A vertical cavity surface laser with multi-angle laser output and a preparation method thereof

Abstract

The application relates to a vertical cavity surface laser with multi-angle laser output and a preparation method thereof. The application comprises a substrate, the upper surface of the substrate is provided with a groove; an N-type DBR mirror layer is arranged on the surface of the groove; an active layer is arranged on the surface of the N-type DBR mirror layer; an oxidation layer is arranged on the surface of the active layer; a P-type DBR mirror layer is arranged on the surface of the oxidation layer; a P-surface electrode layer is arranged on the surface of the P-type DBR mirror layer, the surface of the P-surface electrode layer is provided with a central light-emitting hole; an N-surface electrode layer is arranged on the lower surface of the substrate; the surface of the groove comprises the following forms: a plurality of annularly arranged straight surfaces, or a straight surface located at the bottom and a plurality of annularly arranged straight surfaces, or an arc surface, or a combination of an arc surface and a straight surface; the oxidation layer is provided with a plurality of oxidation holes, and each oxidation hole is arranged correspondingly to each straight surface or arc surface on the groove. The application can realize multi-angle laser synchronous output.

Description

A vertical cavity surface laser with multi-angle laser output and its fabrication method Technical Field

[0001] This invention relates to the field of semiconductor laser technology, and in particular to a vertical cavity surface laser with multi-angle laser output and its fabrication method. Background Technology

[0002] With the rapid development of the information society, fields such as 3D printing, LiDAR, medical aesthetics, and even optical communication are placing new demands on the laser output angle of Vertical Cavity Surface Emitting Lasers (VCSELs). Because traditional VCSEL structures are grown vertically on horizontal substrates, their light output direction is perpendicular to the substrate, resulting in a relatively singular output direction and limiting the laser power level. How to achieve multi-angle laser output, increase laser coverage, and improve laser integration has become a research hotspot both domestically and internationally.

[0003] To address the aforementioned issues with VCSEL lasers, a laser beam splitter is typically used externally to divide the laser beam into multiple output angles. However, laser beam splitters have high requirements for the power and wavelength of the laser beam, and the beam distribution is unstable and susceptible to external interference. Another approach is to use laser mirrors to reflect the laser beam at different angles, thus achieving multi-angle output. However, the mirrors require high quality and precision, and their surfaces are easily contaminated and damaged, necessitating periodic replacement. In summary, existing methods all suffer from drawbacks such as low integration, difficult adjustment, and high cost. Summary of the Invention

[0004] Therefore, the present invention provides a vertical cavity surface laser with multi-angle laser output and its fabrication method, which has high integration, wide beam coverage and can realize synchronous multi-angle laser output, and achieve the effect of increasing power.

[0005] To solve the above-mentioned technical problems, the present invention provides a vertical cavity surface laser with multi-angle laser output, comprising:

[0006] A substrate, wherein a groove is provided on the upper surface of the substrate;

[0007] An N-type DBR reflector layer is disposed on the surface of the groove;

[0008] An active layer is disposed on the surface of the N-type DBR mirror layer;

[0009] An oxide layer is disposed on the surface of the active layer;

[0010] A P-type DBR reflector layer is disposed on the surface of the oxide layer;

[0011] A P-side electrode layer is disposed on the surface of a P-type DBR reflector layer, and a central light-emitting hole is provided on the surface of the P-side electrode layer.

[0012] An N-plane electrode layer is disposed on the lower surface of the substrate;

[0013] The surface of the groove includes the following forms: composed of multiple circumferentially arranged straight surfaces, or composed of a straight surface located at the bottom and multiple circumferentially arranged straight surfaces, or an arc surface, or a combination of an arc surface and a straight surface;

[0014] The oxide layer is provided with a plurality of oxide holes, each of which is provided corresponding to a straight or curved surface on the groove to achieve multi-angle laser output.

[0015] In one embodiment of the present invention, the active layer is made of one of AlGaAs, AlGaInAs, and GaAs.

[0016] In one embodiment of the present invention, the oxide layer is an AlAs oxide layer.

[0017] In one embodiment of the present invention, the size of the central light-emitting aperture is larger than the size of each of the oxide apertures.

[0018] In one embodiment of the invention, the shape of the groove includes trapezoidal and rhomboid.

[0019] In one embodiment of the present invention, the substrate is a GaAs substrate.

[0020] This invention also provides a method for fabricating a vertical cavity surface laser with multi-angle laser output, comprising:

[0021] Provide GaAs substrates;

[0022] A groove is formed on the surface of the GaAs substrate, wherein the surface of the groove includes the following forms: composed of a plurality of circumferentially arranged straight surfaces, or composed of a straight surface located at the bottom and a plurality of circumferentially arranged straight surfaces, or an arc surface, or a combination of an arc surface and a straight surface;

[0023] An N-type DBR reflector layer is formed by alternating growth of N-doped AlGaAs layers with different compositions on the groove surface of the GaAs substrate using metal-organic chemical vapor deposition.

[0024] An active layer is grown on the surface of the N-type DBR reflector layer;

[0025] An AlAs oxide layer is grown on the surface of the active layer;

[0026] P-doped AlGaAs are alternately grown on the surface of the AlAs oxide layer by metal-organic chemical vapor deposition to form a P-type DBR mirror layer and obtain a VCSEL structure.

[0027] A surface is etched onto the outer side of the VCSEL structure using photolithography.

[0028] Multiple oxide holes are created on the surface of the oxide layer by side oxidation, wherein each oxide hole is provided corresponding to each straight or curved surface on the groove to achieve multi-angle laser output;

[0029] A central light-emitting hole was fabricated on the surface of the VCSEL structure using photolithography.

[0030] A P-side electrode layer is fabricated around the central light-emitting aperture by vapor deposition of metal.

[0031] After thinning and polishing the GaAs substrate, an N-plane electrode layer is deposited on its bottom surface.

[0032] In one embodiment of the present invention, the step of forming a groove on the surface of the GaAs substrate includes:

[0033] The GaAs substrate is surface cleaned;

[0034] Photoresist is poured onto the surface of the GaAs substrate and then uniformly coated onto the surface of the GaAs substrate using a spin coater.

[0035] The process involves creating a photomask pattern, placing the pattern on a mask, bringing the mask into contact with the photoresist, and then placing it in the exposure area of ​​the lithography machine for ultraviolet exposure using an exposure light source.

[0036] After exposure, use a developer to remove the unexposed photoresist, leaving the photoresist in the exposed areas;

[0037] The photomask pattern is transferred onto the substrate, the photoresist sample is placed in a dry etching apparatus, and the exposed part of the photoresist sample is peeled off.

[0038] Repeat the above steps to obtain a groove shape with a predetermined depth and precision.

[0039] In one embodiment of the present invention, the groove is trapezoidal in shape.

[0040] In one embodiment of the present invention, the groove is rhomboid in shape.

[0041] The technical solution of the present invention has the following advantages compared with the prior art:

[0042] This invention discloses a vertical cavity surface laser (VCSEL) with multi-angle laser output and its fabrication method, which can realize multi-angle laser output from a VCSEL laser. Since the output direction of a VCSEL laser is perpendicular to the substrate direction, this invention can achieve synchronous laser output in different directions by changing the shape of the substrate groove, resulting in high integration, wide beam coverage, and increased power. Attached Figure Description

[0043] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0044] Figure 1 is a schematic diagram of a vertical cavity laser with a trapezoidal groove structure according to an embodiment of the present invention.

[0045] Figure 2 is a schematic diagram of a vertical cavity laser with a rhomboid groove structure in one embodiment of the present invention.

[0046] Figure 3 is a schematic diagram of the vertical cavity surface laser prepared according to Embodiment 2 of the present invention.

[0047] Figure 4 is a schematic diagram of the process of making the groove in Embodiment 2 of the present invention.

[0048] Explanation of reference numerals in the instruction manual:

[0049] 1. Substrate;

[0050] 2. Groove;

[0051] 3. N-type DBR reflector layer;

[0052] 4. Active layer;

[0053] 5. Oxide layer;

[0054] 6. P-type DBR reflector layer;

[0055] 7. P-side electrode layer;

[0056] 8. Center light-emitting aperture;

[0057] 9. N-side electrode layer;

[0058] 10. Oxidation pores;

[0059] 101. GaAs substrate; 102. Groove; 103. N-type DBR mirror layer; 104. Active layer; 105. AlAs oxide layer; 106. P-type DBR mirror layer; 107. Mesa, oxide hole; 108. Center light-emitting hole; 109. P-side electrode layer; 110. N-side electrode layer. Detailed Implementation

[0060] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0061] In this invention, when directions (up, down, left, right, front, and back) are described, it is only for the convenience of describing the technical solution of this invention, and does not indicate or imply that the technical features referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0062] In this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," "exceeding," etc., are understood to exclude the stated number; "above," "below," "within," etc., are understood to include the stated number. In the description of this invention, the terms "first" and "second" are used only to distinguish technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0063] In this invention, unless otherwise explicitly defined, the terms "setting," "installing," and "connecting" should be interpreted broadly. For example, they can refer to a direct connection or an indirect connection through an intermediate medium; a fixed connection, a detachable connection, or an integrally formed connection; a mechanical connection, an electrical connection, or a connection capable of mutual communication; or the internal connection of two components or the interaction between two components. Those skilled in the art can reasonably determine the specific meaning of the above terms in this invention based on the specific content of the technical solution.

[0064] Example 1

[0065] Referring to Figures 1 and 2, a vertical cavity surface laser with multi-angle laser output according to the present invention includes:

[0066] Substrate 1, wherein a groove 2 is provided on the upper surface of substrate 1;

[0067] N-type DBR reflector layer 3 is disposed on the surface of the groove 2;

[0068] Active layer 4 is disposed on the surface of the N-type DBR reflector layer 3;

[0069] Oxide layer 5 is disposed on the surface of active layer 4;

[0070] P-type DBR reflector layer 6 is disposed on the surface of oxide layer 5;

[0071] P-side electrode layer 7 is disposed on the surface of P-type DBR reflector layer 6, and a central light-emitting hole 8 is provided on the surface of P-side electrode layer 7;

[0072] N-side electrode layer 9 is disposed on the lower surface of the substrate 1;

[0073] The surface of the groove 2 includes the following forms: it is composed of multiple circumferentially arranged straight surfaces, or it is composed of a straight surface located at the bottom and multiple circumferentially arranged straight surfaces, or it is an arc surface, or a combination of arc surface and straight surface;

[0074] The oxide layer 5 is provided with a plurality of oxide holes 10, each of which is provided corresponding to a straight or curved surface on the groove 2 to achieve multi-angle laser output.

[0075] With the above settings, since the light output direction of the VCSEL laser is perpendicular to the direction of the substrate 1, the present invention can achieve synchronous laser output in different directions by changing the shape of the groove 2 of the substrate 1, resulting in high integration, wide beam coverage, and increased power.

[0076] Specifically, the active layer 4 is made of one of AlGaAs, AlGaInAs, or GaAs.

[0077] Specifically, the oxide layer 5 is an AlAs oxide layer 5.

[0078] Specifically, the size of the central light-emitting aperture 8 is larger than the size of each of the oxide apertures 10.

[0079] In some embodiments, the internal space of the groove 2 is shaped as a frustum (i.e., composed of a straight surface at the bottom and multiple straight surfaces arranged in a ring) and a pyramid (i.e., composed of multiple straight surfaces arranged in a ring). The groove 2 in Figure 1 is shaped as an isosceles trapezoid (i.e., the internal space is an inverted quadrangular isosceles frustum), and the groove 2 in Figure 2 is shaped as a rhombus (i.e., the internal space is an inverted quadrangular pyramid). The substrate 1 with the rhombus-shaped groove 2 can realize multi-directional light emission of the laser. In other embodiments, the shape of the groove 2 can be a frustum, a cone (i.e., an arc surface, or a combination of an arc surface and a straight surface), etc.

[0080] Specifically, the substrate 1 is a GaAs substrate 1.

[0081] Example 2

[0082] Referring to Figure 3, this embodiment provides a method for fabricating a vertical cavity surface laser with multi-angle laser output, including:

[0083] S1. Provide a GaAs substrate 101;

[0084] S2. A groove 102 is formed on the surface of the GaAs substrate 101, wherein the surface of the groove 102 includes the following forms: composed of a plurality of circumferentially arranged straight surfaces, or composed of a straight surface located at the bottom and a plurality of circumferentially arranged straight surfaces, or an arc surface, or a combination of an arc surface and a straight surface.

[0085] S3. N-doped AlGaAs layers with different compositions are alternately grown on the surface of the groove 102 of the GaAs substrate 101 by metal-organic chemical vapor deposition to form an N-type DBR reflector layer 103.

[0086] S4. An active layer 104 is grown on the surface of the N-type DBR mirror layer 103;

[0087] S5. An AlAs oxide layer 105 is grown on the surface of the active layer 104;

[0088] S6. P-doped AlGaAs are alternately grown on the surface of the AlAs oxide layer 105 by metal-organic chemical vapor deposition to form a P-type DBR mirror layer 106 and obtain a VCSEL structure.

[0089] S7. The surface 107 is etched onto the outer side of the VCSEL structure by photolithography;

[0090] S8. Multiple oxide holes 111 are formed on the surface of the oxide layer by side oxidation, wherein each oxide hole 111 is provided corresponding to each straight or arc surface on the groove 102 to achieve multi-angle laser output;

[0091] S9. A central light-emitting hole 108 is fabricated on the surface of the VCSEL structure by photolithography;

[0092] S10. A P-surface electrode layer 109 is formed around the central light-emitting hole 108 by vapor deposition of metal.

[0093] S11. After thinning and polishing the GaAs substrate 101, an N-side electrode layer 110 is deposited on its bottom surface.

[0094] Referring to FIG4, specifically, the step of forming a groove 102 on the surface of the GaAs substrate 101 includes:

[0095] S21. Perform surface cleaning on the GaAs substrate 101;

[0096] S22. Pour photoresist onto the surface of the GaAs substrate 101 and use a spin coater to uniformly coat the photoresist onto the surface of the GaAs substrate 101.

[0097] S23. Fabricate the photomask pattern, place the photomask pattern on the mask, put the mask in contact with the photoresist, and place it in the exposure area of ​​the photolithography machine for ultraviolet exposure through the exposure light source;

[0098] S24. After exposure, use a developer to remove the unexposed photoresist, leaving the photoresist in the exposed area.

[0099] S25. Transfer the photomask pattern onto the substrate, place the photoresist sample into the dry etching equipment, and peel off the exposed part of the photoresist sample.

[0100] S26. Repeat the above steps to obtain the shape of the groove 102 with a predetermined depth and precision.

[0101] Specifically, the groove 102 is trapezoidal or rhomboid in shape.

[0102] By changing the shape of the substrate groove 102, synchronous laser output in different directions can be achieved, resulting in high integration, wide beam coverage, and increased power.

[0103] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A vertical-cavity surface mount laser with multi-angle laser output, characterized in that, include: A substrate, wherein a groove is provided on the upper surface of the substrate; an N-type DBR reflector layer is disposed on the surface of the groove. An active layer is disposed on the surface of the N-type DBR mirror layer; An oxide layer is disposed on the surface of the active layer; A P-type DBR reflector layer is disposed on the surface of the oxide layer; a P-face electrode layer is disposed on the surface of the P-type DBR reflector layer, and a central light-emitting aperture is disposed on the surface of the P-face electrode layer; an N-face electrode layer is disposed on the lower surface of the substrate; wherein, the surface of the groove includes the following forms: composed of multiple circumferentially arranged straight surfaces, or composed of a straight surface located at the bottom and multiple circumferentially arranged straight surfaces, or an arc surface, or a combination of arc surface and straight surface; wherein, the oxide layer is provided with multiple oxide holes, each oxide hole corresponding to each straight surface or arc surface on the groove to achieve multi-angle laser output; the size of the central light-emitting aperture is larger than the size of each oxide hole.

2. A vertical-cavity surface mount laser with multi-angle laser output according to claim 1, characterized in that, The active layer is made of one of AlGaAs, AlGaInAs, or GaAs.

3. A vertical cavity surface laser with multi-angle laser output according to claim 1, characterized in that, The oxide layer is an AlAs oxide layer.

4. A vertical-cavity surface mount laser with multi-angle laser output according to claim 1, characterized in that, The groove can be trapezoidal or rhomboid in shape.

5. A vertical-cavity surface mount laser with multi-angle laser output according to claim 1, characterized in that, The substrate is a GaAs substrate.

6. A method for fabricating a vertical-cavity surface-mount laser with multi-angle laser output, characterized in that, include: A GaAs substrate is provided; a groove is formed on the surface of the GaAs substrate, wherein the surface of the groove has the following forms: composed of a plurality of circumferentially arranged straight surfaces, or composed of a straight surface located at the bottom and a plurality of circumferentially arranged straight surfaces, or an arc surface, or a combination of arc surfaces and straight surfaces; N-doped AlGaAs layers of different compositions are alternately grown on the surface of the groove of the GaAs substrate by metal-organic chemical vapor deposition to form an N-type DBR mirror layer; an active layer is grown on the surface of the N-type DBR mirror layer; an AlAs oxide layer is grown on the surface of the active layer; and an active layer is grown on the surface of the active layer by metal-organic chemical vapor deposition. P-doped AlGaAs are alternately grown on the surface of the AlAs oxide layer to form a P-type DBR reflector layer and obtain a VCSEL structure. A surface is etched on the outer side of the VCSEL structure by photolithography. Multiple oxide holes are formed on the surface of the oxide layer by side oxidation, wherein each oxide hole corresponds to a straight or curved surface on the groove to achieve multi-angle laser output. A central light-emitting hole is formed on the surface of the VCSEL structure by photolithography. A P-face electrode layer is formed around the central light-emitting hole by metal evaporation. After thinning and polishing the GaAs substrate, an N-face electrode layer is deposited on its bottom surface.

7. The method for fabricating a vertical-cavity surface-mount laser with multi-angle laser output as described in claim 6, characterized in that, The process of creating a groove on the GaAs substrate surface includes: cleaning the GaAs substrate surface; pouring photoresist onto the GaAs substrate surface and uniformly coating the photoresist onto the GaAs substrate surface using a spin coater; creating a photomask pattern by placing the photomask pattern on a mask, contacting the mask with the photoresist, and placing it in the exposure area of ​​a photolithography machine for ultraviolet exposure using an exposure light source; after exposure, removing the unexposed photoresist using a developer, retaining the photoresist in the exposed area; transferring the photomask pattern onto the substrate, placing the photoresist sample in a dry etching apparatus, and peeling off the exposed portion of the photoresist sample; repeating the above steps to obtain a groove shape of predetermined depth and precision.

8. The method for fabricating a vertical-cavity surface-mount laser with multi-angle laser output as described in claim 6, characterized in that, The groove is trapezoidal in shape.

9. The method for fabricating a vertical-cavity surface-mount laser with multi-angle laser output as described in claim 6, characterized in that, The groove is rhomboid in shape.

Images