Surface emitting laser

Abstract

The embodiment of the invention relates to a surface emitting laser. The surface emitting laser comprises a substrate; the bottom reflector structure, the active layer and the top reflector structure are arranged on the substrate; the photoelectric limiting layer is formed in the top reflecting mirror structure, and the photoelectric limiting layer comprises a light emitting aperture used for limiting the surface emitting laser; the far-field image adjusting layer is arranged on the top reflecting mirror structure; the far-field image adjusting layer comprises a base layer and an adjusting and controlling layer obtained by etching at least part of the area, located in the light-emitting aperture, of the base layer, and a far-field image formed after adjustment of the adjusting and controlling layer is a flat-top far-field image. According to the invention, the output of the flat-topped far-field image is realized in a photoelectric separation mode.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the technical field of semiconductor lasers, and particularly to a surface emitting laser. BACKGROUND

[0002] With the continuous development of semiconductor technology, surface emitting lasers, such as vertical cavity surface emitting lasers (VCSEL), are widely used in optical communication, optical interconnection and optical sensing due to their easy integration characteristics.

[0003] At present, there is a huge market demand for flat-top infrared (IR) illumination projection modules in many intelligent devices such as smart phones, which play a crucial role in specific applications such as TOF measurement, security camera devices, and vertical cavity surface emitting lasers (VCSEL) are the most core devices in flat-top infrared illumination projection modules.

[0004] The existing methods for forming flat-top far-field images, such as integrated diffusers or designing light-emitting holes, need to be further improved. SUMMARY

[0005] Therefore, it is necessary to provide a surface emitting laser to solve the above technical problems.

[0006] In a first aspect, the present application provides a surface emitting laser, comprising: a substrate; a bottom mirror structure, an active layer and a top mirror structure disposed on the substrate; a photoelectric confinement layer formed in the top mirror structure, the photoelectric confinement layer comprising a light-emitting aperture for defining the surface emitting laser; a far-field image adjusting layer disposed on the top mirror structure; the far-field image adjusting layer comprises a base layer and a regulation layer obtained by etching at least part of the base layer within the light-emitting aperture, and the far-field image formed after the regulation layer is adjusted is a flat-top far-field image.

[0007] In one embodiment, the photoelectric confinement layer comprises any one of an air column type photoelectric confinement layer, an oxidation confinement type photoelectric confinement layer, an ion implantation type photoelectric confinement layer and a tunnel junction type photoelectric confinement layer.

[0008] In one embodiment, the projection shape of the etched area on the substrate is a polygon, and at least two sides of the polygon are recessed towards the interior of the polygon.

[0009] In one embodiment, the polygon comprises a regular polygon or an irregular polygon.

[0010] In one of the embodiments, the regular polygon is a rectangle, and the short side of the rectangle is recessed towards the inside of the rectangle; or the long side of the rectangle is recessed towards the inside of the rectangle; or both the long side and the short side of the rectangle are recessed towards the inside of the rectangle.

[0011] In one of the embodiments, at least two sides are recessed towards the inside of the polygon to different degrees.

[0012] In one of the embodiments, the projection shape of the recess on the substrate is a circular arc, a rectangle or a triangle.

[0013] In one of the embodiments, the thickness of the control layer remaining after etching is an integer multiple of a quarter wavelength.

[0014] In one of the embodiments, the far-field image adjustment layer is arranged on the top mirror structure, or the far-field image adjustment layer is part of the top mirror structure.

[0015] In one of the embodiments, the material of the far-field image adjustment layer is selected from any one of silicon dioxide, silicon nitride and gallium arsenide.

[0016] The surface emitting laser described above makes the far-field image after regulation a flat-top far-field image by arranging a far-field image adjustment layer on the light emitting surface, and the far-field image adjustment layer is regulated by etching the area within the light emitting aperture range of the surface emitting laser to obtain a control layer. Compared with the traditional packaging integration, the photoelectric separation design avoids the problems of excessive overall volume of the module caused by the traditional packaging integration and the current concentration caused by the concave light emitting aperture.

[0017] In a second aspect, the application provides a VCSEL chip, comprising at least one laser array; the laser array comprises a plurality of surface emitting lasers as described above; the laser array is a regular arrangement array, or a random arrangement array, or an array with a plurality of addressable sub-arrays.

[0018] In a third aspect, the application provides a light source for a laser radar system, comprising at least one surface emitting laser as described above or at least one VCSEL chip as described above.

[0019] In a fourth aspect, the application provides a laser radar system, comprising a transmitting assembly and a receiving assembly, and the transmitting assembly uses the light source for a laser radar system as described above. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1A structure schematic diagram of a surface emitting laser in an embodiment of the present application; Figures 2a-2d A structure schematic diagram of a surface emitting laser in an embodiment of the present application; Figure 1 A structure schematic diagram of a surface emitting laser in an embodiment of the present application; Figure 3 A structure schematic diagram of a surface emitting laser in an embodiment of the present application.

[0021] The purposes, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0022] In order to make the purposes, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0023] It can be understood that the terms "first", "second", etc. used in the present application can be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from another element. For example, without departing from the scope of the present application, the first client can be referred to as the second client, and similarly, the second client can be referred to as the first client.

[0024] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. The meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise explicitly and specifically limited. The meaning of "several" is at least one, such as one, two, etc., unless otherwise explicitly and specifically limited.

[0025] Based on this, please refer to Figures 1-3 The present application provides a surface emitting laser, comprising: a substrate 10; a bottom mirror structure 20, an active layer 30 and a top mirror structure 40 arranged on the substrate 10; a photoelectric confinement layer (not shown in the figure) formed in the top mirror structure 40, the photoelectric confinement layer comprising a light emitting aperture OA for defining the surface emitting laser; a far field image adjusting layer 50 arranged on the top mirror structure 40; the far field image adjusting layer 50 comprising a base layer 510 and a regulation layer (not shown in the figure) obtained by etching at least part of the area EA of the base layer 510 within the light emitting aperture OA, the far field image formed after the regulation layer is adjusted is a flat top far field image.

[0026] In the specific embodiments, please refer to Figure 1 andFigure 3 The bottom mirror structure 20 and the top mirror structure 40 define a resonant cavity structure of the surface emitting laser of the present application, i.e. the area between the bottom mirror structure 20 and the top mirror structure 40 is the resonant cavity. The resonant cavity is used to generate a standing wave, which is a wave formed by two coherent waves traveling in opposite directions along the same line and superimposing on each other. Specifically, when the two waves have the same phase, their amplitudes are added to form a wave crest (i.e. a wave peak). When the two waves have opposite phases, their amplitudes are subtracted to form a wave trough (i.e. a wave valley). Therefore, the positions of the wave crest and the wave trough of the standing wave are fixed.

[0027] In one embodiment, the bottom mirror structure 20 can include a periodic stacked DBR structure, i.e. a plurality of mirrors with an optical thickness of one quarter of the lasing wavelength, and the plurality of mirrors are arranged alternately with high and low refractive indexes. The top mirror structure 40 also includes a periodic stacked DBR structure, i.e. a plurality of mirrors with an optical thickness of one quarter of the lasing wavelength, and the plurality of mirrors are arranged alternately with high and low refractive indexes. It can be understood that the components and the number of stacked periods of the DBR structure of the bottom mirror structure 20 and the DBR structure of the top mirror structure 40 can be the same or different, which is not limited in the present embodiment. The materials of the top mirror structure 40 and the bottom mirror structure 20 can be dielectric materials with electrical insulation, for example, can include silicon nitride, silicon oxide, aluminum oxide or titanium oxide, etc. The materials of the top mirror structure 40 and the bottom mirror structure 20 can also be semiconductor materials, for example, can include GaAs and AlGaAs.

[0028] The material of the substrate 10 includes but is not limited to GaAs, InP, Si, etc. The bottom mirror structure 20 and the top mirror structure 40 can include a film layer with periodically varying refractive index to achieve high efficiency reflection or transmission of light in a specific wavelength range. The film layer with periodically varying refractive index can be composed of semiconductor materials, dielectric materials, metal-dielectric hybrid materials, etc. For example, the bottom mirror structure 20 can be an N-type semiconductor layer, and the top mirror structure 40 can be a P-type semiconductor layer. For another example, the bottom mirror structure 20 can be a P-type semiconductor layer, and the top mirror structure 40 can be an N-type semiconductor layer. Alternatively, the materials of the N-type semiconductor layer and the P-type semiconductor layer can be but are not limited to GaAs, AlGaAs, etc., which are not limited herein, as long as the resonant cavity can be limited, which belongs to the protection scope of the present embodiment. Specifically, the resonant cavity structure can further include a photoelectric confinement layer, which is formed in the top mirror structure 40, and the photoelectric confinement layer defines a light region.

[0029] The active layer 30 can include one active region, two active regions, three active regions, or four active regions. Each active region can include one or more multiple quantum well structures. The multiple quantum well structure is used to generate photons of stimulated radiation, and the emitted photons are repeatedly reflected in the resonant cavity defined by the bottom mirror structure 20 and the top mirror structure 40, and are repeatedly enhanced in the process of reflection, so that the final laser light is emitted at a specific wavelength and has sufficient energy.

[0030] The multiple quantum well structure is the place where laser gain amplification occurs, and the center position of the multiple quantum well structure can be aligned with the position of the strongest light field to achieve greater amplification effect. Further, in the case of including multiple multiple quantum well structures, the confinement factor of the multiple quantum well structures in the same light field is within the same predetermined range, that is, the confinement factors of the multiple quantum well structures are maintained at the same level, so that each multiple quantum well structure contributes similarly to light emission. It can be understood that similar light emission contribution means that the current is more uniformly injected in each multiple quantum well structure, which helps to reduce the threshold current of the device, thereby reducing the power consumption of the device and prolonging its service life. Moreover, when each multiple quantum well structure contributes similarly to light emission, the distribution of carriers in each multiple quantum well structure will be more uniform, which helps to reduce the loss of carrier recombination, thereby improving the overall light emission efficiency of the device.

[0031] Generally, the number of photoelectric confinement layers is not greater than the number of active layers 30, for example, it can be 2, 3, 4, etc. The photoelectric confinement layer is used to limit the light emitting area of the surface emitting laser. Specifically, the photoelectric confinement layer is located on the side of the corresponding active layer 30 away from the substrate 10 to limit the flow of current, so that the current only flows in the light emitting area defined by the photoelectric confinement layer, thereby reducing unnecessary energy consumption, and further reducing the threshold current and improving the current density. Moreover, the photoelectric confinement layer can also confine the light field in the light emitting area defined by the photoelectric confinement layer, reducing the scattering and diffraction of light, thereby optimizing the divergence angle of the device and improving the beam quality. Generally, the photoelectric confinement layer is arranged at the position of the lowest light field intensity, that is, at the trough of the standing wave, so that it has a smaller confinement factor, thereby helping to reduce the divergence angle of the device.

[0032] The photoelectric confinement layer can include any one of an air column type photoelectric confinement layer, an oxidation confinement type photoelectric confinement layer, an ion implantation type photoelectric confinement layer, and a tunnel junction type photoelectric confinement layer. Among them, the air column type photoelectric confinement layer realizes the restriction of current and light through an air column, which is a hollow structure formed by dry etching technology, and has a lower refractive index than the surrounding semiconductor material, thereby effectively confining the light in the central region. The ion implantation type photoelectric confinement layer changes the electrical properties of the semiconductor material by implanting ions into it to form a high resistance region, which can restrict the flow of current and thereby indirectly restrict the light generation area.

[0033] In one embodiment, the oxidation-limited photoelectric confinement layer includes an unoxidized region of AlGaAs material with high Al component and an oxidized region of aluminum oxide material, the oxidized region is disposed outside the unoxidized region, and the unoxidized region forms a light emitting region for effective current injection. In the photoelectric confinement layer, the semiconductor layer in the unoxidized region can be understood as an opening (OA) for defining a light emitting region of the surface emitting laser. When current enters, the current can only flow to the active layer 30 through the opening in the photoelectric confinement layer, thereby achieving the limitation of current injection path and optical mode field. Further, the high Al component AlGaAs layer can be converted into aluminum oxide through a selective oxidation process to form the peripheral unoxidized region. Figures 2a-2d

[0034] In one embodiment, the tunnel junction type photoelectric confinement layer includes at least one high-doped N-type structure layer and at least one high-doped P-type structure layer. Specifically, the high-doped N-type structure layer and the high-doped P-type structure layer form a potential barrier therebetween, and allow electrons to pass through the potential barrier by tunneling effect, thereby achieving lateral limitation of current. In one embodiment, the materials of the N-type structure layer and the P-type structure layer are selected as AlGaAs, and the doping concentration of the N-type structure layer and the P-type structure layer is greater than 1e x cm 1-x x 18 cm -3 , where 0≤x≤1.

[0035] In one embodiment, as shown in FIG. 1, the projection shape of the etched region EA on the substrate 10 can be a polygon, and at least two sides of the polygon are recessed towards the interior of the polygon. In this embodiment, the polygon can be, for example, a quadrilateral, a pentagon, a hexagon, a heptagon, an octagon, etc., which are not limited by the present application. Further, the polygon of the present application can include a regular polygon or an irregular polygon. The regular polygon can be a square, a rectangle, a regular pentagon, a regular hexagon, etc., and the irregular polygon can be a diamond shape, an asymmetric hexagon, an asymmetric heptagon, etc., which are not limited by the present application. Figures 1-2d Further, when the regular polygon is a rectangle, two short sides of the rectangle can be recessed towards the interior of the rectangle, or two long sides of the rectangle can be recessed towards the interior of the rectangle, or both the two long sides and the two short sides of the rectangle can be recessed towards the interior of the rectangle.

[0036] Figure 2a As shown in FIG. 2, both the two long sides and the two short sides of the rectangle are recessed towards the interior of the rectangle.

[0037] ​​In one embodiment, the recesses (not shown in the figure) are circular arc-shaped, rectangular or triangular in shape when projected on the substrate 10. At the same time, at least two sides are recessed to different degrees towards the interior of the polygon. As shown, the recesses are circular arc-shaped, the polygon is rectangular, and the long and short sides of the rectangle are recessed to different degrees. Figure 2a The recesses are circular arc-shaped, the polygon is rectangular, and the long and short sides of the rectangle are recessed to different degrees. By recessing the peripheral areas (the long and short sides of the rectangle) of the convergent etching area EA to different degrees, the light intensity distribution in the final far field is a flat-top far field, i.e., a uniform light intensity distribution. Further, the recesses can also be triangular Figure 2b ) or semicircular Figure 2c ) or rectangular Figure 2d . In this concept, the shape of the recesses can also be other representations.

[0038] In one embodiment, the thickness of the control layer remaining after etching is an integer multiple of a quarter wavelength to meet the light emission requirements.

[0039] In one embodiment, the far field image adjustment layer 50 is provided on the top mirror structure, or the far field image adjustment layer 50 is part of the top mirror structure 40. For example, when the far field image adjustment layer 50 is provided on the top mirror structure 40, the material of the far field image adjustment layer 50 can be silicon dioxide, silicon nitride, aluminum trioxide, a polymer dielectric, or another type of dielectric material; when the far field image adjustment layer 50 is part of the top mirror structure 40, the material of the far field image adjustment layer 50 can be gallium arsenide or indium phosphide, etc. Further, when the far field image adjustment layer 50 is a dielectric material, the dielectric material is a layer that at least partially insulates the top metal 610 from one or more other layers or features (e.g., the sidewalls of the trench).

[0040] The surface emitting laser described above makes the far field image after its control a flat-top far field image by providing a far field image adjustment layer on the light emitting surface, and the far field image adjustment layer is controlled by etching the area within the light emitting aperture range of the surface emitting laser to obtain a control layer. Compared with the conventional packaging integration that leads to an excessively large overall volume of the module and the problem of current concentration caused by the concave light emitting aperture, the photoelectric separation design avoids these problems.

[0041] In one embodiment, to achieve the required high reflectivity, a reflectivity supplemental structure (not shown) can also be additionally designed, which is configured to increase the reflectivity on the side of the surface-emitting laser including the bottom mirror structure 20 (e.g., the top side of the surface-emitting laser). Without the reflectivity supplemental structure, the efficiency of integrating an optical element (such as a grating) in a surface-emitting laser on top of a semiconductor DBR mirror is lower (e.g., compared to a top-emitting surface-emitting laser) due to the required high reflectivity, and the reduced interaction of the cavity mode with the optical element. Reducing the number of mirror pairs in the top mirror structure 40, however, increases the coupling of the cavity mode to such an optical element. But, reducing the number of mirror pairs in the top mirror structure 40 reduces the reflectivity in the side of the surface-emitting laser including the top mirror structure. In a surface-emitting laser, the reflectivity supplemental structure is used to increase the reflectivity in the side of the surface-emitting laser including the bottom mirror structure 20. Thus, the number of mirror pairs in the bottom mirror structure 20 can be reduced, and the reflectivity supplemental structure can be designed to mitigate the reduction in reflectivity caused by the reduction in the number of mirror pairs in the bottom mirror structure 20. In some implementations, the reflectivity supplemental structure can include a plurality of DBR pairs or another type of mirror structure. In some implementations, the reflectivity supplemental structure is formed of a dielectric material. Thus, in some implementations, the reflectivity supplemental structure includes a plurality of dielectric DBR pairs. For example, the reflectivity supplemental structure can include a plurality of Si02 / SiNx mirror pairs, a plurality of Si02 / titanium dioxide (Ti02) mirror pairs, or a plurality of Al203 / Ti02 mirror pairs, among other examples. In some implementations, the thickness of the reflectivity supplemental structure can be in a range from about 2.0 pm to about 4.0 pm, such as 2.5 pm. In some implementations, the number of mirror pairs in the reflectivity supplemental structure is in a range from three mirror pairs to eight mirror pairs.

[0042] Figure 3 In some implementations, the surface-emitting laser can also include a top metal 610, which is a top metal layer at the front side of the surface-emitting laser. In some implementations, the top metal 610 can be a layer that is in electrical contact with the top mirror structure 40 (e.g., through a via in the far-field image adjustment layer and the top mirror structure 40). In some implementations, the top metal 610 can be used as an anode for the surface-emitting laser. In some implementations, the top metal 610 can include a plating metal (e.g., gold (Au)) and / or a seed metal used in a plating process.

[0043] In one of the embodiments, to achieve better ohmic contact, an ohmic contact metal (not shown) can also be formed on the surface of the top mirror structure 40. The ohmic contact metal is a top contact layer of the surface emitting laser that is in electrical contact with the top mirror structure 40 through which electrical current can flow. In some implementations, the ohmic contact metal is formed of a material optimized for contacting p-type semiconductors. Alternatively, in some implementations, the ohmic contact metal can also be formed of a material optimized for contacting n-type semiconductors. In some implementations, the ohmic contact metal has a thickness in a range from about 0.2 pm to about 0.8 pm, such as 0.5 pm. In some implementations, the ohmic contact metal has a ring shape, a slotted ring shape, a cog shape, or another type of circular or non-circular shape (e.g., depending on the design of the surface emitting laser).

[0044] Figure 3 In some implementations, the surface emitting laser can also include a bottom metal 620 that is a bottom metal layer underneath the surface emitting laser. In some implementations, the bottom metal 620 can be a layer that is in full-area electrical contact with the substrate 10. In some implementations, the bottom metal 620 can be used as a cathode for the surface emitting laser. In some implementations, the bottom metal 620 can include a plated metal (e.g., gold (Au)) and / or a seed metal used in a plating process.

[0045] Further, the surface emitting laser can also include a proton implant region (not shown) that is a region that prevents free carriers from reaching the edges of the trench and / or isolates adjacent surface emitting lasers from each other (e.g., if the trench does not fully enclose the surface emitting laser) and / or prevents free carriers from leaking from the sidewalls. The proton implant region can include, for example, an ion-implanted material, such as a hydrogen / proton-implanted material or similar implant element, to reduce electrical conductivity.

[0046] Figure 3 The number, arrangement, thickness, order, symmetry, etc. of the layers shown are provided as examples. In practice, more, fewer, different, differently configured, or differently arranged layers can be included in the surface emitting laser than those shown. Figure 3 The surface emitting laser can include additional layers, fewer layers, different layers, differently configured layers, or differently arranged layers than those shown. For example, in some implementations, the surface emitting laser can include a semiconductor layer (e.g., one or more p-type layers) above the far-field image adjustment layer. As another example, in some implementations, the surface emitting laser can include an air interface above the far-field image adjustment layer. Additionally or alternatively, a set of layers (e.g., one or more layers) of the surface emitting laser can perform one or more functions described as being performed by another set of layers of the surface emitting laser, and any layer can include more than one layer.

[0047] The embodiment of the present application also provides a VCSEL chip, which comprises at least one laser array. The laser array comprises a plurality of surface emitting lasers as described above, and the laser array is a regularly arranged array, or a randomly arranged array, or an array with a plurality of addressable sub-arrays. Based on the surface emitting laser described above, the VCSEL chip of the embodiment has good performance in reliability.

[0048] The embodiment of the present application also provides a light source for a lidar system, which comprises at least one surface emitting laser as described above or at least one VCSEL chip as described above.

[0049] The embodiment of the present application also provides a lidar system, which comprises a transmitting assembly and a receiving assembly, and the transmitting assembly adopts the light source for a lidar system as described above.

[0050] The foregoing disclosure provides illustrations and descriptions, but is not intended to be exhaustive or to limit the embodiments to the precise form disclosed. Modifications and variations can be made in light of the above disclosure, or can be acquired from the practice of the embodiments. Moreover, any of the embodiments described herein can be combined, unless the foregoing disclosure explicitly provides reasons why one or more embodiments can not be combined.

[0051] Even if a particular combination of features is recited in the claims and / or disclosed in the specification, these combinations are not intended to limit the disclosure of the various embodiments. In fact, many of these features can be combined in ways that are not specifically recited in the claims and / or disclosed in the specification. Although each dependent claim listed below can directly depend on only one claim, the disclosure of the various embodiments includes each dependent claim in combination with every other claim in the claim set. As used herein, the phrase “at least one of a list of items” refers to any combination of these items, including single members. As an example, “at least one of: a, b, or c” is intended to cover a, b, c, a-b, a-c, b-c, and a-b-c, as well as any combination with multiples of the same item (e.g., a-a, a-a-a, a-b-a, a-a-b, a-a-c, x-y-z, etc.).

[0052] When a component or one or more components (e.g., a laser emitter or one or more laser emitters) is described or claimed as performing a particular operation or being configured to perform a particular operation, such language is used herein to broadly cover any manner in which the component performs or is configured to perform the operation. For example, unless otherwise explicitly stated (e.g., via use of “first component” and “second component” or other language distinguishing components in a claim), such language is intended to cover a single component performing or configured to perform all operations, a group of components performing or configured to perform all operations together, a first component performing or configured to perform a first operation and a second component performing or configured to perform a second operation, or any combination of components performing or configured to perform operations. For example, when a claim is in the form “one or more components configured to: perform X; perform Y; and perform Z,” the claim should be interpreted to mean “one or more components configured to perform X; one or more (possibly different) components configured to perform Y; and one or more (possibly also different) components configured to perform Z.”

[0053] No element, act, or instruction used herein should be construed as critical or essential unless explicitly described as such. Also, as used herein, the articles “a” and “an” are intended to include one or more items, and can be used interchangeably with “one or more.” Further, as used herein, the article “the” is intended to include one or more items referenced by the article “the” and can be used interchangeably with “the one or more.” Also, as used herein, the term “set” is intended to include one or more items (for example, related items, unrelated items, or a combination of related and unrelated items) and can be used interchangeably with “one or more.” Where only one item is intended, the phrase “only one” or similar language is used. Also, as used herein, the terms “has,” “have,” “having,” or the like are intended to be open-ended terms. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise. Also, as used herein, the term “or” is intended to be inclusive when used in a series and can be used interchangeably with “and / or,” unless explicitly stated otherwise (for example, if used in combination with “or else” or “solely”). Further, spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper,” and the like, can be used herein for ease of description to describe one element or feature’s relationship to another element(s) or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The devices can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

Claims

1. A surface emitting laser, characterized in that include: substrate; a bottom reflector structure, an active layer, and a top reflector structure disposed on the substrate; an optoelectronic confinement layer formed in the top reflector structure, the optoelectronic confinement layer including a light emitting aperture for confining the surface emitting laser; A far-field image adjustment layer is provided on the top reflector structure; the far-field image adjustment layer includes a base layer and an adjustment layer obtained by etching at least a portion of the base layer located within the light-emitting aperture, and the far-field image formed after adjustment by the adjustment layer is a flat-top far-field image.

2. The surface emitting laser according to claim 1, wherein The photoelectric confinement layer includes any one of an air column type photoelectric confinement layer, an oxidation confinement type photoelectric confinement layer, an ion implantation type photoelectric confinement layer and a tunnel junction type photoelectric confinement layer.

3. The surface emitting laser according to claim 1, wherein The projection shape of the etched area on the substrate is a polygon, and at least two sides of the polygon are concave toward the interior of the polygon.

4. The surface emitting laser according to claim 3, wherein The polygon includes a regular polygon or an irregular polygon.

5. The surface emitting laser according to claim 4, wherein The regular polygon is a rectangle, and the short side of the rectangle is concave toward the inside of the rectangle; or The long sides of the rectangle are recessed toward the interior of the rectangle; or The long sides and the short sides of the rectangle are both recessed toward the interior of the rectangle.

6. The surface emitting laser according to claim 3, wherein At least two sides are recessed to different degrees toward the interior of the polygon.

7. The surface emitting laser according to claim 3, wherein The projection shape of the recess on the substrate is an arc, a rectangle or a triangle.

8. The surface emitting laser according to claim 1, wherein The thickness of the regulating layer remaining after etching is an integer multiple of a quarter wavelength.

9. The surface emitting laser according to claim 1, wherein The far-field image adjustment layer is provided on the top reflector structure, or the far-field image adjustment layer is a part of the top reflector structure.

10. The surface emitting laser according to claim 1, wherein The material of the far-field image adjustment layer is selected from any one of silicon dioxide, silicon nitride, and gallium arsenide.

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