A two-phase array VCSEL laser beam control device and preparation method

Abstract

The present invention discloses a two-phase array VCSEL laser beam control device and a preparation method thereof, comprising: a VCSEL inner cavity layer and a first liquid crystal outer cavity layer; the VCSEL inner cavity layer is a VCSEL epitaxial structure grown on a wafer, and light-emitting units arranged in a certain periodicity are prepared on the VCSEL epitaxial structure; the first liquid crystal outer cavity layer is closely attached to the surface of the light-emitting area of ​​the VCSEL inner cavity layer as a reflective layer. The present invention adheres a liquid crystal layer on the basis of a VCSEL array laser, changes the refractive index value of the liquid crystal layer by adjusting the voltage, and then adjusts the phase difference and beam direction between the light-emitting units, solves the problem of poor beam quality of traditional VCSEL array lasers, and realizes high beam quality in-phase mode coherent array laser output.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor laser technology, and in particular to a two-phase array VCSEL laser beam control device and a preparation method thereof. Background Art

[0002] Compared with edge-emitting semiconductor lasers, vertical-cavity surface-emitting lasers (VCSELs) are widely used in laser printing, 3D sensing, optical communications, and optical storage due to their advantages such as good monochromaticity, single longitudinal-mode lasing, low threshold current, low power consumption, easy two-dimensional integration, circular light spot, easy coupling with optical fibers, “on-wafer” detection, and low cost.

[0003] With the continuous development of science and technology, higher requirements are placed on the beam quality of the VCSEL array output laser. It is often required that the VCSEL array beam have high power, narrow linewidth, high beam quality, and also achieve wavelength tunability, wave number control, and precise polarization control. Existing VCSEL lasers are difficult to meet this requirement. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a two-phase array VCSEL laser beam control device and a preparation method, which can solve the problems of poor VCSEL array laser beam quality and low power, and realize beam orientation and high beam quality in-phase mode coherent array laser output.

[0005] The present invention discloses a two-phase array VCSEL laser beam control device, comprising: a VCSEL inner cavity layer and a first liquid crystal outer cavity layer;

[0006] The VCSEL inner cavity layer is a VCSEL epitaxial structure grown on a wafer, and light-emitting units arranged in a certain periodicity are prepared on the VCSEL epitaxial structure;

[0007] The first liquid crystal outer cavity layer is closely attached to the surface of the light emitting area of ​​the VCSEL inner cavity layer as a reflective layer.

[0008] As a further improvement of the present invention, the first liquid crystal external cavity layer can be addressed point by point to change the refractive index to perform optical feedback on the light-emitting array, thereby realizing mutual injection locking of the light-emitting units.

[0009] As a further improvement of the present invention, the first liquid crystal external cavity layer serves as a phase control layer, which can correspondingly adjust the phase at the position of each VCSEL light-emitting unit, control the overall phase of the VCSEL laser array, realize the selection of the same-phase mode, and obtain VCSEL coherent laser.

[0010] As a further improvement of the present invention, it also includes: a second liquid crystal outer cavity layer;

[0011] The second liquid crystal external cavity layer is closely attached to the top of the first liquid crystal external cavity layer.

[0012] As a further improvement of the present invention, the reflectivity of the P-type DBR layer is 50%-99%, which cannot reach the laser light emission threshold.

[0013] As a further improvement of the present invention, the second liquid crystal external cavity layer introduces a refractive index gradient difference along the beam path between the second liquid crystal external cavity layer and the first liquid crystal external cavity layer at the corresponding light-emitting unit to control the light field phase and change the emission direction of the laser beam to achieve lens-free focusing.

[0014] As a further improvement of the present invention, a P electrode and an N electrode are formed on the VCSEL epitaxial structure, and the VCSEL epitaxial structure is an array-type top-emitting or bottom-emitting structure, including an N-type DBR layer, an N-type waveguide layer, a semiconductor multi-quantum well layer, a P-type waveguide layer, an oxidation restriction layer and a P-type DBR layer grown sequentially on the substrate layer.

[0015] As a further improvement of the present invention,

[0016] When the VCSEL epitaxial structure is an array-type top emission structure, the first liquid crystal external cavity layer is formed on the surface of the central light-emitting region of the P-type DBR layer, the P electrode is formed by sputtering on a portion of the surface, a passivation layer is deposited on the remaining portion of the surface, and the N electrode is formed on the bottom surface of the substrate layer;

[0017] When the VCSEL epitaxial structure is an array-type bottom emission structure, the P-electrode is formed by sputtering in the central area of ​​the P-type DBR layer, and a passivation layer is deposited on the remaining surface; the first liquid crystal external cavity layer is formed on the surface of the central light-emitting area of ​​the bottom surface of the substrate layer, and the N-electrode is formed on the remaining surface by sputtering.

[0018] As a further improvement of the present invention,

[0019] When the VCSEL epitaxial structure is an array-type top emission structure, the first liquid crystal external cavity layer includes a liquid crystal layer cathode, a liquid crystal layer, a liquid crystal layer anode and glass arranged in sequence from the surface of the P-type DBR layer, an alignment film is arranged between the liquid crystal layer cathode and the liquid crystal layer and between the liquid crystal layer anode and the liquid crystal layer, and a spacer layer is arranged between the liquid crystal layer anode and the P electrode;

[0020] When the VCSEL epitaxial structure is an array-type bottom emission structure, the first liquid crystal external cavity layer includes a liquid crystal layer cathode, a liquid crystal layer, a liquid crystal layer anode and glass arranged in sequence from the surface of the substrate layer, an orientation film is provided between the liquid crystal layer cathode and the liquid crystal layer and between the liquid crystal layer anode and the liquid crystal layer, and a pad spacer layer is provided between the liquid crystal layer anode and the N electrode.

[0021] The present invention also discloses a method for preparing a two-phase array VCSEL laser beam control device, comprising:

[0022] Growing a VCSEL epitaxial structure, wherein the VCSEL epitaxial structure comprises an N-type DBR layer, an N-type waveguide layer, a semiconductor multi-quantum well layer, a P-type waveguide layer, an oxidation restriction layer and a P-type DBR layer sequentially grown on the substrate layer;

[0023] A mesa is formed on the VCSEL epitaxial structure to expose the oxidation restriction layer, and an oxidation hole is formed on the oxidation restriction layer;

[0024] Depositing a passivation layer on the mesa structure and etching out the laser light emitting area to make a P electrode and an N electrode;

[0025] A first liquid crystal external cavity layer is formed on the top or bottom laser light emitting area;

[0026] Preparing a second liquid crystal external cavity layer on the first liquid crystal external cavity layer;

[0027] Decomposition package.

[0028] As a further improvement of the present invention, the method of making the first liquid crystal external cavity layer includes:

[0029] Depositing a liquid crystal layer cathode on the surface of the light emitting area;

[0030] Spin coating an alignment film on the cathode of the liquid crystal layer;

[0031] After photolithography, a spacer layer is spin-coated on the P electrode or the N electrode to form a groove for injecting liquid crystal;

[0032] depositing a liquid crystal layer anode on the glass or the second liquid crystal external cavity layer;

[0033] Spin coating an alignment film on the anode of the liquid crystal layer;

[0034] A glass or a second liquid crystal outer cavity layer is placed above the spacer spacer layer, and then liquid crystal is injected into the groove to form a liquid crystal layer.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] The present invention laminates a liquid crystal layer on the basis of a VCSEL array laser, changes the refractive index value of the liquid crystal layer by adjusting the voltage, and further adjusts the phase difference and beam direction between the light-emitting units, thereby solving the problem of poor beam quality of traditional VCSEL array lasers and achieving high beam quality in-phase mode coherent array laser output. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic structural diagram of a top-emitting two-phase array VCSEL laser beam control device disclosed in Example 1 of the present invention;

[0038] Figure 2 It is a schematic structural diagram of a bottom-emitting two-phase array VCSEL laser beam control device disclosed in Example 2 of the present invention;

[0039] Figure 3 A flow chart of the preparation of the two-phase array VCSEL laser beam control device disclosed in Example 1 or Example 2 of the present invention;

[0040] Figure 4 A schematic diagram of a two-phase array VCSEL laser beam control device implementing mutual injection feedback in Example 1 of the present invention;

[0041] Figure 5 This is a schematic diagram of a two-phase array VCSEL laser beam control device according to Embodiment 1 of the present invention that realizes adjustable beam direction.

[0042] In the figure:

[0043] 1. Substrate layer; 2. N-type DBR layer; 3. N-type waveguide layer; 4. Semiconductor multi-quantum well layer; 5. P-type waveguide layer; 6. Oxidation restriction layer; 7. P-type DBR layer; 8. Passivation layer; 9. P electrode; 10. N electrode; 11. Pad spacer layer; 12. Liquid crystal layer; 13. Liquid crystal layer cathode; 14. Orientation film; 15. Liquid crystal layer anode; 16. Glass. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0046] The present invention provides a laser beam control device comprising a VCSEL inner cavity layer and a liquid crystal outer cavity layer, wherein the liquid crystal layer, as a material with anisotropic optical properties, can change the deflection direction of the liquid crystal under the action of an external electric field and thus affect the refractive index value; precisely because of its electro-birefringence characteristics, mutual injection locking between VCSEL light output units can be achieved, the selection of in-phase mode and out-of-phase mode can be achieved, the light output direction of the VCSEL can be controlled, and the in-phase mode coherent output of the VCSEL array laser can be formed.

[0047] The light beam control device of the present invention comprises a VCSEL inner cavity layer, a first liquid crystal outer cavity layer and a second liquid crystal outer cavity layer, wherein the VCSEL inner cavity layer is a VCSEL epitaxial structure grown on a wafer, and light-emitting units arranged in a certain periodicity are prepared on the VCSEL epitaxial structure; the first liquid crystal outer cavity layer is closely attached to the surface of the light-emitting area of ​​the VCSEL inner cavity layer as a reflective layer, and the second liquid crystal outer cavity layer is closely attached to the upper part of the first liquid crystal outer cavity layer; wherein the first liquid crystal outer cavity layer can perform light feedback on the light-emitting array by point-by-point addressing and changing the refractive index, so as to realize mutual injection locking of the light-emitting units; the first liquid crystal outer cavity layer, as a phase control layer, can correspondingly adjust the phase at the position of each VCSEL light-emitting unit, control the overall phase of the VCSEL laser array, realize the selection of the same-phase mode, and obtain VCSEL coherent laser; the second liquid crystal outer cavity layer controls the phase of the light field by introducing a refractive index gradient difference between the second liquid crystal outer cavity layer and the first liquid crystal outer cavity layer at the corresponding light-emitting unit along the light beam path, so as to change the exit direction of the laser beam, and realize lens-free focusing.

[0048] Embodiment 1:

[0049] like Figure 1 As shown, the present invention provides a top-emitting two-phase array VCSEL laser beam control device, comprising a VCSEL inner cavity layer and a first liquid crystal outer cavity layer;

[0050] The VCSEL inner cavity layer is a VCSEL epitaxial structure grown on a wafer, and light-emitting units arranged in a certain periodicity are prepared on the VCSEL epitaxial structure; it includes an N-type DBR layer 2, an N-type waveguide layer 3, a semiconductor multi-quantum well layer 4, a P-type waveguide layer 5, an oxidation restriction layer 6 and a P-type DBR layer 7 grown in sequence on a GaAs substrate layer 1, a first liquid crystal outer cavity layer is formed on the surface of the central light-emitting region of the P-type DBR layer 7, a P electrode 9 is formed by sputtering a part of the surface, and a SiO2 passivation layer 8 is deposited on the remaining part of the surface, and an N electrode 10 is formed on the bottom surface of the substrate layer 1;

[0051] The first liquid crystal external cavity layer includes a liquid crystal layer cathode 13, a liquid crystal layer 12, a liquid crystal layer anode 15 and a glass 16 (optional) which are arranged in sequence from the surface of the P-type DBR layer 7. An orientation film 14 is provided between the liquid crystal layer cathode 13 and the liquid crystal layer 12 and between the liquid crystal layer anode 15 and the liquid crystal layer 12. A pad spacer layer 11 is provided between the liquid crystal layer anode 15 and the P electrode 9.

[0052] Furthermore, the reflectivity of the P-type DBR layer is 50%-99%, which cannot reach the laser light emission threshold; the reflectivity of the surface liquid crystal layer as the external cavity feedback layer is 65%-99%, which can reach the laser light emission threshold after feedback.

[0053] like Figure 4As shown, the first liquid crystal external cavity layer of the present invention is closely attached to the surface of the VCSEL internal cavity layer as a reflective layer, which can address point by point to change the refractive index to perform optical feedback on the light-emitting array, and realize mutual injection locking of the light-emitting units, wherein the refractive index of the first liquid crystal external cavity layer is different from the refractive index of the adjacent external material; further, the first liquid crystal external cavity layer is used as a phase control layer, which can adjust the phase at the position of each VCSEL light-emitting unit accordingly, control the overall phase of the VCSEL laser array, realize the selection of the same-phase mode, and obtain VCSEL coherent laser. Among them, the distance d satisfies the design of the coherence of adjacent light-emitting units, that is, as Figure 4 shown.

[0054] Further, if Figure 5 As shown, in the present invention, a second liquid crystal external cavity layer (which can replace glass 16) as a beam modulation layer can be closely disposed above the first liquid crystal external cavity layer, and the refractive index of the second liquid crystal external cavity layer can be different from the refractive index of the first liquid crystal external cavity layer, that is, the refractive index of the first liquid crystal external cavity layer is n1, and the refractive index of the second liquid crystal external cavity layer is n3; by introducing a refractive index gradient difference between the first liquid crystal external cavity layer and the corresponding light-emitting unit along the beam path, the light field phase can be controlled to change the exit direction of the laser beam, thereby achieving lens-free focusing.

[0055] like Figure 3 As shown, the present invention provides a method for preparing a top-emitting two-phase array VCSEL laser beam control device, comprising:

[0056] S1. Growth of epitaxial structure

[0057] Epitaxially growing an N-type DBR layer, an N-type waveguide layer, a semiconductor multi-quantum well layer, a P-type waveguide layer, an oxide layer, and a P-type DBR layer on the surface of a GaAs substrate in sequence;

[0058] S2. Making the countertop

[0059] First, use wet etching or dry etching to make a mesa structure on the epitaxial wafer to be processed. If the etching method is used, the Cl2 / BCl3 gas flow ratio is 1:3, the etching power is 500W, and the chip is etched to expose the oxide layer. Secondly, wet etch away the excess SiO2 on the chip and clean the chip. Finally, after cleaning, blow dry the epitaxial wafer to be processed with high-purity nitrogen gas. After ensuring that it is clean, heat and dry the wafer for standby use;

[0060] S3. Making oxidation holes

[0061] Utilize wet selective oxidation technology to oxidize the oxide layer in the table of the epitaxial wafer to be processed from the outside to form an oxidation aperture. Wet selective oxidation process: The oxidation furnace is heated to 430°C, the water temperature is set to 100°C, a trace amount of N2 is passed at a flow rate of 1L / min, and it is stabilized for 20 minutes to remove excess air in the oxidation furnace. After 20 minutes, N2 is started to flow at a flow rate of 9L / min and stabilized for 30 minutes. After stabilizing for 30 minutes, the epitaxial wafer is placed in the oxidation furnace for oxidation. The oxidation time depends on the oxidation aperture that needs to be oxidized. After the oxidation is completed, wait for the furnace temperature to drop to 80°C, then take out the epitaxial wafer and set it aside;

[0062] S4. Deposition of passivation layer

[0063] A SiO2 passivation layer is deposited using plasma enhanced chemical vapor deposition (PECVD), and a laser light exit window is further photolithographically etched;

[0064] S5. Fabrication of metal P electrode after photolithography

[0065] The epitaxial wafer to be processed is coated with L300 negative photoresist, and the P electrode pattern is made through photolithography and development, and then the P electrode metal material is grown through metal processes such as magnetron sputtering technology;

[0066] The epitaxial wafer on which the P electrode metal has been grown is immersed in an acetone solution for 4 to 6 hours, and then a metal stripping process is performed to strip off the non-P electrode metal to make a metal P electrode;

[0067] S6. Making metal N electrode

[0068] Grind and polish the GaAs substrate to reduce it to a certain thickness;

[0069] Growing N-electrode metal material on the thinned substrate by magnetron sputtering technology and other metal processes;

[0070] S7, preparing a surface liquid crystal layer (a first liquid crystal outer cavity layer, or a first liquid crystal outer cavity layer and a second liquid crystal outer cavity layer)

[0071] A conductive layer is deposited on the light-emitting table using PECVD as the cathode of the liquid crystal layer, and then the alignment film material is spin-coated on the conductive layer. After photolithography, a liner material is spin-coated on the P electrode of the lower table as a deep groove for injecting liquid crystal; and a conductive layer is deposited on the glass as the anode of the liquid crystal layer. The glass is placed above the liner material, and finally the liquid crystal is injected into the deep groove and sealed;

[0072] S8, Decomposition and Packaging

[0073] The manufactured chip is cleaved with a cleavage saw, and is welded to the electrodes of the external power supply system by means of hot pressing and other methods, and the chip is packaged.

[0074] Embodiment 2:

[0075] like Figure 2 As shown, the present invention provides a bottom-emitting two-phase array VCSEL laser beam control device, including a VCSEL epitaxial structure and a first liquid crystal external cavity layer;

[0076] The VCSEL epitaxial structure includes an N-type DBR layer 2, an N-type waveguide layer 3, a semiconductor multi-quantum well layer 4, a P-type waveguide layer 5, an oxidation restriction layer 6 and a P-type DBR layer 7 grown in sequence on a GaAs substrate layer 1. A P electrode 9 is formed by sputtering in the central region of the P-type DBR layer 7, and a SiO2 passivation layer 8 is deposited on the surface of the remaining portion. A first liquid crystal external cavity layer is formed on the surface of the central light-emitting region of the bottom surface of the substrate layer 1, and an N electrode 10 is formed by sputtering on the remaining surface.

[0077] The first liquid crystal external cavity layer includes a liquid crystal layer cathode 13, a liquid crystal layer 12, a liquid crystal layer anode 15 and a glass 16 (optional) which are arranged in sequence from the surface of the substrate layer 1, an orientation film 14 is arranged between the liquid crystal layer cathode 13 and the liquid crystal layer 12 and between the liquid crystal layer anode 15 and the liquid crystal layer 12, and a spacer spacer 11 is arranged between the liquid crystal layer anode 15 and the N electrode 10.

[0078] The first liquid crystal external cavity layer of the present invention is closely attached to the surface of the VCSEL internal cavity layer as a reflective layer, which can address point by point to change the refractive index to perform optical feedback on the light-emitting array, and realize mutual injection locking of the light-emitting units, wherein the refractive index of the first liquid crystal external cavity layer is different from the refractive index of the adjacent external material; further, the first liquid crystal external cavity layer is used as a phase control layer, which can adjust the phase at the position of each VCSEL light-emitting unit accordingly, control the overall phase of the VCSEL laser array, realize the selection of the same-phase mode, and obtain VCSEL coherent laser. Wherein, the distance d satisfies the design of the coherence of adjacent light-emitting units, that is, as Figure 4 shown.

[0079] Furthermore, the present invention may provide a second liquid crystal external cavity layer as a beam modulation layer in close contact above the first liquid crystal external cavity layer, and the refractive index of the second liquid crystal external cavity layer may be different from that of the first liquid crystal external cavity layer, that is, the refractive index of the first liquid crystal external cavity layer is n1, and the refractive index of the second liquid crystal external cavity layer is n3; by introducing a refractive index gradient difference between the first liquid crystal external cavity layer and the corresponding light-emitting unit along the beam path, the light field phase can be controlled to change the emission direction of the laser beam, thereby achieving lens-free focusing.

[0080] like Figure 3 As shown, the present invention provides a method for preparing a bottom-emitting two-phase array VCSEL laser beam control device, comprising:

[0081] S1. Growth of epitaxial structure

[0082] Epitaxially growing an N-type DBR layer, an N-type waveguide layer, a semiconductor multi-quantum well layer, a P-type waveguide layer, an oxide layer, and a P-type DBR layer on the surface of a GaAs substrate in sequence;

[0083] S2. Making the countertop

[0084] First, use wet etching or dry etching to make a mesa structure on the epitaxial wafer to be processed. If the etching method is used, the Cl2 / BCl3 gas flow ratio is 1:3, the etching power is 500W, and the chip is etched to expose the oxide layer. Secondly, wet etch away the excess SiO2 on the chip and clean the chip. Finally, after cleaning, blow dry the epitaxial wafer to be processed with high-purity nitrogen gas. After ensuring that it is clean, heat and dry the wafer for standby use;

[0085] S3. Making oxidation holes

[0086] Utilize wet selective oxidation technology to oxidize the oxide layer in the table of the epitaxial wafer to be processed from the outside to form an oxidation aperture. Wet selective oxidation process: The oxidation furnace is heated to 430°C, the water temperature is set to 100°C, a trace amount of N2 is passed at a flow rate of 1L / min, and it is stabilized for 20 minutes to remove excess air in the oxidation furnace. After 20 minutes, N2 is started to flow at a flow rate of 9L / min and stabilized for 30 minutes. After stabilizing for 30 minutes, the epitaxial wafer is placed in the oxidation furnace for oxidation. The oxidation time depends on the oxidation aperture that needs to be oxidized. After the oxidation is completed, wait for the furnace temperature to drop to 80°C, then take out the epitaxial wafer and set it aside;

[0087] S4. Deposition of passivation layer

[0088] The SiO2 passivation layer is deposited by plasma enhanced chemical vapor deposition (PECVD), and the laser light output window is further photolithographically and etched.

[0089] S5. Making metal P electrode

[0090] The epitaxial wafer to be processed is coated with L300 negative photoresist, and the P electrode pattern is made through photolithography and development, and then the P electrode metal material is grown through metal processes such as magnetron sputtering technology;

[0091] Step 6: Stripping non-P electrode metal

[0092] The epitaxial wafer on which the P electrode metal has been grown is immersed in an acetone solution for 4 to 6 hours, and then a metal stripping process is performed to strip off the non-P electrode metal to make a metal P electrode;

[0093] S6. Making metal N electrode

[0094] Grind and polish the GaAs substrate to reduce it to a certain thickness;

[0095] Make N electrode pattern on the back of the epitaxial wafer to be processed, and grow N electrode metal material by magnetron sputtering technology and other metal processes;

[0096] S7, preparing a surface liquid crystal layer (a first liquid crystal outer cavity layer, or a first liquid crystal outer cavity layer and a second liquid crystal outer cavity layer)

[0097] A conductive layer is deposited on the light-emitting surface using PECVD as the cathode of the liquid crystal layer, and then the alignment film material is spin-coated on the conductive layer. After photolithography, the liner material is spin-coated on the N electrode as the deep groove for injecting liquid crystal. A conductive layer is deposited on the glass as the anode of the liquid crystal layer. The glass is placed above the liner material, and finally the liquid crystal is injected into the deep groove and sealed.

[0098] S8, Decomposition and Packaging

[0099] The manufactured chip is cleaved with a cleavage saw, and is welded to the electrodes of the external power supply system by means of hot pressing and other methods, and the chip is packaged.

[0100] The advantages of the present invention are:

[0101] The present invention combines a double-layer liquid crystal external cavity layer with a traditional VCSEL array laser to achieve adjustment of the beam phase, direction and reflection, and ultimately forms a coherent array laser with adjustable beam direction and wafer-level in-phase mode selection function without lens focusing, thereby solving the problem of poor beam quality of the traditional VCSEL laser array.

[0102] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A two-phase array VCSEL laser beam control device, characterized in that: include: A VCSEL inner cavity layer, a first liquid crystal outer cavity layer, and a second liquid crystal outer cavity layer; The VCSEL inner cavity layer is a VCSEL epitaxial structure grown on a wafer, and light-emitting units arranged in a certain periodicity are prepared on the VCSEL epitaxial structure; The first liquid crystal outer cavity layer is closely attached to the surface of the light emitting area of ​​the VCSEL inner cavity layer as a reflective layer; The second liquid crystal external cavity layer is closely attached to the top of the first liquid crystal external cavity layer. The second liquid crystal external cavity layer introduces a refractive index gradient difference along the beam path between the second liquid crystal external cavity layer and the first liquid crystal external cavity layer at the corresponding light-emitting unit to control the light field phase and change the emission direction of the laser beam to achieve lens-free focusing.

2. The two-phase array VCSEL laser beam control device according to claim 1, characterized in that: The first liquid crystal external cavity layer can be addressed point by point to change the refractive index to perform optical feedback on the light-emitting array, thereby realizing mutual injection locking of the light-emitting units.

3. The two-phase array VCSEL laser beam control device according to claim 2, characterized in that: The first liquid crystal external cavity layer serves as a phase control layer, which can correspondingly adjust the phase at the position of each VCSEL light-emitting unit, control the overall phase of the VCSEL laser array, realize the selection of the same-phase mode, and obtain VCSEL coherent laser.

4. The two-phase array VCSEL laser beam control device according to claim 1, characterized in that: A P electrode and an N electrode are formed on the VCSEL epitaxial structure. The VCSEL epitaxial structure is an array-type top-emitting or bottom-emitting structure, including an N-type DBR layer, an N-type waveguide layer, a semiconductor multi-quantum well layer, a P-type waveguide layer, an oxidation restriction layer and a P-type DBR layer grown in sequence on a substrate layer.

5. The two-phase array VCSEL laser beam control device according to claim 4, characterized in that: When the VCSEL epitaxial structure is an array-type top emission structure, the first liquid crystal external cavity layer is formed on the surface of the central light-emitting region of the P-type DBR layer, the P electrode is formed by sputtering on a portion of the surface, a passivation layer is deposited on the remaining portion of the surface, and the N electrode is formed on the bottom surface of the substrate layer; When the VCSEL epitaxial structure is an array-type bottom emission structure, the P-electrode is formed by sputtering in the central area of ​​the P-type DBR layer, and a passivation layer is deposited on the remaining surface; the first liquid crystal external cavity layer is formed on the surface of the central light-emitting area of ​​the bottom surface of the substrate layer, and the N-electrode is formed on the remaining surface by sputtering.

6. The two-phase array VCSEL laser beam control device according to claim 5, characterized in that: When the VCSEL epitaxial structure is an array-type top emission structure, the first liquid crystal external cavity layer includes a liquid crystal layer cathode, a liquid crystal layer, a liquid crystal layer anode and glass arranged in sequence from the surface of the P-type DBR layer, an alignment film is arranged between the liquid crystal layer cathode and the liquid crystal layer and between the liquid crystal layer anode and the liquid crystal layer, and a spacer layer is arranged between the liquid crystal layer anode and the P electrode; When the VCSEL epitaxial structure is an array-type bottom emission structure, the first liquid crystal external cavity layer includes a liquid crystal layer cathode, a liquid crystal layer, a liquid crystal layer anode and glass arranged in sequence from the surface of the substrate layer, an orientation film is provided between the liquid crystal layer cathode and the liquid crystal layer and between the liquid crystal layer anode and the liquid crystal layer, and a pad spacer layer is provided between the liquid crystal layer anode and the N electrode.

7. A method for preparing a two-phase array VCSEL laser beam control device according to any one of claims 1 to 6, characterized in that: include: Growing a VCSEL epitaxial structure, wherein the VCSEL epitaxial structure comprises an N-type DBR layer, an N-type waveguide layer, a semiconductor multi-quantum well layer, a P-type waveguide layer, an oxidation confinement layer and a P-type DBR layer sequentially grown on a substrate layer; A mesa is formed on the VCSEL epitaxial structure to expose the oxidation restriction layer, and an oxidation hole is formed on the oxidation restriction layer; Depositing a passivation layer on the mesa structure and etching out the laser light emitting area to make a P electrode and an N electrode; A first liquid crystal external cavity layer is formed on the top or bottom laser light emitting area; Preparing a second liquid crystal external cavity layer on the first liquid crystal external cavity layer; Decomposition package.

8. The preparation method according to claim 7, characterized in that: The method of manufacturing the first liquid crystal external cavity layer comprises: Depositing a liquid crystal layer cathode on the surface of the light emitting area; Spin coating an alignment film on the cathode of the liquid crystal layer; After photolithography, a spacer layer is spin-coated on the P electrode or the N electrode to form a groove for injecting liquid crystal; depositing a liquid crystal layer anode on the glass or the second liquid crystal external cavity layer; Spin coating an alignment film on the anode of the liquid crystal layer; A glass or a second liquid crystal outer cavity layer is placed above the spacer spacer layer, and then liquid crystal is injected into the groove to form a liquid crystal layer.

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