal light-emitting direction; The laser gain region (1) comprises a substrate (11), a buffer layer (12), a lower confinement layer (13), a lower waveguide layer (14), a tunnel-coupled asymmetric quantum well active region (15), an upper waveguide layer (16), an upper confinement layer (17), and a contact layer (18); The tunneling coupled asymmetric quantum well active region (15) includes: a tunneling coupled asymmetric quantum well structure of one period; The tunneling coupled asymmetric quantum well structure comprises: a first potential well layer (151), a barrier layer (152), and a second potential well layer (153). The composite DBR grating region (2) comprises a ridge waveguide upper DBR grating (21) with a period T1 and ridge waveguide side DBR gratings (22) on both sides with a period T2; The longitudinal direction is the direction of the substrate (11) penetrating through to the contact layer (18).

2. The 2 μm band antimonide semiconductor laser according to claim 1, wherein, The thickness of the barrier layer (152) ranges from 1.0 nm to 2.0 nm. The first potential well layer (151) has a thickness in the range of 6 nm to 10 nm. Second potential well layer (153) thickness range: 8nm~12nm; The first potential well layer (151) thickness is greater than The second potential well layer (153) thickness is less than 2 nm.

3. The 2 μm band antimonide semiconductor laser according to claim 2, wherein, , , , , and denote the components of an element, ; ; ; ; ; .

4. The 2-micron band antimonide semiconductor laser of claim 3, wherein The tunnel-coupled asymmetric quantum well structure splits the electronic state energy level to obtain an electronic state energy level e1 and an electronic state energy level e2; e1 and e2 respectively transition from the conduction band to the valence band hole hh1 to obtain two frequency photons; The energy difference between e1 and e2 ranges from 1 THz to 5 THz.

5. The 2 μm wavelength band antimonide semiconductor laser according to claim 4, wherein, The substrate (11) is made of N-type GaSb material; the buffer layer (12) is made of N-type GaSb material.

6. The 2-micron band antimonide semiconductor laser of claim 4, wherein The lower confinement layer (13) is made of N-type Al 0.5 Ga 0.5 As 0.04 Sb 0.96 material, with a thickness ranging from 1000 nm to 1500 nm; The lower waveguide layer (14) is made of N-type Al 0.25 Ga 0.75 As 0.03 Sb 0.97 material, with a thickness ranging from 200 nm to 300 nm; The upper waveguide layer (16) is made of P-type Al 0.25 Ga 0.75 As 0.03 Sb 0.97 material, with a thickness ranging from 200 nm to 300 nm; The upper confinement layer (17) uses P-type Al 0.5 Ga 0.5 As 0.04 Sb 0.96 material, thickness range: 1000nm~1500nm; The contact layer (18) is made of P-type GaSb material, and the thickness ranges from 200 nm to 300 nm.

7. The 2-micron band antimonide semiconductor laser of claim 6, wherein The ridge waveguide upper DBR grating (21) with a period T1 and the ridge waveguide side DBR gratings (22) on both sides with a period T2 are both second-order gratings; , represents the current grating order, represents the exit light wavelength of the DBR grating (21) on the ridge waveguide with a period of T1, represents the effective refractive index of the upper cladding layer (17); T2 and T1 are calculated in the same way.

8. The 2 μm wavelength band antimonide semiconductor laser according to claim 7, wherein, The preparation method of the 2-micron band antimonide semiconductor laser is as follows: S1. According to the target laser output wavelength, set the thickness, period, and composition of each component in the laser gain region (1); S2. According to the setting of step S1, use a molecular beam epitaxy device to epitaxially grow the buffer layer (12), the lower confinement layer (13), the lower waveguide layer (14), the tunnel-coupled asymmetric quantum well active region (15), the upper waveguide layer (16), the upper confinement layer (17), and the contact layer (18) on the substrate (11) in sequence to obtain an antimonide laser full-structure epitaxial wafer; S3. Perform photolithography and etching on the antimonide laser full-structure epitaxial wafer in sequence to obtain a strip-shaped ridge waveguide; S5. Perform electron beam lithography and dry etching on the strip-shaped ridge waveguide in sequence to obtain the grating structure of the composite DBR grating region (2), and the dry etching range is the upper confinement layer (17) and the contact layer (18); S6. On the strip-shaped ridge waveguide after step S5, deposit an insulating layer by PECVD method, and then etch the insulating layer to obtain a P-face electrode window; S7. Complete P-face electrode growth by using a magnetron sputtering Ti / Pt / Au method. S8, photoetching and etching are performed on the cleavage groove, and the back of the substrate (11) is thinned and polished to 100-120 μm; S9, the growth of N-face electrode is completed by magnetron sputtering of Ni / AuGe / Au; S10, ohmic contact is completed by rapid annealing, and packaging is completed by cleavage and sintering, thereby obtaining a laser.

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