A vertical-cavity surface-emitting laser and its fabrication method

Abstract

This invention discloses a vertical-cavity surface-emitting laser (VCSEL) and its fabrication method. The VCSEL includes: a substrate; a first reflective layer; an active region; a second reflective layer; an oxide layer including oxide apertures; a support layer including vias, the vertical projection of which onto the substrate overlaps with the vertical projection of the oxide apertures onto the substrate; and a microelectromechanical system (MEMS) structure located on the side of the support layer away from the second reflective layer. The MEMS structure includes a grating structure and a strain beam structure. The grating structure is suspended from the second reflective layer away from the active region via the strain beam structure. The vertical projection of the grating structure onto the substrate overlaps with the vertical projection of the oxide apertures onto the substrate. When the MEMS structure is energized, the strain beam structure drives the grating structure to rotate in a plane parallel to the first surface. This invention enables the moduliability of the emitted polarization state of the VCSEL.

Description

Technical Field

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

[0002] Vertical-cavity surface-emitting lasers (VCSELs), as a type of semiconductor laser, offer advantages over traditional edge-emitting lasers and LEDs, including a circular beam, small divergence angle, low threshold current, and the ability to directly grow components and form two-dimensional close-packed arrays of testing and emission apertures on the wafer. Based on these characteristics, VCSELs have been widely used in high-speed optical communications, consumer electronics, automotive radar, and medical aesthetics in recent years.

[0003] Since the light-emitting aperture of a VCSEL is usually circular, the various polarization states of the corresponding emitted transverse mode are energy degenerate. Therefore, the emitted light of a conventional VCSEL structure does not have specific polarization characteristics.

[0004] To achieve output with a single polarization state, researchers developed a high-refractive-index contrast grating (HCG) placed on the top layer of a VCSEL. When this grating is placed on the top layer of a VCSEL, it can achieve the output of light with a specific polarization, but it cannot achieve the tunable polarization state. Summary of the Invention

[0005] This invention provides a vertical cavity surface-emitting laser and its fabrication method to achieve moduliability of the emitted polarization state of the vertical cavity surface-emitting laser.

[0006] According to one aspect of the present invention, a vertical-cavity surface-emitting laser is provided, comprising:

[0007] Substrate;

[0008] The first reflective layer is located on one side of the substrate;

[0009] The active region is located on the side of the first reflective layer furthest from the substrate;

[0010] The second reflective layer is located on the side of the active region away from the first reflective layer;

[0011] An oxide layer is located within the first or second reflective layer, and is adjacent to the active region. The oxide layer includes oxide pores.

[0012] A support layer is located on the first surface of the second reflective layer. The support layer includes vias, wherein the first surface is the surface of the second reflective layer away from the active region, and the vertical projection of the vias on the substrate covers the vertical projection of the oxide aperture on the substrate.

[0013] The micro-motor structure is located on the side of the support layer away from the second reflective layer. The micro-motor structure includes a grating structure and a strain beam structure. The grating structure is suspended on the side of the second reflective layer away from the active region through the strain beam structure. The vertical projection of the grating structure on the substrate overlaps with the vertical projection of the oxide aperture on the substrate.

[0014] When the micro-motor structure is energized, the strain beam structure drives the grating structure to rotate on a plane parallel to the first surface.

[0015] Optionally, when the micro motor structure receives the first voltage, the grating structure rotates by a first set angle;

[0016] When the micro motor structure receives the second voltage, the grating structure rotates by a second set angle, wherein the first voltage is different from the second voltage, and the first set angle is different from the second set angle.

[0017] Optionally, the micro motor structure may also include a first modulation electrode and a second modulation electrode;

[0018] The strain beam structure includes a first compressive strain beam and a second compressive strain beam;

[0019] The first end of the first compressive strain beam is connected to the first modulation electrode, and the second end of the first compressive strain beam is connected to the grating structure; the first end of the second compressive strain beam is connected to the second modulation electrode, and the second end of the second compressive strain beam is connected to the grating structure.

[0020] The vertical projection of the line connecting the first endpoint and the second endpoint onto the substrate passes through the vertical projection of the center of the grating structure onto the substrate; the vertical projection of the line connecting the third endpoint and the fourth endpoint onto the substrate passes through the vertical projection of the center of the grating structure onto the substrate; wherein, the first endpoint is the endpoint where the first compressive strain beam is connected to the first modulation electrode, the second endpoint is the endpoint where the second compressive strain beam is connected to the second modulation electrode, the third endpoint is the endpoint where the first compressive strain beam is connected to the grating structure, and the fourth endpoint is the endpoint where the second compressive strain beam is connected to the grating structure.

[0021] When there is a voltage difference between the first modulation electrode and the second modulation electrode, the lengths of the first compressive strain beam and the second compressive strain beam simultaneously extend or shorten on a plane parallel to the first surface.

[0022] Optionally, the dimensions of the first compressive strain beam are the same as those of the second compressive strain beam.

[0023] Optionally, the outer contour of the grating structure projected vertically onto the substrate is an axisymmetric figure.

[0024] Optionally, the first end of the first compressive strain beam is rigidly connected to the first modulation electrode, and the second end of the first compressive strain beam is flexibly connected to the grating structure.

[0025] The first end of the second compressive strain beam is rigidly connected to the second modulation electrode, and the second end of the second compressive strain beam is flexibly connected to the grating structure.

[0026] Optionally, the grating structure includes high-contrast grating units;

[0027] The thickness and period of the high-contrast grating unit are both at the subwavelength level.

[0028] Optionally, the size of the grating structure is the same as the size of the oxide aperture;

[0029] The outer contour of the grating structure projected vertically onto the substrate coincides with the outer contour of the oxide aperture projected vertically onto the substrate.

[0030] Optionally, the shape of the outer contour of the vertical projection of the grating structure onto the substrate is the same as the shape of the outer contour of the vertical projection of the oxide aperture onto the substrate.

[0031] According to one aspect of the present invention, a method for fabricating a vertical-cavity surface-emitting laser is provided, comprising:

[0032] Provide substrate;

[0033] A first reflective layer is formed on one side of the substrate;

[0034] An active region is formed on the side of the first reflective layer away from the substrate;

[0035] A second reflective layer is formed on the side of the active region away from the first reflective layer;

[0036] An oxide layer is formed within a first reflective layer or a second reflective layer, wherein the oxide layer is adjacent to the active region and includes oxide pores;

[0037] A support layer is formed on the first surface of the second reflective layer, wherein the support layer includes vias; the first surface is the surface of the second reflective layer away from the active region, and the vertical projection of the vias on the substrate covers the vertical projection of the oxide apertures on the substrate.

[0038] A micro-motor structure is formed on the side of the support layer away from the second reflective layer; wherein, the micro-motor structure includes a grating structure and a strain beam structure; the grating structure is suspended on the side of the second reflective layer away from the active region through the strain beam structure; the vertical projection of the grating structure on the substrate overlaps with the vertical projection of the oxide aperture on the substrate; when the micro-motor structure is energized, the strain beam structure drives the grating structure to rotate on a plane parallel to the first surface.

[0039] This embodiment provides a vertical-cavity surface-emitting laser (VCSEL), which includes a substrate, a first reflective layer, an active region, a second reflective layer, an oxide layer located within the first or second reflective layer, a support layer, and a microelectromechanical system (MEMS) structure located on one side of the support layer. The MEMS structure includes a grating structure and a strain beam structure. The grating structure is suspended from the second reflective layer on the side away from the active region via the strain beam structure. When the MEMS structure is energized, the strain beam structure drives the grating structure to rotate in a plane parallel to the first surface of the second reflective layer. Since the extension direction of the grating in the grating structure can control the type of polarized light emitted, when the grating structure rotates, the extension direction of the grating changes, thereby changing the polarization type of the light emitted from the grating structure, achieving tunable polarization. In summary, the VCSEL provided in this embodiment can achieve polarization control.

[0040] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 This is a schematic diagram of a vertical cavity surface-emitting laser according to Embodiment 1 of the present invention;

[0043] Figure 2 yes Figure 1 A schematic diagram of the cross-sectional structure;

[0044] Figure 3 This is a top view of the structure of another vertical cavity surface-emitting laser provided in Embodiment 1 of the present invention;

[0045] Figure 4 This is a flowchart of a method for fabricating a vertical cavity surface-emitting laser according to Embodiment 2 of the present invention. Detailed Implementation

[0046] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0047] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0048] Example 1

[0049] This invention provides a vertical cavity surface-emitting laser. Figure 1 This is a schematic diagram of a vertical cavity surface-emitting laser according to Embodiment 1 of the present invention. Figure 2 yes Figure 1 A schematic diagram of the cross-sectional structure. Figure 2 The cross-sectional view in the middle can be along Figure 1 Obtained by cutting the section lines H1H2 in the reference. Figure 1 and Figure 2The vertical cavity surface-emitting laser includes: a substrate 10; a first reflective layer 20 located on one side of the substrate 10; an active region 30 located on the side of the first reflective layer 20 away from the substrate 10; a second reflective layer 40 located on the side of the active region 30 away from the first reflective layer 20; an oxide layer 50 located within the first reflective layer 20 or the second reflective layer 40, the oxide layer 50 being adjacent to the active region 30, and the oxide layer 50 including an oxide aperture 51; and a support layer 60 located on a first surface of the second reflective layer 40, the support layer 60 including a through-hole 61, wherein the first surface is the surface of the second reflective layer 40 away from the active region 30, and the vertical projection of the through-hole 61 on the substrate 10 covers the vertical projection of the oxide aperture 51 on the substrate 10. The micro-motor structure 70 is located on the side of the support layer 60 away from the second reflective layer 40. The micro-motor structure 70 includes a grating structure 71 and a strain beam structure 72. The grating structure 71 is suspended on the side of the second reflective layer 40 away from the active region 30 by the strain beam structure 72. The vertical projection of the grating structure 71 on the substrate 10 overlaps with the vertical projection of the oxide aperture 51 on the substrate 10. When the micro-motor structure 70 is energized, the strain beam structure 72 drives the grating structure 71 to rotate on a plane parallel to the first surface.

[0050] Specifically, the vertical-cavity surface-emitting laser (VCSEL) further includes a first electrode 81 and a second electrode 82. The first electrode 81 can be located on the side of the substrate 10 away from the first reflective layer 20, and the second electrode 82 can be located on the side of the second reflective layer 40 away from the active region 30 and surround the support layer 60. The second electrode 82 can be seamlessly adjacent to the support layer 60, and the material of the support layer 60 can be an insulating material. When the first electrode 81 and the second electrode 82 are energized, the VCSEL can emit laser light. The substrate 10 can be a gallium arsenide substrate or a sapphire substrate, etc. The first reflective layer 20 can be an n-type Bragg mirror, and the second reflective layer 40 can be a p-type Bragg mirror.

[0051] By configuring the vertical projection of the via 61 on the substrate 10 to overlap with the vertical projection of the oxide aperture 51 on the substrate 10, light emitted from the oxide aperture 51 can exit through the via 61. Furthermore, by configuring the vertical projection of the grating structure 71 on the substrate 10 to overlap with the vertical projection of the oxide aperture 51 on the substrate 10, light emitted from the oxide aperture 51 can pass through the grating structure 71 for exit, thereby enabling the grating structure 71 to perform polarization selection on the light emitted from the oxide aperture 51.

[0052] The grating structure 71 includes a plurality of gratings 75 arranged sequentially at intervals, with air between adjacent gratings 75. The grating structure 71 rotates in a plane parallel to the first surface, meaning that the distance between the grating structure 71 and the first surface of the second reflective layer 40 remains unchanged when the grating structure 71 rotates.

[0053] When the micro-motor structure 70 is energized, the strain beam structure 72 drives the grating structure 71 to rotate. As the grating structure 71 rotates, multiple gratings 75 within it rotate simultaneously, changing their extension directions. This change in the extension directions of the gratings 75 alters the polarization selectivity of the grating structure 71 towards light. Therefore, the polarization selectivity of the grating structure 71 after rotation differs from that before rotation. Since the grating structure 71 can rotate at different angles depending on the voltage received by the micro-motor structure 70, it is possible to modulate light with various polarizations.

[0054] It should be noted that in this embodiment, one grating structure 71 can correspond to one oxide aperture 51 (that is, a one-to-one correspondence between the light-emitting unit and the grating structure 71). When the vertical-cavity surface-emitting laser includes multiple oxide apertures 51, the extension direction of the grating 75 in the grating structure 71 corresponding to each oxide aperture 51 can be different, thereby achieving optical polarization modulation of a single light-emitting aperture. Alternatively, one grating structure 71 can correspond to multiple oxide apertures 51 (that is, one grating structure 71 corresponds to multiple light-emitting units), which can achieve optical polarization modulation of a single light-emitting area.

[0055] This embodiment provides a vertical-cavity surface-emitting laser (VCSEL) comprising a substrate 10, a first reflective layer 20, an active region 30, a second reflective layer 40, an oxide layer located within the first or second reflective layer 20, a support layer 60, and a microelectromechanical system (MEMS) structure 70 located on one side of the support layer. The MEMS structure 70 includes a grating structure 71 and a strain beam structure 72. The grating structure 71 is suspended from the second reflective layer 40 on the side away from the active region 30 via the strain beam structure 72. When the MEMS structure 70 is energized, the strain beam structure 72 drives the grating structure 71 to rotate in a plane parallel to the first surface of the second reflective layer 40. Since the extension direction of the grating 75 in the grating structure 71 can control the type of polarized light emitted, when the grating structure 71 rotates, the extension direction of the grating changes, thereby changing the polarization type of the light emitted from the grating structure 71, achieving tunable polarization. In summary, the VCSEL provided in this embodiment can achieve polarization control.

[0056] Optionally, when the micro motor structure receives a first voltage, the grating structure rotates by a first set angle; when the micro motor structure receives a second voltage, the grating structure rotates by a second set angle, wherein the first voltage and the second voltage are different, and the first set angle and the second set angle are different.

[0057] Specifically, by applying different voltages to the micro-motor structure, the strain beam structure can drive the grating structure to rotate at different angles, thereby achieving modulation of various polarized light. For example, when the micro-motor structure receives a 5V voltage, the grating structure can rotate 10° clockwise; when the micro-motor structure receives a 10V voltage, the grating structure can rotate 20° clockwise; and when the micro-motor structure receives a -10V voltage, the grating structure rotates 20° counterclockwise.

[0058] Optional, continue to refer to Figure 1 and Figure 2 The micro motor structure 70 also includes a first modulation electrode 731 and a second modulation electrode 732; the strain beam structure 72 includes a first compressive strain beam 721 and a second compressive strain beam 722; the first end of the first compressive strain beam 721 is connected to the first modulation electrode 731, and the second end of the first compressive strain beam 721 is connected to the grating structure 71; the first end of the second compressive strain beam 722 is connected to the second modulation electrode 732, and the second end of the second compressive strain beam 722 is connected to the grating structure 71. The vertical projection of the line connecting the first endpoint A and the second endpoint B onto the substrate 10 passes through the vertical projection of the center of the grating structure 71 onto the substrate 10; the vertical projection of the line connecting the third endpoint C and the fourth endpoint D onto the substrate 10 passes through the vertical projection of the center of the grating structure 71 onto the substrate 10; wherein, the first endpoint A is the endpoint where the first compressive strain beam 721 connects to the first modulation electrode 731, the second endpoint B is the endpoint where the second compressive strain beam 722 connects to the second modulation electrode 732, the third endpoint C is the endpoint where the first compressive strain beam 721 connects to the grating structure 71, and the fourth endpoint D is the endpoint where the second compressive strain beam 722 connects to the grating structure 71; when there is a voltage difference between the first modulation electrode 731 and the second modulation electrode 732, the lengths of the first compressive strain beam 721 and the second compressive strain beam 722 simultaneously extend or shorten on a plane parallel to the first surface.

[0059] Specifically, both the first modulation electrode 731 and the second modulation electrode 732 are located on the surface of the support layer 60 away from the second reflective layer 40. The first modulation electrode 731 and the second modulation electrode 732 are spaced apart. The first compressive strain beam 721 and the second compressive strain beam 722 can be suspended on the side of the second reflective layer 40 away from the active region 30.

[0060] The vertical projection of the line connecting the first endpoint A and the second endpoint B onto the substrate 10 passes through the vertical projection of the center of the grating structure 71 onto the substrate 10, and the vertical projection of the line connecting the third endpoint C and the fourth endpoint D onto the substrate 10 passes through the vertical projection of the center of the grating structure 71 onto the substrate 10. This allows the movement direction of the third endpoint C to be the same as the movement direction of the fourth endpoint D when the lengths of the first compressive strain beam 721 and the second compressive strain beam 722 change simultaneously.

[0061] The grating structure 71 is fixedly connected to the first modulation electrode 731 and the second modulation electrode 732 via a first compressive strain beam 721 and a second compressive strain beam 722. Both the first compressive strain beam 721 and the second compressive strain beam 722 are made of piezoelectric material. When a voltage is applied to the first modulation electrode 731 and the second modulation electrode 732, due to the inverse piezoelectric effect, the first compressive strain beam 721 and the second compressive strain beam 722 deform under the influence of the electric field due to induced polarization; that is, the lengths of the first compressive strain beam 721 and the second compressive strain beam 722 simultaneously extend or shorten. When the lengths of the first compressive strain beam 721 and the second compressive strain beam 722 change simultaneously, the grating structure 71 will rotate parallel to the first surface. For example, Figure 3 This is a top view of the structure of another vertical-cavity surface-emitting laser provided in Embodiment 1 of the present invention, with reference to... Figure 3 When the micro-motor structure receives the first voltage, the first compressive strain beam 721 and the second compressive strain beam 722 are in Figure 3 At the position indicated by the dashed line, when the micro-motor structure receives the second voltage, the first compressive strain beam 721 and the second compressive strain beam 722 are... Figure 3 The position is shown by the solid line. When the voltage received by the micro-motor structure changes from the first voltage to the second voltage, the first compressive strain beam 721 and the second compressive strain beam 722 shorten simultaneously. When the first compressive strain beam 721 and the second compressive strain beam 722 shorten simultaneously, the third endpoint C moves to position C1, and the fourth endpoint D moves to position D1. Since the grating structure 71 is fixedly connected to the first compressive strain beam 721 and the second compressive strain beam 722, when the first compressive strain beam 721 and the second compressive strain beam 722 shorten simultaneously, the grating structure 71 will rotate clockwise. The extension direction of the grating 75 in the rotated grating structure 71 changes, thereby changing the polarization type of the light emitted from the grating structure 71, realizing the characteristic of adjustable polarization.

[0062] It should be noted that the first compressive strain beam 721 and the second compressive strain beam 722 are parallel to the first plane. When the first compressive strain beam 721 and the second compressive strain beam 722 deform due to the compressive strain effect, they only elongate or shorten simultaneously on the plane parallel to the first surface, and the distance between the first compressive strain beam 721 and the second compressive strain beam 722 and the first surface remains constant. Furthermore, when the grating structure 71 rotates, the movement of the third endpoint C is relative to the first endpoint A, and the movement of the fourth endpoint D is relative to the second endpoint B. The grating structure 71 remains stationary relative to the connection point between the first compressive strain beam 721 and the grating structure 71, as well as the connection point between the second compressive strain beam 722 and the grating structure 71.

[0063] Optionally, the dimensions of the first compressive strain beam are the same as those of the second compressive strain beam.

[0064] Specifically, if the dimensions of the first and second compressive strain beams are different, the degree of change in the length of the first and second compressive strain beams will differ, potentially causing translational displacement of the grating structure during rotation. In this embodiment, the dimensions of the first and second compressive strain beams are the same, ensuring that the center position of the grating structure remains unchanged during rotation, thereby guaranteeing a constant light output.

[0065] Optionally, the outer contour of the grating structure projected vertically onto the substrate is an axisymmetric figure.

[0066] Specifically, axially symmetric figures can be circles, ellipses, or rectangles, etc.

[0067] Optional, continue to refer to Figure 3 The first end of the first compressive strain beam 721 is rigidly connected to the first modulation electrode 731, and the second end of the first compressive strain beam 721 is flexibly connected to the grating structure 71; the first end of the second compressive strain beam 722 is rigidly connected to the second modulation electrode 732, and the second end of the second compressive strain beam 722 is flexibly connected to the grating structure 71.

[0068] Specifically, a rigid connection can better secure the connection point between the first compressive strain beam 721 and the first modulation electrode 731, as well as the connection point between the second compressive strain beam 722 and the first modulation electrode 732. Since the first and second compressive strain beams 721 and 722 generate forces on the grating structure 71 when they deform, a rigid connection between them could easily cause the grating structure 71 to break. In this embodiment, the first and second compressive strain beams 721 and 722 are flexibly connected to the grating structure 71. Specifically, a buffer component can be provided between the first and second compressive strain beams 721 and the grating structure 71, and another buffer component can be provided between the second and second compressive strain beams 722 and the grating structure 71. The buffer component can be a conductive material with high deformation characteristics, thus mitigating the problem of the grating structure 71 breaking due to the buffering effect of the buffer component when the first and second compressive strain beams 721 and 722 deform.

[0069] Optional, continue to refer to Figure 3 The grating structure 71 includes a high-contrast grating unit 74; the thickness and period of the high-contrast grating unit 74 are both at the subwavelength level.

[0070] Specifically, the high-contrast grating unit (HCG) 74 is composed of multiple spaced gratings 75. The grating structure 71 can be the high-contrast grating unit 74, or it can be composed of the high-contrast grating unit 74 and a support structure. The support structure surrounds the high-contrast grating unit 74 and is used to connect the multiple gratings 75. The size of the support structure can be very small, and the area of ​​the high-contrast grating unit 74 is approximately the same as the area of ​​the grating structure 71.

[0071] The thickness and period of the high-contrast grating unit 74 are both on the subwavelength level, which can suppress higher-order transverse modes in the grating structure 71, allowing light with only the 0th order diffraction of the fundamental transverse mode to exit from the grating structure 71, and the exited light is in a single polarization state.

[0072] Optionally, the size of the grating structure is the same as the size of the oxide aperture; the outer contour of the vertical projection of the grating structure on the substrate coincides with the outer contour of the vertical projection of the oxide aperture on the substrate.

[0073] Specifically, if the size of the grating structure is larger than the size of the oxide aperture, the grating structure occupies a larger space, resulting in smaller sizes for the first and second compressive strain beams. If the lengths of the first and second compressive strain beams decrease, their range of variation will shrink, leading to a smaller rotation angle range for the grating structure. If the size of the grating structure is smaller than the size of the oxide aperture, some light emitted from the oxide aperture will be unable to pass through the grating structure, thus affecting the luminous efficiency. In this embodiment, the size of the grating structure is the same as the size of the oxide aperture, and the outer contour of the grating structure's vertical projection on the substrate coincides with the outer contour of the oxide aperture's vertical projection on the substrate. This ensures both the rotation range of the grating structure and the light extraction efficiency.

[0074] Optionally, the shape of the outer contour of the vertical projection of the grating structure onto the substrate is the same as the shape of the outer contour of the vertical projection of the oxide aperture onto the substrate.

[0075] Specifically, when the shape of the outer contour of the vertical projection of the grating structure onto the substrate is the same as the shape of the outer contour of the vertical projection of the oxide aperture onto the substrate, the grating structure can receive all the light emitted from the oxide aperture.

[0076] Example 2

[0077] This invention provides a method for fabricating a vertical-cavity surface-emitting laser (VCSEL) based on the above embodiments. Figure 4 This is a flowchart illustrating a method for fabricating a vertical-cavity surface-emitting laser according to Embodiment 2 of the present invention. (Refer to...) Figure 4 The method includes the following steps:

[0078] S110 provides a substrate.

[0079] S120. A first reflective layer is formed on one side of the substrate.

[0080] S130, an active region is formed on the side of the first reflective layer away from the substrate.

[0081] S140. A second reflective layer is formed on the side of the active region away from the first reflective layer.

[0082] S150. An oxide layer is formed in the first reflective layer or the second reflective layer, wherein the oxide layer is adjacent to the active region and the oxide layer includes oxide pores.

[0083] S160. A support layer is formed on the first surface of the second reflective layer, wherein the support layer includes a via; the first surface is the surface of the second reflective layer away from the active region, and the vertical projection of the via on the substrate covers the vertical projection of the oxide aperture on the substrate.

[0084] S170. A micro-motor structure is formed on the side of the support layer away from the second reflective layer; wherein, the micro-motor structure includes a grating structure and a strain beam structure; the grating structure is suspended on the side of the second reflective layer away from the active region through the strain beam structure; the vertical projection of the grating structure on the substrate overlaps with the vertical projection of the oxide aperture on the substrate; when the micro-motor structure is energized, the strain beam structure drives the grating structure to rotate on a plane parallel to the first surface.

[0085] The method for fabricating a vertical cavity surface-emitting laser provided in this embodiment has the same beneficial effects as the vertical cavity surface-emitting laser provided in any embodiment of the present invention. For technical details not covered in this embodiment, please refer to the vertical cavity surface-emitting laser provided in any embodiment of the present invention.

[0086] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0087] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A vertical-cavity surface-emitting laser, characterized in that, include: Substrate; The first reflective layer is located on one side of the substrate; The active region is located on the side of the first reflective layer away from the substrate; The second reflective layer is located on the side of the active region away from the first reflective layer; An oxide layer is located within the first reflective layer or the second reflective layer, the oxide layer is adjacent to the active region, and the oxide layer includes oxide pores; A support layer is located on a first surface of the second reflective layer. The support layer includes vias, wherein the first surface is the surface of the second reflective layer away from the active region, and the vertical projection of the vias onto the substrate covers the vertical projection of the oxide aperture onto the substrate. A micro-motor structure is located on the side of the support layer away from the second reflective layer. The micro-motor structure includes a grating structure and a strain beam structure. The grating structure is suspended from the second reflective layer away from the active region via the strain beam structure. The vertical projection of the grating structure on the substrate overlaps with the vertical projection of the oxide aperture on the substrate. The grating structure includes high-contrast grating units. The thickness and period of the high-contrast grating units are both at the subwavelength level. When the micro motor structure is energized, the strain beam structure drives the grating structure to rotate in a plane parallel to the first surface; The micro motor structure also includes a first modulation electrode and a second modulation electrode; The strain beam structure includes a first compressive strain beam and a second compressive strain beam; The first end of the first compressive strain beam is connected to the first modulation electrode, and the second end of the first compressive strain beam is connected to the grating structure; the first end of the second compressive strain beam is connected to the second modulation electrode, and the second end of the second compressive strain beam is connected to the grating structure. The vertical projection of the line connecting the first endpoint and the second endpoint on the substrate passes through the vertical projection of the center of the grating structure on the substrate; the vertical projection of the line connecting the third endpoint and the fourth endpoint on the substrate passes through the vertical projection of the center of the grating structure on the substrate; wherein, the first endpoint is the endpoint where the first compressive strain beam is connected to the first modulation electrode, the second endpoint is the endpoint where the second compressive strain beam is connected to the second modulation electrode, the third endpoint is the endpoint where the first compressive strain beam is connected to the grating structure, and the fourth endpoint is the endpoint where the second compressive strain beam is connected to the grating structure; When there is a voltage difference between the first modulation electrode and the second modulation electrode, the lengths of the first compressive strain beam and the second compressive strain beam simultaneously extend or shorten on a plane parallel to the first surface.

2. The vertical-cavity surface-emitting laser according to claim 1, characterized in that, When the micro motor structure receives the first voltage, the grating structure rotates by a first set angle. When the micro motor structure receives the second voltage, the grating structure rotates by a second set angle, wherein the first voltage is different from the second voltage, and the first set angle is different from the second set angle.

3. The vertical-cavity surface-emitting laser according to claim 1, characterized in that, The dimensions of the first compressive strain beam are the same as those of the second compressive strain beam.

4. The vertical-cavity surface-emitting laser according to claim 3, characterized in that, The outer contour of the grating structure as a vertical projection on the substrate is an axisymmetric figure.

5. The vertical-cavity surface-emitting laser according to claim 1, characterized in that, The first end of the first compressive strain beam is rigidly connected to the first modulation electrode, and the second end of the first compressive strain beam is flexibly connected to the grating structure. The first end of the second compressive strain beam is rigidly connected to the second modulation electrode, and the second end of the second compressive strain beam is flexibly connected to the grating structure.

6. The vertical-cavity surface-emitting laser according to claim 1, characterized in that, The size of the high-contrast grating unit is the same as the size of the oxide aperture; The outer contour of the vertical projection of the grating structure onto the substrate coincides with the outer contour of the vertical projection of the oxide aperture onto the substrate.

7. The vertical-cavity surface-emitting laser according to claim 1, characterized in that, The shape of the outer contour of the vertical projection of the grating structure onto the substrate is the same as the shape of the outer contour of the vertical projection of the oxide aperture onto the substrate.

8. A method for fabricating a vertical-cavity surface-emitting laser, characterized in that, include: Provide substrate; A first reflective layer is formed on one side of the substrate; An active region is formed on the side of the first reflective layer away from the substrate; A second reflective layer is formed on the side of the active region away from the first reflective layer; An oxide layer is formed within the first reflective layer or the second reflective layer, wherein the oxide layer is adjacent to the active region, and the oxide layer includes oxide pores; A support layer is formed on a first surface of the second reflective layer, wherein the support layer includes a via; the first surface is the surface of the second reflective layer away from the active region, and the vertical projection of the via on the substrate covers the vertical projection of the oxide aperture on the substrate; A micro-motor structure is formed on the side of the support layer away from the second reflective layer; wherein, the micro-motor structure includes a grating structure and a strain beam structure; the grating structure is suspended from the second reflective layer away from the active region via the strain beam structure; the vertical projection of the grating structure on the substrate overlaps with the vertical projection of the oxide aperture on the substrate; wherein, the grating structure includes a high-contrast grating unit; the thickness and period of the high-contrast grating unit are both at the subwavelength level; when the micro-motor structure is energized, the strain beam structure drives the grating structure to rotate in a plane parallel to the first surface; The micro motor structure also includes a first modulation electrode and a second modulation electrode; The strain beam structure includes a first compressive strain beam and a second compressive strain beam; The first end of the first compressive strain beam is connected to the first modulation electrode, and the second end of the first compressive strain beam is connected to the grating structure; the first end of the second compressive strain beam is connected to the second modulation electrode, and the second end of the second compressive strain beam is connected to the grating structure. The vertical projection of the line connecting the first endpoint and the second endpoint on the substrate passes through the vertical projection of the center of the grating structure on the substrate; the vertical projection of the line connecting the third endpoint and the fourth endpoint on the substrate passes through the vertical projection of the center of the grating structure on the substrate; wherein, the first endpoint is the endpoint where the first compressive strain beam is connected to the first modulation electrode, the second endpoint is the endpoint where the second compressive strain beam is connected to the second modulation electrode, the third endpoint is the endpoint where the first compressive strain beam is connected to the grating structure, and the fourth endpoint is the endpoint where the second compressive strain beam is connected to the grating structure; When there is a voltage difference between the first modulation electrode and the second modulation electrode, the lengths of the first compressive strain beam and the second compressive strain beam simultaneously extend or shorten on a plane parallel to the first surface.

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