WO2022193076A1 - Vertical-cavity surface-emitting laser and electronic device - Google Patents

Abstract

Provided are a vertical-cavity surface-emitting laser and an electronic device. The vertical-cavity surface-emitting laser comprises: a substrate, and a second reflector, a second isolation layer, an active layer, a first isolation layer and a first reflector which are sequentially stacked on the substrate, wherein a resonant cavity is defined between the second reflector and the first reflector; the first reflector comprises a first grating layer and a first transparent conducting layer which are mutually stacked, and the refractive index of the material of the first grating layer is larger than that of the material of the first transparent conducting layer; the first reflector has a light emitting region for emitting a laser; and both the first transparent conducting layer and the first grating layer at least cover the light emitting region. By means of the present application, the series resistance of the device can be reduced, the heat generation of the device can be reduced, and the thermal stability and the reliability of the device can be improved.

Description

Vertical Cavity Surface Emitting Laser and Electronic Equipment technical field

The present application relates to the technical field of semiconductor lasers, and in particular, to a vertical cavity surface emitting laser and electronic equipment.

Background technique

Vertical-Cavity Surface-Emitting Laser (VCSEL) is a new type of semiconductor laser emitting element with low threshold current, low cost, low power consumption, small divergence angle, and high coupling efficiency with fiber, which can realize High modulation rate, easy to mass-array production and testing and other excellent features. VCSELs were the first to be applied in the field of optical communications, and will be widely used in the Internet of Things, 5G communications, advanced driving systems and other fields in the future.

The existing vertical cavity surface emitting laser is usually composed of three or five compound semiconductor materials. Referring to FIG. 1, the vertical cavity surface emitting laser 80 includes: a lower distributed Bragg reflector 82 (Distributed Bragg Reflector, DBR) stacked on a substrate 81 in sequence. ), an n-type isolation layer 83 , an active region 84 , a p-type isolation layer 85 and an upper DBR 86 . Among them, DBR is formed by stacking multiple pairs of high and low refractive index 1/4 wavelength optical thickness films. In addition, a ring-shaped upper metal electrode 87 is also provided at the top edge of the upper DBR 86 , and a lower metal electrode 89 is also provided on the portion of the substrate 81 protruding from the package 88 . Further, a current confinement layer 90 is further provided in the upper distributed Bragg mirror 86 at a position close to the edge. The current confinement layer 90 has a ring-shaped structure as a whole and is located approximately directly below the upper metal electrode 87. The current confinement layer 90 A cylindrical current flow channel K may be formed at the center of the upper DBR 86, the active region 84, the lower DBR 82, etc., and the positions of the upper metal electrode 87 and the current flow channel K in the device thickness direction staggered from each other.

However, in the above-mentioned vertical cavity surface emitting laser, the device current is injected into the active region through the DBR and injected into the current flow channel defined by the annular current confinement layer, which will introduce a large series resistance and increase the heat generation of the device. , resulting in poor thermal stability and reliability of the device.

SUMMARY OF THE INVENTION

The present application provides a vertical cavity surface emitting laser and an electronic device, the series resistance of the device is small, and the thermal stability and reliability of the device are better.

A first aspect of the present application provides a vertical cavity surface emitting laser, comprising: a substrate, and a second reflector, a second isolation layer, an active layer, a first isolation layer, and a first reflector that are sequentially stacked on the substrate A resonant cavity is defined between the second reflector and the first reflector; the first reflector includes a first grating layer and a first transparent conductive layer stacked on each other, and the refractive index of the material of the first grating layer is greater than that of the first reflector. The refractive index of the material of the transparent conductive layer; the first reflector has a light emitting area for the laser to emit; the light emitting area corresponds to the setting area of the active layer, and both the first transparent conductive layer and the first grating layer cover at least the light emitting area.

In a possible implementation manner, the orthographic projection of the active layer on the first transparent conductive layer is located in the setting area of the first transparent conductive layer, and the orthographic projection of the active layer on the first grating layer is located in the first grating In the setting area of the layer, the area on the first reflector that is directly opposite to the active layer is the light emitting area.

In a possible implementation manner, the orthographic projection of the first transparent conductive layer on the active layer is located in the setting area of the active layer, and the area on the first reflector facing the first transparent conductive layer is the light emitting area. In a possible implementation manner, the first transparent conductive layer is in direct contact with the first isolation layer, so that the current in the first transparent conductive layer is injected into the active layer through the first isolation layer.

In a possible implementation manner, the first transparent conductive layer is disposed on the side of the first isolation layer facing away from the second reflector, and the first grating layer is disposed on the side of the first transparent conductive layer facing away from the first isolation layer.

In a possible embodiment, the first transparent conductive layer is a continuous film layer.

In a possible implementation manner, the first reflector further includes a protective layer, the protective layer is arranged on the first transparent conductive layer and covers the first grating layer, and the refractive index of the material of the protective layer is lower than that of the first grating layer The refractive index of the material.

In a possible implementation manner, the first grating layer is disposed on the side of the first isolation layer facing away from the second reflector, and the first transparent conductive layer is disposed on the side of the first grating layer facing away from the first isolation layer.

The first grating layer includes a plurality of grating bodies arranged at intervals, the grating bodies form the grating ridges of the first grating layer, and the intervals between adjacent grating bodies form the grating valleys of the first grating layer.

In a possible implementation manner, the material of the grating body in the first grating layer is the same as the material of the first isolation layer.

In a possible implementation manner, the first transparent conductive layer is a continuous film layer, and the first transparent conductive layer covers the first grating layer.

In a possible implementation manner, the first transparent conductive layer is a hollow structure to form a plurality of conductive bodies arranged at intervals, and the conductive bodies correspond to the grating bodies one-to-one, so that a grating structure is formed in the first transparent conductive layer.

In a possible implementation manner, the first reflector further includes a protective layer, the protective layer is provided on the side of the first transparent conductive layer away from the active layer, and the refractive index of the material of the protective layer is lower than that of the material of the first grating layer the index of refraction.

In a possible implementation manner, a portion of the first transparent conductive layer that is not covered by the protective layer forms a first electrode portion, and the first electrode portion is used for electrical connection with an external circuit.

In a possible implementation manner, the refractive index of the material of the first grating layer is greater than or equal to 1.4 times the refractive index of the material of the protective layer, and the extinction coefficient of the first grating layer is less than 0.05.

In a possible implementation manner, the first grating layer is a subwavelength grating layer.

In a possible implementation manner, the material of the first transparent conductive layer has a resistivity lower than

5x10 ^-3 Ω·cm of non-metallic material; and/or the first transparent conductive layer has an extinction coefficient of less than 0.03 for the laser emitted by the vertical cavity surface emitting laser; and/or the first transparent conductive layer is for vertical cavity surface emission The absorption rate of the laser light emitted by the laser is less than 0.5%.

In a possible implementation manner, the material of the first transparent conductive layer is a transparent conductive oxide.

In a possible implementation manner, the first grating layer includes a plurality of grating bodies arranged at intervals, and the grating bodies are elongated; or the grating bodies are island-shaped, and the cross-sections of the island-shaped grating bodies are square, circular, One of the hexagons.

In a possible implementation manner, when the grating bodies are in the shape of islands, the grating bodies in each island shape are arranged in an array or in a honeycomb shape.

In a possible implementation manner, the refractive index of the material of the first grating layer is greater than or equal to 1.4 times of the refractive index of the material of the first transparent conductive layer, and the first grating layer is sensitive to the laser light emitted by the vertical cavity surface emitting laser , with an extinction coefficient less than 0.1.

In a possible implementation manner, the material of the first grating layer is at least one of silicon, gallium nitride, indium phosphide, molybdenum sulfide, and gallium phosphide.

In a possible implementation manner, the reflectivity of the second reflector to the laser light emitted by the vertical cavity surface emitting laser is higher than the reflectivity of the first reflector to the laser light emitted by the vertical cavity surface emitting laser.

In a possible implementation, the second reflector comprises a distributed Bragg reflector.

In a possible implementation manner, the second reflector includes a plurality of high-refractive-index material layers and a plurality of low-refractive-index material layers, the number of the high-refractive-index material layers is the same as the number of the low-refractive-index material layers, and each high The refractive index material layers and the low refractive index material layers are alternately stacked, and the number of the low refractive index material layers in the second reflector is 20-30 layers.

In a possible implementation manner, it further includes a substrate, a second conductive layer and a second electrode, the second conductive layer is stacked between the distributed Bragg reflector and the substrate, and the distributed Bragg reflector and the second electrode They are stacked on the second conductive layer spaced apart from each other, and the second electrodes are used for electrical connection with an external circuit.

In a possible implementation manner, the second reflector includes a second grating layer and a second transparent conductive layer formed on the second grating layer, and the refractive index of the material of the second grating layer is greater than that of the material of the second transparent conductive layer , the orthographic projection of the active layer on the second transparent conductive layer is located in the setting area of the second transparent conductive layer; and the orthographic projection of the active layer on the second grating layer is located in the setting area of the second grating layer Inside.

In a possible implementation manner, the second transparent conductive layer is in direct contact with the second isolation layer, so that the current in the active layer is injected into the second transparent conductive layer through the second isolation layer; and/or the active layer is in the first The orthographic projection on the second grating layer is located in the setting area of the second grating layer.

In a possible implementation manner, the second transparent conductive layer is disposed on the side of the second isolation layer facing away from the first reflector, and the second grating layer is disposed on the side of the second transparent conductive layer facing away from the second isolation layer.

In a possible implementation manner, the second reflector further includes a flat layer, and the flat layer is disposed on the side of the second transparent conductive layer facing away from the first reflector and covers the second grating layer.

In a possible embodiment, the refractive index of the material of the flattening layer is lower than the refractive index of the material of the second grating layer.

In a possible implementation manner, the refractive index of the material of the flat layer is less than 0.7 times the refractive index of the material of the second grating layer, and the flat layer has an extinction less than 0.1 for the laser light emitted by the vertical cavity surface emitting laser coefficient.

In a possible implementation manner, a substrate and a bonding layer are also included, and the bonding layer is disposed between the substrate and the flat layer and used for bonding the substrate and the flat layer.

In a possible implementation manner, the material of the bonding layer is metal or oxide.

In a possible implementation manner, an encapsulation part surrounding the second isolation layer, the active layer and the side of the first isolation layer is further included.

In a possible implementation manner, the cross-sectional shape of the active layer is any one of a square, a circle, a triangle, and a hexagon.

A second aspect of the present application provides an electronic device, including the above vertical cavity surface emitting laser.

The vertical cavity surface emitting laser and electronic device of the present application, the vertical cavity surface emitting laser includes: a substrate, and a second reflector, a second isolation layer, an active layer, a first isolation layer and a second reflector, a second isolation layer, an active layer, a first isolation layer and A first reflector, a resonant cavity is defined between the second reflector and the first reflector; the first reflector includes a first grating layer and a first transparent conductive layer that are stacked on each other, and the refractive index of the material of the first grating layer is The refractive index of the material of the first transparent conductive layer is greater than that of the first transparent conductive layer; the first reflector has a light-emitting area for the laser to emit; the light-emitting area corresponds to the setting area of the active layer, and both the first transparent conductive layer and the first grating layer cover at least light-emitting area. In the above solution, the first reflector includes a first grating layer and a first transparent conductive layer, and both the first transparent conductive layer and the first grating layer cover at least the light-emitting area, in other words, the setting area of the first transparent conductive layer and the first The range of the setting area of a grating layer is greater than or equal to the setting range of the light emitting area, and the light emitting area corresponds to the setting area of the active layer, and the injection current can be directly injected from the first transparent conductive layer to the active layer without detouring In the device, the flow path of the current is short, so the series resistance of the device can be reduced, the heat generation of the device can be reduced, and the thermal stability and reliability of the device can be improved.

Description of drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the accompanying drawings used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are some embodiments of the present application, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

1 is a cross-sectional view of a vertical cavity surface emitting laser provided by the prior art;

2a is a cross-sectional view of a structure of a vertical cavity surface emitting laser provided by an embodiment of the present application;

Fig. 2b is a schematic structural diagram of current flow in the vertical cavity surface emitting laser shown in Fig. 2a;

3a is a schematic diagram of a structure of a grating body in a vertical cavity surface emitting laser provided in Embodiment 1 of the present application;

3b is a schematic diagram of another structure of the grating body in the vertical cavity surface emitting laser provided in the first embodiment of the application;

3c is a schematic diagram of still another structure of a grating body in a vertical cavity surface emitting laser provided by an embodiment of the present application;

4a is a cross-sectional view of another structure of the vertical cavity surface emitting laser provided in the first embodiment of the application;

4b is a cross-sectional view of still another structure of the vertical cavity surface emitting laser provided in the first embodiment of the application;

5a is a top view of another structure of the vertical cavity surface emitting laser provided in the first embodiment of the application;

5b is a top view of another structure of the vertical cavity surface emitting laser provided in the first embodiment of the application;

5c is a top view of another structure of the vertical cavity surface emitting laser provided in the first embodiment of the application;

5d is a top view of another structure of the vertical cavity surface emitting laser provided in the first embodiment of the application;

6 is a cross-sectional view of the vertical cavity surface emitting laser provided by the second embodiment of the present application;

7 is a cross-sectional view of a vertical cavity surface emitting laser provided in Embodiment 3 of the present application;

8 is a cross-sectional view of the vertical cavity surface emitting laser provided by the fourth embodiment of the present application;

FIG. 9 is a schematic structural diagram of the first transparent conductive layer in the vertical cavity surface emitting laser according to the fourth embodiment of the present application.

Description of reference numbers:

80, 100, 200, 300, 400-vertical cavity surface emitting laser; 81, 6, 60, 207-substrate; 82-lower distributed Bragg mirror; 83-n-type isolation layer; 84-active region; 85- p-type isolation layer; 86-upper distributed Bragg mirror; 87-upper metal electrode; 88-encapsulation; 89-lower metal electrode; 90-current confinement layer;

101, 201 - the second reflector; 2 - the second isolation layer; 109, 209, 309, 409 - the active layer; 103, 303, 403 - the first isolation layer; 106, 306, 406 - the first reflector; 51, 351, 451 - the first grating layer; 51' - the subwavelength grating layer; 510, 511, 512, 513, 404 - the grating body; 52, 352, 452 - the first transparent conductive layer; 521 - the first conductive part 53, 353, 453 protective layer; 61-electrode; 7-encapsulation part; 91-second conductive layer; 911-second conductive part; 92-high refractive index material layer; 93-low refractive index material layer; 94- The second electrode; 95-distributed Bragg reflector;

202-second grating layer; 203-second transparent conductive layer; 204-flat layer; 205-bonding layer;

305-first electrode part; 405-conductor; 408-conductive structure.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments It is a part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

The existing vertical cavity surface emitting laser generally has the technical problem of large series resistance of the device. Specifically, as shown in FIG. 1 , the structure of the upper DBR 86 is multi-layered, that is, the upper DBR 86 is alternately composed of 20 pairs of high and low refractive index semiconductor materials whose optical thickness is a quarter wavelength. The growth layer is formed, and the optical feedback is realized by the periodic change of the refractive index, and the effect of high reflectivity and wide bandwidth of DBR is obtained. However, the upper DBR 86 is formed by stacking multiple pairs of film layers, which results in a relatively large series resistance in the DBR 86; further, in order to avoid affecting the light output, the upper metal electrode 87 is arranged as a ring and the upper metal electrode 87 and the current flow channel K defined by the current confinement layer 90 are staggered from each other. The device current on the upper metal electrode 87 is injected through the current flow channel K defined by the annular current confinement layer 90, that is, the current flow path is to pass from the upper metal electrode 87 at the edge to the current flow channel at the center. In the process of K, the current flow path is longer.

The present application is proposed to solve the above-mentioned problems. The present application replaces the upper distributed Bragg reflector in the prior art with a reflector with a grating layer. Compared with the stacked layers of the refractive index semiconductor material, in the reflector with the grating layer of the present application, the number of stacked film layers is less, so that the film thickness of the first reflector can be reduced to reduce the series resistance. In addition, when the carriers in the reflector are no longer holes, the effective mass of the carriers can also be reduced to reduce the series resistance. In addition, the range of the disposition area of the upper metal electrode is made to correspond to the disposition area of the active layer to reduce the length of the current flow path and increase the radial dimension of the current flow path, thereby reducing the series resistance of the device. Embodiments of the vertical cavity surface emitting laser and the electronic device of the present application will be described below with reference to the accompanying drawings.

Example 1

FIG. 2a is a cross-sectional view of a structure of a vertical cavity surface emitting laser provided by an embodiment of the present application, and FIG. 2b is a schematic structural diagram of current flow in the vertical cavity surface emitting laser shown in FIG. 2a. 2a and 2b, the vertical cavity surface emitting laser 100 according to the embodiment of the present application includes: a substrate 6, and a second reflector 101, a second isolation layer 2, and an active layer 109 stacked on the substrate 6 in sequence , the first isolation layer 103 and the first reflector 106, a resonant cavity is defined between the second reflector 101 and the first reflector 106; the first reflector 106 includes a first grating layer 51 and a first transparent In the conductive layer 52, the refractive index of the material of the first grating layer 51 is greater than the refractive index of the material of the first transparent conductive layer 52, and the current in the first transparent conductive layer 52 is injected into the active layer 109 through the first isolation layer 103; The reflector 106 has a light emitting area O for the laser to emit; the light emitting area O corresponds to the setting position of the active layer 109 .

The size of the light emitting area O is determined by the size and position of the current passing area in the active layer 109. Specifically, referring to FIG. 2b, the light emitting area O is the current flow channel L in the first reflector 106 and the active layer 109. right area.

In the embodiments of the present application, the grating is also called a diffraction grating, which is an optical element that uses the principle of multi-slit diffraction to disperse light (decompose it into a spectrum). In the above solution, the first reflector 106 includes the first grating layer 51 and the first transparent conductive layer 52, and both the first transparent conductive layer 52 and the first grating layer 51 cover at least the light exit area O, see the solid line in FIG. 2b As shown by the arrows, the injection current can be injected substantially vertically from the first transparent conductive layer 52 into the corresponding region of the active layer 109, so that the light-exiting region O generates the outgoing laser light. During this process, the injection current does not bypass , but is injected into the active layer 109 along the longitudinal direction of the laser, so the current flow path is shorter; therefore, the series resistance of the device can be reduced, the heat generation of the device can be reduced, and the thermal stability and reliability of the device can be improved.

In addition, as mentioned above, when the first reflector 106 is set as a reflector including the first grating layer 51, compared with the stack layer including more than 20 pairs of high and low refractive index semiconductor materials in the prior art DBR, In the first reflector 106 with the first grating layer of the present application, the number of stacked film layers is small, so the film thickness of the first reflector 106 is reduced, for example, the total thickness of the DBR reaches 3-4 microns, While the thickness of the first reflector 106 of the present application is less than 1 micrometer, for example, less than 500 nm, the series resistance is also reduced, thereby reducing the heat generation of the device and improving the thermal stability of the device.

In an optional embodiment, referring to FIG. 2 a , the setting range of the active layer 109 is smaller than that of the first transparent conductive layer 52 . Specifically, the orthographic projection of the active layer 109 on the first transparent conductive layer 52 is located in the setting area of the first transparent conductive layer 52, and the orthographic projection of the active layer 109 on the first grating layer 51 is located in the first grating layer 51 in the setting area. The current flow channel L corresponds to at least a partial area of the first transparent conductive layer 52, and at this time, the lateral dimension of the current flow channel L is the same as the lateral dimension (radial dimension) of the disposition area of the active layer 109, which is the same as that in the prior art. Compared with the lateral dimension of the current flow channel K being smaller than that of the active layer 109 region, the lateral dimension of the current flow channel becomes larger.

In another optional embodiment, the setting range of the active layer is larger than that of the first transparent conductive layer, and the orthographic projection of the first transparent conductive layer on the active layer is located in the setting area of the active layer. The area on the reflector facing the first transparent conductive layer is the light emitting area.

In the embodiments of the present application, the orthographic projection of the active layer 109 on the first transparent conductive layer 52 refers to a projection pattern obtained by projecting the active layer 109 along the thickness direction of the vertical cavity surface emitting laser 100 . The orthographic projection of the active layer 109 on the first transparent conductive layer 52 is located in the setting area of the first transparent conductive layer 52, which means that the orthographic projection pattern of the active layer 109 on the first transparent conductive layer 52 is located in the first transparent conductive layer 52. within the area where the conductive layer 52 is provided. Alternatively, when the vertical cavity surface emitting laser 100 is viewed from above, the first transparent conductive layer 52 covers the active layer 109 . Similarly, the orthographic projection of the active layer 109 on the first grating layer 51 is located in the setting area of the first grating layer 51, which means that the orthographic projection pattern of the active layer 109 on the first grating layer 51 is located in the first grating layer 51. 51 in the setting area. Alternatively, when the vertical cavity surface emitting laser 100 is viewed from above, the first grating layer 51 covers the active layer 109 .

It can be understood that the setting area of the first transparent conductive layer 52 refers to the area enclosed by the outer edge of the first transparent conductive layer 52 , that is, the area defined by the outer edge of the first transparent conductive layer 52 . The first transparent conductive layer 52 may be provided in the whole layer, that is, in the case where the first transparent conductive layer 52 is a continuous film layer; the first transparent conductive film layer may also be partially provided with through-holes. It should be noted that the above-mentioned continuous film layer refers to a state in which the film layer is always continuous within its range, that is, there is no discontinuous region in the film layer.

In FIG. 2a, the case where the transparent conductive layer is provided as a whole layer and is a continuous film layer is taken as an example for description. In the embodiment of the present application, referring to FIG. 2 a , the first transparent conductive layer 52 and the first grating layer 51 are sequentially disposed on the side of the first isolation layer 103 facing away from the second reflector 101 . That is, the first grating layer 51 is disposed on the side of the first isolation layer 103 facing away from the second reflector 101 , and the first transparent conductive layer 52 is disposed on the side of the first grating layer 51 facing away from the first isolation layer 103 .

As shown in FIG. 2a, the setting range of the first transparent conductive layer 52 is larger than the setting range of the active layer 109. Exemplarily, the vertical cavity surface emitting laser 100 further includes surrounding the second isolation layer 2, the active layer 109 and the The encapsulation part 7 on the side of the first isolation layer 103 . The first transparent conductive layer 52 may extend laterally to cover the top surface of the encapsulation part 7 .

As mentioned above, the encapsulation portion 7 is surrounded by the outer side of the active layer 109 . Therefore, in this embodiment, the shape of the current flow channel L is defined by the encapsulation portion 7 , and the shape of the current flow channel L is the same as that of the active layer 109 . correspond.

Referring to FIG. 1 of the prior art, the dashed arrows indicate the current flow paths. In the upper distributed Bragg mirror 86, the device current flows through the lateral flow of the device, and then flows along the longitudinal direction of the device, that is, the inflow current flows The channel K has been bent and detoured. Specifically, the flow of the device current starts from the upper metal electrode 87 arranged on the edge of the upper distributed Bragg mirror 86, and flows to the middle part to the current defined by the current confinement layer 90. The flow channel K enters the lower distributed Bragg mirror 82 , and the radial dimension of the current flow channel K is smaller than that of the active layer 84 . 2b, the device current enters the second reflector 101 from the first transparent conductive layer 52 directly through the current flow channel L without detouring, that is, the flow process omits the process of flowing laterally along the device. In addition, the current The radial dimension of the flow channel L is the same as that of the active layer 109 . It can be seen from this that in the vertical cavity surface emitting laser 100 shown in FIG. 2a and FIG. 2b, the current flow path is short, and the radial dimension of the current flow channel L is large, so the vertical cavity surface emitting laser of this embodiment The transmitter can reduce the series resistance of the device, reduce the heat generation of the device, and improve the thermal stability and reliability of the device.

Compared with the prior art, the first grating layer 51 adopts a transparent conductive film (the first transparent conductive layer 52) as the low refractive index layer used together with it, and the first transparent conductive layer 52 can also be used as a device electrode, which can realize The current is injected vertically into the cavity surface, which reduces the series resistance of the device, and does not need to use wet oxidation or ion implantation to form a current-limiting aperture, which greatly reduces the difficulty of the process. It can be understood that the first transparent conductive layer 52 here functions as the upper electrode of the vertical cavity surface emitting laser, and the second conductive layer 91 described below functions as the lower electrode of the vertical cavity surface emitting laser. The connection method between the upper electrode and the lower electrode and the external circuit can be determined according to the connection of the actual circuit.

In addition, referring to FIG. 1 , the ring-shaped, opaque upper metal electrode 87 functions as an upper electrode, cannot transmit light, but occupies a certain lateral dimension in the laser, while in the first reflector 106, due to the first transparent conductive layer 52 does not affect the light output of the laser. Therefore, compared with the prior art, the size of the prior art laser is larger in the case of the same size of the current flow channel. In other words, in the case of the same outer contour size of the laser, the size of the current flow channel in the present application can be larger, which can play a better lateral light field confinement effect, which is more conducive to reducing the laser threshold and improving the laser quantum efficiency and slope efficiency.

Further, referring to FIG. 2 a , the first transparent conductive layer 52 is in direct contact with the first isolation layer 103 , so that the current in the first transparent conductive layer 52 is injected into the active layer 109 through the first isolation layer 103 . As described above, the first transparent conductive layer 52 is in direct contact with the first isolation layer 103, which can further reduce the series resistance compared with the prior art in which the metal electrode is in contact with the isolation layer through a current spreading structure. In the example of FIG. 2 a , the first transparent conductive layer 52 directly covers the surface of the first isolation layer 103 .

In the embodiment of the present application, referring to FIG. 2b, as an optional implementation manner, the first grating layer 51 may be a sub-wavelength grating layer 51'. The subwavelength grating layer 51 ′ is made of a dielectric material with a high refractive index difference or a suspended high refractive index material, and can be used as the first reflector 106 of the vertical cavity surface emitting laser 100 . By adjusting the grating period T, the thickness H of the high refractive index material of the grating and the duty ratio of the grating (the ratio of the width W of the high refractive index material to the grating period T), the subwavelength grating layer 51 ′ can achieve a broadband reflectivity greater than 99%, and at the same time can Realize polarization selection and transverse mode selection. In addition, the use of the subwavelength grating layer 51 ′ can greatly reduce the thickness of the reflector, reduce the difficulty of epitaxial growth of the vertical cavity surface emitting laser 100 , and simultaneously realize polarization and transverse mode selection. In addition, the subwavelength grating layer 51 ′ can stabilize the polarization characteristics of the laser light, and at the same time realize a good single-transverse base film output, increase the peak field intensity of the laser light, and reduce the divergence angle. Finally, changing the DBR structure of the prior art to the sub-wavelength grating layer 51' structure can also reduce the overall thickness of the device and improve the heat dissipation performance of the device.

In this embodiment of the present application, the grating structure in the first grating layer 51 may be set according to actual needs. 3a is a schematic diagram of a structure of a grating body in a vertical cavity surface emitting laser provided by an embodiment of the present application, and FIG. 3b is a schematic diagram of another structure of a grating body in a vertical cavity surface emitting laser provided by an embodiment of the present application. 3c is a schematic diagram of still another structure of the grating body in the vertical cavity surface emitting laser provided by the embodiment of the present application.

Exemplarily, the first grating layer 51 includes a plurality of grating bodies 510 arranged at intervals. The grating bodies 510 may form grating ridges of the first grating layer 51 , and the intervals between adjacent grating bodies 510 form the gratings of the first grating layer 51 . Valley. The grating body may be in the shape of a long strip, and as shown in FIG. 3 a , the grating bodies 511 in each long strip shape are arranged parallel to each other and periodically.

In some other examples, the grating body can be formed in an island shape, and the cross section of the island-shaped grating body is one of a square, a circle, and a hexagon. As shown in FIG. 3b, the cross section of each grating body 512 is In a square shape, the plurality of grating bodies 512 are arranged in an array; or as shown in FIG. 3c , the cross-section of each grating body 513 is hexagonal, and the plurality of grating bodies 513 are arranged in a honeycomb shape.

In the embodiment of the present application, referring to FIG. 2 a , as a possible implementation manner, in order to protect the first reflector 106 , the first reflector 106 further includes a protective layer 53 , and the protective layer 53 is provided on the first transparent conductive layer 52 Or on the first grating layer 51 , and the refractive index of the material of the protective layer 53 is lower than the refractive index of the material of the first grating layer 51 .

The protective layer 53 covers the first transparent conductive layer 52 or the first grating layer 51 , and the protective layer 53 covers the first grating layer 51 , which means that the protective layer 53 covers the grating bodies 510 and covers between the grating bodies 510 The surrounding of the grating body 510 with a higher refractive index is filled with a protective layer 53 with a lower refractive index.

In this embodiment of the present application, the first isolation layer 103 may be a p-type isolation layer, and the second isolation layer 2 may be an n-type isolation layer. The active layer 109 is used for emitting laser light, which may include an indium gallium arsenide multiple quantum well layer or a single quantum well layer, and is used to form in the thickness direction of the vertical cavity surface emitting laser 100, that is, the direction perpendicular to the laser exit surface stable standing waves.

In this embodiment of the present application, the type of the second reflector 101 can be selected according to actual needs, and the second reflector 101 can include the second conductive layer 91. It should be noted that, in order to better match the first transparent conductive layer 52, The second conductive layer 91 may also be provided as a continuous film layer. Referring to FIG. 2 a , at the same time, in order to facilitate electrical connection, the second conductive layer 91 may include a second conductive portion 911 protruding from the package portion 7 . Similar to the second conductive layer 91 , the first transparent conductive layer 52 may include a first conductive portion 521 protruding from the protective layer 53 .

In this embodiment of the present application, the second reflector 101 may be a distributed Bragg reflector.

FIG. 4a is a cross-sectional view of another structure of the vertical cavity surface emitting laser provided by the embodiment of the present application. Referring to FIG. 4 a , the second reflector 101 may include a distributed Bragg reflector 95 .

Exemplarily, the distributed Bragg reflector 95 includes a plurality of high-refractive-index material layers 92 and a plurality of low-refractive-index material layers 93, the number of the high-refractive-index material layers 92 is the same as the number of the low-refractive-index material layers 93, and each The high-refractive-index material layers 92 and the low-refractive-index material layers 93 are alternately stacked, and the number of the low-refractive-index material layers 93 in the second reflector 101 is 20 to 30 layers. Here, the refractive index of the material of the high refractive index material layer 92 is greater than the refractive index of the material of the low refractive index material layer 93 . It can be understood that, the materials of the high-refractive index material layer 92 and the low-refractive index material layer 93 are both group III and V semiconductor materials. Moreover, the material doping of the high refractive index material layer 92 and the low refractive index material layer 93 are both p-doped or n-doped, and the thickness of each material layer is 1/4 of the wavelength of the outgoing laser light. In addition, the reflectivity of the second reflector 101 including the DBR structure is higher than that of the first reflector 106 when the wavelength of the outgoing laser is incident normally.

Wherein, the above-mentioned second conductive layer 91 may be disposed between the distributed Bragg reflector 95 and the substrate 6, and in addition, the distributed Bragg reflector 95 and the second electrode 94 are stacked on the second conductive layer 91 at intervals, The second conductive layer 91 and the second electrode 94 are electrically connected to each other, where the second electrode 94 is used for electrical connection with an external circuit. Exemplarily, the substrate 6 may be an intrinsic III-V substrate.

Fig. 4b is a cross-sectional view of still another structure of the vertical cavity surface emitting laser provided in the first embodiment of the application. The vertical cavity surface emitting laser shown in Fig. 4b is based on the vertical cavity surface emitting laser shown in Fig. 2a or Fig. 4a , so that the second transparent conductive layer is omitted from the second reflector 101, and the material of the substrate 60 can be a highly doped n-type substrate material, and the rest of the structure is similar to that shown in FIG. 2a or FIG. . With this arrangement, the current in the second reflector 101 can directly pass through the substrate 60 to reach the electrode 61 disposed on the backside of the substrate 60 .

Here, the highly doped n-type substrate material means that the substrate material is an n-doped substrate, and the doping concentration is greater than 1×10 ¹⁷ cm ⁻³ , so that the current directly penetrates the substrate 60 and reaches the backside of the substrate 60 . Electrode 61.

In the embodiment of the present application, as mentioned above, the first reflector 106 does not have a current confinement layer and does not require an oxidation process. Therefore, the cross-sectional shape of the current flow channel L can be set as required, that is, the Vertical cavity surface emitting lasers can realize light exit holes of any shape.

5a-5d are plan views of another structure of the vertical cavity surface emitting laser provided by the embodiment of the present application. Exemplarily, the cross-sectional shape of the active layer may be square, as shown in FIG. 5a; or, the cross-sectional shape of the active layer may be circular, as shown in FIG. 5b; or the cross-sectional shape of the active layer may be is triangular, as shown in FIG. 5c; alternatively, the cross-sectional shape of the active layer may be hexagonal, as shown in FIG. 5d. It can be understood that, as mentioned above, the whole of the vertical cavity surface emitting laser has no symmetry, so the polarization characteristics of the emitted laser light are relatively stable.

The parameter selection of each functional film layer is described below.

Exemplarily, the reflectivity of the second reflector 101 to the laser light emitted by the vertical cavity surface emitting laser 100 is higher than the reflectivity of the first reflector 106 to the laser light emitted by the vertical cavity surface emitting laser 100 . Exemplarily, the normal incidence reflectance of the first reflector 106 to the laser light emitted by the vertical cavity surface emitting laser 100 should be greater than 99%, and the absorption rate should be lower than 0.5%.

The material of the first transparent conductive layer 52 is a non-metallic material with a resistivity lower than 5× ^{10 −3} Ω·cm; and/or the laser light emitted by the first transparent conductive layer 52 to the vertical cavity surface emitting laser 100 has an extinction coefficient less than 0.03 and/or the absorption rate of the first transparent conductive layer 52 to the laser light emitted by the vertical cavity surface emitting laser 100 is lower than 0.5%.

In addition, in order not to affect the light emission of the vertical cavity surface emitting laser 100, optionally, the material of the first transparent conductive layer 52 may be a transparent conductive oxide. In addition, the refractive index of the material of the first transparent conductive layer 52 is much lower than that of the first grating layer 51, so it can be directly used as an electrode on the vertical cavity surface emitting laser 100.

Optionally, the material of the first transparent conductive layer 52 may be a transparent conductive oxide (TCO) such as indium tin oxide (ITO), aluminum doped zinc oxide (AZO).

In this embodiment of the present application, optionally, the refractive index of the material of the first grating layer 51 is greater than or equal to 1.4 times the refractive index of the material of the first transparent conductive layer 52 , and the first grating layer 51 emits light to the vertical cavity surface. The laser light emitted by the laser 100 has an extinction coefficient less than 0.1. And/or the material of the first grating layer 51 is at least one of silicon, gallium nitride, indium phosphide, molybdenum sulfide, and gallium phosphide.

Optionally, the refractive index of the material of the first grating layer 51 is greater than or equal to 1.4 times the refractive index of the material of the protective layer 53 . And the extinction coefficient of the first grating layer 51 is less than 0.05.

In this embodiment, the vertical cavity surface emitting laser includes: a substrate, and a second reflector, a second isolation layer, an active layer, a first isolation layer, and a first reflector that are sequentially stacked on the substrate. A resonant cavity is defined between the reflector and the first reflector; the first reflector includes a first grating layer and a first transparent conductive layer that are stacked on each other, and the refractive index of the material of the first grating layer is greater than that of the first transparent conductive layer The index of refraction of the material; the first reflector has a light emitting area for the laser to emit; the light emitting area corresponds to the setting area of the active layer, and both the first transparent conductive layer and the first grating layer cover at least the light emitting area. In the above solution, the first reflector includes a first grating layer and a first transparent conductive layer, and both the first transparent conductive layer and the first grating layer cover at least the light-emitting area, in other words, the setting area of the first transparent conductive layer and the first The range of the setting area of a grating layer is greater than or equal to the setting range of the light emitting area, and the light emitting area corresponds to the setting area of the active layer, and the injection current can be directly injected from the first transparent conductive layer to the active layer without detouring In the device, the flow path of the current is short, so the series resistance of the device can be reduced, the heat generation of the device can be reduced, and the thermal stability and reliability of the device can be improved.

Embodiment 2

The vertical cavity surface emitting laser 200 provided in this embodiment improves the structures of the second reflector and the substrate on the basis of the first embodiment, and the remaining parts are the same as those in the first embodiment. The detailed description is given in Embodiment 1, and details are not repeated here.

FIG. 6 is a cross-sectional view of the vertical cavity surface emitting laser according to the second embodiment of the present application. 6 , the second reflector 201 includes a second grating layer 202 and a second transparent conductive layer 203 formed on the second grating layer 202 . The refractive index of the material of the second grating layer 202 is greater than that of the second transparent conductive layer 203 The refractive index of the material, the orthographic projection of the active layer 209 on the second transparent conductive layer 203 is located in the setting area of the second transparent conductive layer 203 . And, the orthographic projection of the active layer 209 on the second grating layer 202 is located within the disposition area of the second grating layer 202.

Similar to the first embodiment, the second reflector 201 includes a second grating layer 202 and a second transparent conductive layer 203 , and the orthographic projection of the active layer 209 on the second transparent conductive layer 203 is located on the second transparent conductive layer 203 . In the setting area, in other words, the range of the setting area of the second transparent conductive layer 203 is greater than or equal to the setting range of the active layer 209, combined with the setting of the first transparent conductive layer 52 in the first implementation, the injection current can be injected from the active layer 209. Directly injected into the second transparent conductive layer 203, that is, the positions of the second transparent conductive layer 203, the first transparent conductive layer 52 and the current flow channel L in the device thickness direction correspond to each other, and the radial dimension of the active layer 209 is smaller than the radial dimension of the second transparent conductive layer 203 and the first transparent conductive layer 52, and the lateral dimension of the injection current flow channel L is the same as the lateral dimension of the setting area of the active layer 209, which is the same as the current flow in the prior art. Compared with the lateral dimension of the channel being smaller than that of the active layer region, the lateral dimension of the current flow channel L becomes larger, so the series resistance of the device can be reduced, the heat generation of the device can be reduced, and the thermal stability and reliability of the device can be improved.

The orthographic projection of the active layer 209 on the second transparent conductive layer 203 refers to a projection pattern obtained by projecting the active layer 209 along the thickness direction of the vertical cavity surface emitting laser. The orthographic projection of the active layer 209 on the second transparent conductive layer 203 is located in the setting area of the second transparent conductive layer 203, which means that the orthographic projection of the active layer 209 on the second transparent conductive layer 203 is located in the second transparent conductive layer 203. within the area where the conductive layer 203 is provided. Alternatively, when the vertical cavity surface emitting laser is viewed from above, the second transparent conductive layer 203 covers the active layer 209 .

It can be understood that the setting area of the second transparent conductive layer 203 refers to the area enclosed by the outer edge of the second transparent conductive layer 203 . It may include the case where the second transparent conductive layer 203 is provided in the whole layer, that is, the second transparent conductive layer 203 is a continuous film layer;

In this embodiment of the present application, optionally, the orthographic projection of the active layer 209 on the second grating layer 202 is located in the setting area of the second grating layer 202 . Even if the coverage area of the second grating layer 202 is greater than or equal to the disposition area of the active layer, the current flow channel L has a radial dimension as large as possible.

It should be noted that the material types of the second transparent conductive layer 203 and the requirements on the materials are the same as those of the first transparent conductive layer 52 , which will not be repeated here. Exemplarily, the second grating layer 202 may be a subwavelength grating. The material types and requirements for the second grating layer 202 are the same as those of the first grating layer 51 . Subwavelength grating refers to a periodic (or aperiodic) structure whose characteristic size is equal to or smaller than the working wavelength. The reflectivity, transmittance, polarization properties and spectral properties of subwavelength gratings are completely different from those of conventional diffractive optical elements. different characteristics.

In order to further reduce the series resistance, the second transparent conductive layer 203 can be in direct contact with the second isolation layer 2 , so that the current in the active layer 209 can be directly injected into the second transparent conductive layer 203 through the second isolation layer 2 .

Referring to FIG. 6 , exemplarily, the second transparent conductive layer 203 and the second grating layer 202 are sequentially disposed on the side of the second isolation layer 2 facing away from the first reflector 106 . Here, the grating structure in the second grating layer 202 may be the same as the structure in FIG. 3 a , FIG. 3 b , and FIG. 3 c in the first implementation, which will not be repeated here.

Further, the second reflector 201 further includes a flat layer 204. The flat layer 204 is disposed on the side of the second transparent conductive layer 203 facing away from the first reflector 106 and covers the second grating layer 202, that is, the flat layer 204 is to cover Each grating body in the second grating layer 202 also covers the spacing between the grating bodies.

It should be noted that the refractive index of the material of the flat layer 204 is lower than the refractive index of the material of the second grating layer 202 . Exemplarily, the refractive index of the material of the flat layer 204 is less than 0.7 times the refractive index of the material of the second grating layer 202, and the flat layer 204 has an extinction coefficient of less than 0.1 for the laser light emitted by the vertical cavity surface emitting laser.

In this embodiment of the present application, optionally, the vertical cavity surface emitting laser 200 further includes a substrate 207 and a bonding layer 205. The bonding layer 205 is disposed between the substrate 207 and the flat layer 204 and is used to make the substrate 207 and the flat layer 204 The flat layer 204 is bonded. Exemplarily, the material of the bonding layer 205 may be metal or oxide.

In this embodiment, the second reflector 201 includes a second grating layer 202 and a second transparent conductive layer 203 formed on the second grating layer 202 . The refractive index of the material of the second grating layer 202 is greater than that of the second transparent conductive layer 203 The refractive index of the material is , the orthographic projection of the active layer 209 on the second transparent conductive layer 203 is located in the setting area of the second transparent conductive layer 203 . In this way, the range of the setting area of the second transparent conductive layer 203 is greater than or equal to the setting range of the active layer 209. Combined with the setting of the first transparent conductive layer 52 in Implementation 1, the injection current can be directly injected from the active layer 209 to the first transparent conductive layer 209. Among the two transparent conductive layers 203, that is, the positions of the second transparent conductive layer 203, the first transparent conductive layer 52 and the current flow channel L in the device thickness direction correspond to each other, and the radial dimension of the active layer 209 is smaller than that of the second transparent conductive layer 52. The radial dimension of the layer 203 and the first transparent conductive layer 52, at this time, the lateral dimension of the injection current flow channel L is the same as the lateral dimension of the setting area of the active layer 209, which is smaller than the lateral dimension of the current flow channel in the prior art. Compared with the lateral size of the active layer region, the lateral size of the current flow channel becomes larger, so the series resistance of the device can be reduced, the heat generation of the device can be reduced, and the thermal stability and reliability of the device can be improved.

Embodiment 3

The vertical cavity surface emitting laser 300 provided in this embodiment improves the structure of the first reflector on the basis of Embodiment 1 and Embodiment 2, and the remaining parts are the same as those in Embodiment 1 and Embodiment 2. For the remaining parts, Since detailed descriptions have been made in Embodiment 1 and Embodiment 2, details are not repeated here.

FIG. 7 is a cross-sectional view of the vertical cavity surface emitting laser provided by the third embodiment of the present application. 7 , the first grating layer 351 and the first transparent conductive layer 352 are sequentially disposed on the side of the first isolation layer 303 facing away from the second reflector 101 . That is, the first grating layer 351 is disposed on the side of the first isolation layer 303 facing away from the second reflector 101 , and the first transparent conductive layer 352 is disposed on the side of the first grating layer 351 facing away from the first isolation layer 303 .

In the embodiment of the present application, the material of the first grating layer 351 is the same as the material of the first isolation layer 303 . In this way, the first grating layer 351 can be formed by etching the material for forming the first isolation layer 303 . That is, the first grating layer 351 and the first isolation layer 303 may be integrally formed. Of course, the first grating layer 351 and the first isolation layer 303 can also be formed separately by using different materials.

Optionally, the first transparent conductive layer 352 may be a continuous film layer, and the first transparent conductive layer 352 covers the first grating layer 351 . That is, the first transparent conductive layer 352 not only covers the tops of the grating bodies in the first grating layer 351, but also covers the gaps between the grating bodies. In this embodiment, the first transparent conductive layer 352 is a continuous film layer provided in the whole layer.

Similar to the first embodiment, the first reflector 306 also includes a protective layer 353 , and the protective layer 353 covers the side of the first transparent conductive layer 352 facing away from the active layer 309 . And the refractive index of the material of the protective layer 353 is lower than the refractive index of the material of the first grating layer 351 .

In addition, the first transparent conductive layer 352 also has a first electrode portion 305 not covered by the protective layer 353, and the first electrode portion 305 is used for electrical connection with an external circuit.

In this embodiment, the material of the first grating layer 351 is the same as the material of the first isolation layer 303 . In this way, the first grating layer 351 can be formed by etching the material used for forming the first isolation layer 303, the process is simple, and the cost can be saved.

Embodiment 4

The vertical cavity surface emitting laser 400 provided in this embodiment improves the structure of the first reflector on the basis of the third embodiment, and the remaining parts are the same as those in the third embodiment. description, which will not be repeated here.

FIG. 8 is a cross-sectional view of the vertical cavity surface emitting laser provided in the fourth embodiment of the present application. Referring to FIG. 8 , in the embodiment of the present application, the material of the first grating layer 451 is the same as the material of the first isolation layer 403 . In this way, the first grating layer 451 can be formed by etching the material for forming the first isolation layer 403 . That is, the first grating layer 451 and the first isolation layer 403 may be integrally formed. Of course, the first grating layer 451 and the first isolation layer 403 can also be formed of different materials and formed separately.

Optionally, the first grating layer 451 includes a plurality of grating bodies 404 arranged at intervals, and the first transparent conductive layer 452 is a hollow structure to form a plurality of conductive bodies 405 arranged at intervals, and the conductive bodies 405 and the grating bodies 404 are in one-to-one correspondence. , so that a grating structure is formed in the first transparent conductive layer 452 .

FIG. 9 is a schematic structural diagram of the first transparent conductive layer in the vertical cavity surface emitting laser according to the fourth embodiment of the present application.

Referring to FIG. 9 , it should be noted that in this embodiment, the structures of the grating body 404 and the conductors 405 can only be strip-shaped structures, and the conductors 405 are also electrically connected through a conductive structure 408 . Exemplarily, the conductors 405 are spaced apart and arranged in parallel, and the conductive structure 408 can be, for example, a frame-shaped member, which is arranged around the conductors 405 and used to electrically connect the two ends of the conductors 405 .

Similar to the first embodiment, the first reflector 406 also includes a protective layer 453 , and the protective layer 453 covers the side of the first transparent conductive layer 452 facing away from the active layer 409 . It should be noted that the protective layer 453 not only covers the conductors 405 , but also covers the intervals between the grating bodies 404 and the intervals between the conductors 405 . And the refractive index of the material of the protective layer 453 is lower than the refractive index of the material of the first grating layer 451 .

In this embodiment, the material of the first grating layer 451 is the same as the material of the first isolation layer 403 . In this way, the first grating layer 451 can be formed by etching the material used to form the first isolation layer 403, the process is simple, and the cost can be saved. In addition, the first transparent conductive layer 452 is formed into a hollow structure, and the conductors 405 are in one-to-one correspondence with the grating bodies 404, so that in addition to the first grating layer 451, another layer of grating is formed on the first grating layer 451. layer to make the performance of the first reflector 406 better.

Embodiment 5

An embodiment of the present application further provides an electronic device, including the vertical cavity surface emitting laser described in any one of the foregoing embodiments. The structure, function and principle of the vertical cavity surface emitting laser have been described in detail in Embodiments 1 to 4, and will not be repeated here.

Specifically, the electronic device may be an electronic product or component such as a mobile phone, a tablet computer, a TV, a notebook computer, a digital photo frame, and a fingerprint lock. By including the vertical cavity surface emitting laser, the electronic device can shorten the current flow path of the device and increase the radial size of the current flow channel, so the series resistance of the device can be reduced, the heat generation of the device can be reduced, and the thermal stability of the device can be improved. and reliability.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The technical solutions described in the foregoing embodiments can still be modified, or some or all of the technical features thereof can be equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the present application. scope.

Claims (36)

1. A vertical cavity surface emitting laser, comprising: a substrate, and a second reflector, a second isolation layer, an active layer, a first isolation layer, and a first reflection layer that are sequentially stacked on the substrate A resonant cavity is defined between the second reflector and the first reflector; the first reflector includes a first grating layer and a first transparent conductive layer stacked on each other, the first grating layer The refractive index of the material is greater than the refractive index of the material of the first transparent conductive layer; the first reflector has a light-emitting area for the laser to emit, and the light-emitting area corresponds to the setting position of the active layer;

   Both the first transparent conductive layer and the first grating layer cover at least the light emitting area.
2. The vertical cavity surface emitting laser according to claim 1, wherein,

   The orthographic projection of the active layer on the first transparent conductive layer is located in the setting area of the first transparent conductive layer, and the orthographic projection of the active layer on the first grating layer is located on the In the setting area of the first grating layer, the area on the first reflector facing the active layer is the light exit area.
3. The vertical cavity surface emitting laser according to claim 1, wherein,

   The orthographic projection of the first transparent conductive layer on the active layer is located in the setting area of the active layer, and the area on the first reflector facing the first transparent conductive layer is the light-emitting area.
4. The vertical cavity surface emitting laser according to claim 1, wherein,

   The first transparent conductive layer is in direct contact with the first isolation layer, so that the current in the first transparent conductive layer is injected into the active layer through the first isolation layer.
5. The vertical cavity surface emitting laser according to any one of claims 1-4, wherein,

   The first transparent conductive layer is disposed on the side of the first isolation layer away from the second reflector, and the first grating layer is disposed on the side of the first transparent conductive layer away from the first isolation layer superior.
6. The vertical cavity surface emitting laser according to claim 5, wherein,

   The first transparent conductive layer is a continuous film layer.
7. The vertical cavity surface emitting laser according to claim 5, wherein,

   The first reflector further includes a protective layer, the protective layer is arranged on the first transparent conductive layer and covers the first grating layer, and the refractive index of the material of the protective layer is lower than that of the first The refractive index of the material of the grating layer.
8. The vertical cavity surface emitting laser according to any one of claims 1-4, wherein,

   The first grating layer is disposed on the side of the first isolation layer away from the second reflector, and the first transparent conductive layer is disposed on the side of the first grating layer away from the first isolation layer .
9. The vertical cavity surface emitting laser according to claim 8, wherein,

   The first grating layer includes a plurality of grating bodies arranged at intervals, the grating bodies form the grating ridges of the first grating layer, and the intervals between the adjacent grating bodies form the grating valleys of the first grating layer .
10. The vertical cavity surface emitting laser according to claim 9, wherein,

    The material of the grating body in the first grating layer is the same as the material of the first isolation layer.
11. The vertical cavity surface emitting laser according to claim 10, wherein:

    The first transparent conductive layer is a hollow structure to form a plurality of conductive bodies arranged at intervals, and the conductive bodies are in one-to-one correspondence with the grating bodies, so that a grating structure is formed in the first transparent conductive layer.
12. The vertical cavity surface emitting laser according to claim 10, wherein:

    The first transparent conductive layer is a continuous film layer, and the first transparent conductive layer covers the tops of the plurality of grating bodies and covers the spaces between the plurality of grating bodies.
13. The vertical cavity surface emitting laser according to any one of claims 8-12, wherein,

    The first reflector further includes a protective layer, the protective layer is arranged on the side of the first transparent conductive layer away from the active layer, and the refractive index of the material of the protective layer is lower than that of the first grating The refractive index of the material of the layer.
14. The vertical cavity surface emitting laser according to claim 7 or 13, wherein,

    A portion of the first transparent conductive layer that is not covered by the protective layer forms a first electrode portion, and the first electrode portion is used for electrical connection with an external circuit.
15. The vertical cavity surface emitting laser according to claim 7 or 13, wherein,

    The refractive index of the material of the first grating layer is greater than or equal to 1.4 times the refractive index of the material of the protective layer, and the extinction coefficient of the first grating layer is less than 0.05.
16. The vertical cavity surface emitting laser according to any one of claims 1-15, wherein,

    The first grating layer is a subwavelength grating layer.
17. The vertical cavity surface emitting laser according to any one of claims 1-15, wherein,

    The material of the first transparent conductive layer is a non-metallic material with a resistivity lower than 5× ^{10 −3} Ω·cm; and/or

    The laser light emitted by the first transparent conductive layer to the vertical cavity surface emitting laser has an extinction coefficient less than 0.03; and/or

    The absorption rate of the first transparent conductive layer to the laser light emitted by the vertical cavity surface emitting laser is lower than 0.5%.
18. The vertical cavity surface emitting laser according to any one of claims 1-15, wherein,

    The material of the first transparent conductive layer is transparent conductive oxide.
19. The vertical cavity surface emitting laser according to any one of claims 1-15, wherein,

    The first grating layer includes a plurality of grating bodies arranged at intervals, and the grating bodies are elongated; or

    The first grating layer includes a plurality of grating bodies arranged at intervals, the grating bodies are island-shaped, and the cross-section of the island-shaped grating bodies is one of a square, a circle, and a hexagon.
20. The vertical cavity surface emitting laser according to claim 19, wherein,

    The grating bodies are in the shape of islands, and the grating bodies in each island shape are arranged in an array or in a honeycomb shape.
21. The vertical cavity surface emitting laser according to any one of claims 1-15, wherein,

    The refractive index of the material of the first grating layer is greater than or equal to 1.4 times the refractive index of the material of the first transparent conductive layer, and the first grating layer is used for the laser light emitted by the vertical cavity surface emitting laser, Has an extinction coefficient of less than 0.1.
22. The vertical cavity surface emitting laser according to any one of claims 1-15, wherein,

    The material of the first grating layer is at least one of silicon, gallium nitride, indium phosphide, molybdenum sulfide, and gallium phosphide.
23. The vertical cavity surface emitting laser according to any one of claims 1-15, wherein,

    The reflectivity of the second reflector to the laser light emitted by the vertical cavity surface emitting laser is higher than the reflectivity of the first reflector to the laser light emitted by the vertical cavity surface emitting laser.
24. The vertical cavity surface emitting laser according to any one of claims 1-23, wherein,

    It also includes a substrate and a second electrode, the second reflector is stacked on the substrate, the second electrode is stacked on a side of the substrate facing away from the second reflector, and the first reflector is stacked on the substrate. The two electrodes are used for electrical connection with external circuits.
25. The vertical cavity surface emitting laser according to any one of claims 1-23, wherein,

    The second reflector includes a distributed Bragg reflector.
26. The vertical cavity surface emitting laser according to claim 25, wherein:

    The second reflector includes a plurality of high refractive index material layers and a plurality of low refractive index material layers, the number of the high refractive index material layers is the same as the number of the low refractive index material layers, and each of the high refractive index material layers The low-refractive-index material layers and the low-refractive-index material layers are alternately stacked, and the number of the low-refractive-index material layers in the second reflector is 20-30 layers.
27. The vertical cavity surface emitting laser according to claim 25, wherein:

    Also includes a second conductive layer and a second electrode, the second conductive layer is stacked between the distributed Bragg reflector and the substrate, and the distributed Bragg reflector and the second electrode are spaced from each other The ground is laminated on the second conductive layer, and the second electrode is used for electrical connection with an external circuit.
28. The vertical cavity surface emitting laser according to any one of claims 1-23, wherein,

    The second reflector includes a second grating layer and a second transparent conductive layer formed on the second grating layer, and the refractive index of the material of the second grating layer is greater than that of the material of the second transparent conductive layer. refractive index,

    The orthographic projection of the active layer on the second transparent conductive layer is located in the setting area of the second transparent conductive layer, and the orthographic projection of the active layer on the second grating layer is located in the within the setting area of the second grating layer.
29. The vertical cavity surface emitting laser according to claim 28, wherein,

    The second transparent conductive layer is in direct contact with the second isolation layer, so that the current in the active layer is injected into the second transparent conductive layer through the second isolation layer.
30. The vertical cavity surface emitting laser according to claim 28 or 29, wherein,

    The second transparent conductive layer is disposed on the side of the second isolation layer away from the first reflector, and the second grating layer is disposed on the side of the second transparent conductive layer away from the second isolation layer superior.
31. The vertical cavity surface emitting laser of claim 30, wherein:

    The second reflector further includes a flat layer, the flat layer is disposed on the side of the second transparent conductive layer facing away from the first reflector, and covers the second grating layer.
32. The vertical cavity surface emitting laser of claim 31, wherein:

    The refractive index of the material of the flat layer is lower than the refractive index of the material of the second grating layer.
33. The vertical cavity surface emitting laser of claim 32, wherein:

    The refractive index of the material of the flat layer is less than 0.7 times the refractive index of the material of the second grating layer, and the flat layer has an extinction coefficient of less than 0.1 for the laser light emitted from the vertical cavity surface emitting laser .
34. The vertical cavity surface emitting laser of claim 31, wherein:

    Also included is a substrate and a bonding layer, the bonding layer being disposed between the substrate and the planarization layer and used to bond the substrate and the planarization layer.
35. The vertical cavity surface emitting laser according to any one of claims 1-33, wherein,

    The cross-sectional shape of the active layer is any one of square, circle, triangle, and hexagon.
36. An electronic device, characterized by comprising the vertical cavity surface emitting laser according to any one of claims 1-35.

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