CN110233423A - The high-power vertical cavity surface emitting laser of metal grill - Google Patents

Abstract

The present invention provides a metal grid high-power vertical cavity surface emitting laser, which has an emission hole and an upper electrode structure, and the upper electrode structure includes a peripheral electrode and a plurality of grid line electrodes, wherein the peripheral electrode is arranged on the The outer periphery of the emission hole, the plurality of grid electrodes are connected to the peripheral electrodes and extend into the emission hole. The present invention divides the vertical cavity surface emitting laser with large oxidation aperture into a plurality of narrow and long block regions by increasing the current path through a plurality of gate wire electrodes, on the one hand, it can effectively increase the vertical cavity surface emitting laser with large oxidation aperture The current density in the central region, on the other hand, the current can be transmitted laterally from the plurality of grid electrodes, which greatly improves the uniformity of the current density distribution in the light-emitting hole and improves the conversion efficiency. At the same time, the coherence of the outgoing light is maintained in a wide range. The invention can be applied in fields such as laser radar, infrared camera and depth recognition detector.

Description

Metal Grid High Power Vertical Cavity Surface Emitting Laser

technical field

The invention belongs to the field of semiconductor laser design and manufacture, in particular to a metal grid high-power vertical cavity surface emitting laser.

Background technique

Vertical cavity surface emitting laser (VCSEL) is developed on the basis of gallium arsenide semiconductor materials. It is different from other light sources such as light-emitting diodes (LEDs) and laser diodes (LDs). It has small size, circular output spot, and single longitudinal mode output. , small threshold current, low price, easy integration into large-area arrays, etc., are widely used in optical communication, optical interconnection, optical storage and other fields.

The Vertical Cavity Surface Emitting Laser (VCSEL) is a new type of laser that emits light from the vertical surface. Its different structure from the traditional edge emitting laser brings many advantages: small divergence angle and circular symmetrical far and near field distribution make it compatible with optical fiber The coupling efficiency is greatly improved without the need for complex and expensive beam shaping systems. It has been confirmed that the coupling efficiency with multimode fibers can be greater than 90%; The single longitudinal mode operation can be realized within a certain temperature range, and the dynamic modulation frequency is high; on-chip testing can be performed, which greatly reduces the development cost; the light output direction is perpendicular to the substrate, which can easily realize the integration of high-density two-dimensional area arrays and achieve higher Power output, and because multiple lasers can be arranged in parallel in the direction perpendicular to the substrate, it is very suitable for applications in the fields of parallel optical transmission and parallel optical interconnection. It has been successfully applied to single-channel and parallel lasers at an unprecedented speed Optical interconnection, with its high cost performance, has been widely used in broadband Ethernet and high-speed data communication networks; the most attractive thing is that its manufacturing process is compatible with light-emitting diodes (LEDs), and the cost of large-scale manufacturing very low.

Vertical-cavity surface-emitting lasers (VCSELs) are widely used in optical communications, optical storage, optical interconnection, optical computing, solid-state lighting, laser printing, and biosensing. In recent years, there have been larger-scale applications in emerging markets such as 3D face recognition, proximity sensors, lidar, infrared cameras, and depth detection. In many practical applications, it is required that the vertical cavity surface emitting laser (VCSEL) can achieve high energy density, and some also require the laser source to have a certain degree of coherence. Arraying the light-emitting apertures can increase the luminous power, but the energy density is limited by the spacing between the light-emitting points, and the coherence will be eliminated (good for some applications, others want to preserve coherence). Enlarging the oxide pore size is a simple and feasible solution to increase energy density while maintaining coherence. However, vertical-cavity surface-emitting lasers (VCSELs) with large oxide apertures face the problem of uneven current density distribution, resulting in low conversion power and poor consistency of light intensity distribution.

Contents of the invention

In view of the above-mentioned shortcomings of the prior art, the object of the present invention is to provide a metal grid high-power vertical cavity surface emitting laser, which is used to solve the problem of uneven current density distribution of the large oxide aperture vertical cavity surface emitting laser.

To achieve the above purpose and other related purposes, the present invention provides a metal grid high-power vertical cavity surface emitting laser, the vertical cavity surface emitting laser has an emission hole and an upper electrode structure, and the upper electrode structure includes peripheral electrodes and multiple A grid line electrode, wherein the peripheral electrode is arranged on the periphery of the emission hole, and the plurality of grid line electrodes are connected to the peripheral electrode and extend into the emission hole.

Optionally, the plurality of gate wire electrodes are connected to the peripheral electrodes at intervals and extend toward the center of the emission hole.

Optionally, the width of the gate line electrode gradually decreases from the peripheral electrode toward the interior of the emission hole.

Optionally, the upper electrode structure further includes several gate line connection electrodes, the gate line connection electrodes are arranged in the emission holes, and are connected to several of the plurality of gate line electrodes.

Optionally, the emission hole is a circular emission hole, the grid electrode extends from the peripheral electrode toward the center of the emission hole, the grid connection electrode is a ring-shaped grid connection electrode, and the The diameter of the ring-shaped grid wire connecting electrodes gradually decreases from the peripheral electrode toward the center of the emission hole, and each of the ring-shaped grid wire connecting electrodes is connected to the plurality of grid wire electrodes.

Optionally, the plurality of grid line electrodes are connected to the peripheral electrodes at intervals and arranged in parallel in the emission hole.

Optionally, the plurality of grid electrodes form a polarization structure, and by adjusting the distance between the plurality of grid electrodes, the degree of polarization of the outgoing light of the vertical cavity surface emitting laser can be adjusted.

Optionally, the distance between any two adjacent grid line electrodes ranges from 4 microns to 30 microns.

Optionally, the grid electrode has a width ranging from 0.1 micron to 2 microns, and a height ranging from 100 nanometers to 5 microns.

Optionally, the number of the grid line electrodes is not less than 2.

Optionally, the radial width of the emission hole is not less than 15 microns.

Optionally, the emission hole has a radial width ranging from 50 microns to 1000 microns.

Optionally, the plurality of grid wire electrodes form ohmic contacts with the substrate, the P-type conductive mirror or the N-type conductive mirror in the region of the emission hole of the vertical cavity surface emitting laser.

Optionally, the vertical cavity surface emitting laser is a front emitting structure, and the vertical cavity surface emitting laser further includes: a substrate, the back of the substrate has a lower electrode structure; an N-type conductive lower reflector located on the On the substrate; the active layer is located on the N-type conductive lower reflector; the P-type conductive upper reflector is located on the active layer, and the P-type conductive upper reflector has a current confinement layer , and the emission hole is defined by the current confinement layer; and a dielectric layer is located on the P-type conductive upper mirror; wherein, the plurality of grid electrodes pass through the dielectric layer and are connected to the P Type conductive upper mirror forms an ohmic contact.

Optionally, the gate electrode includes a stacked structure composed of a Ti layer, a Pt layer and an Au layer from bottom to top.

Optionally, the vertical cavity surface emitting laser is a back emitting structure, and the vertical cavity surface emitting laser further includes: a P-type conductive lower reflector, the back of the P-type conductive lower reflector has a lower electrode structure; Layer, located on the P-type conductive lower reflector; N-type conductive upper reflector, located on the active layer, the N-type conductive upper reflector has a current confinement layer, and is limited by the current A layer defines the emission hole; a substrate, located on the N-type conductive upper mirror; and a dielectric layer, formed on the substrate; wherein, the plurality of grid electrodes pass through the dielectric layer and Ohmic contacts are formed with the substrate.

Optionally, the grid line electrode includes a stacked structure composed of Au layer, Ge layer, Ni layer and Au layer from bottom to top.

Optionally, the vertical cavity surface emitting laser is a back emitting structure, and the vertical cavity surface emitting laser further includes: a P-type conductive lower reflector, the back of the P-type conductive lower reflector has a lower electrode structure; Layer, located on the P-type conductive lower reflector; N-type conductive upper reflector, located on the active layer, the N-type conductive upper reflector has a current confinement layer, and is limited by the current The layer defines the emission hole; the substrate is located on the N-type conductive upper reflector, and the substrate located in the region of the emission hole is removed to form an emission cavity to expose the N-type conductive upper reflector and a dielectric layer formed on the exposed N-type conductive upper reflector; wherein, the plurality of grid electrodes pass through the dielectric layer and form ohmic contact with the N-type conductive upper reflector.

Optionally, the grid line electrode includes a stacked structure composed of Au layer, Ge layer, Ni layer and Au layer from bottom to top.

Optionally, the current confinement layer includes one of an air column current confinement structure, an ion implantation current confinement structure, a buried heterojunction current confinement structure, and an oxidation-limitation current confinement structure.

The present invention also provides a laser radar. The light source of the laser radar adopts the above-mentioned vertical cavity surface emitting laser.

The present invention also provides an infrared camera, wherein the light source of the infrared camera adopts the above-mentioned vertical cavity surface emitting laser.

The present invention also provides a 3D depth recognition detector, the light source of the depth recognition detector adopts the above-mentioned vertical cavity surface emitting laser.

As mentioned above, the metal grid high-power vertical cavity surface emitting laser of the present invention has the following beneficial effects:

The present invention divides the vertical cavity surface emitting laser with large oxidation aperture into a plurality of narrow and long block-shaped regions by increasing the current path through a plurality of grid wire electrodes, on the one hand, it can effectively increase the vertical cavity surface emitting laser with large oxidation aperture The current density in the central region, on the other hand, the current can be transmitted laterally from the plurality of grid electrodes, which greatly improves the uniformity of the current density distribution in the luminescent hole and improves the conversion efficiency. Through the optimization of parameters such as line width and spacing, the conversion efficiency of the vertical cavity surface emitting laser of the present invention can reach 30-50%.

The above-mentioned multiple narrow and long block-shaped regions of the present invention are located in the same emission hole, have coherence, and can cooperate with diffractive optical elements (DOE), so that the signal-to-noise ratio of the vertical cavity surface emitting laser can be significantly improved. At the same time, the coherence of the outgoing light is maintained in a wide range. The invention can be applied in fields such as laser radar, infrared camera and depth recognition detector.

The grid line electrode of the present invention can realize the function of current injection and optical polarization at the same time, and can realize the optical polarization of the laser without adding additional optical elements, which can effectively reduce volume and cost. The structure and fabrication method of metal grid high power vertical cavity surface emitting laser.

The present invention can effectively improve the power density of the vertical cavity surface emitting laser, that is, the power per unit area of the laser or laser array is improved, and the number of lasers to be used can be reduced under the same optical power requirement, and the Improve the integration level of the chip and effectively reduce the cost of the chip.

Description of drawings

1 to 3 are schematic diagrams showing the upper electrode structure of the metal grid high-power vertical cavity surface emitting laser of the present invention.

4 to 5 are schematic structural diagrams of the metal grid high-power vertical cavity surface emitting laser in Embodiment 1 of the present invention.

FIG. 6 is a schematic structural diagram of a metal grid high-power vertical-cavity surface-emitting laser in Embodiment 2 of the present invention.

FIG. 7 is a schematic structural diagram of another metal grid high-power vertical-cavity surface-emitting laser in Embodiment 2 of the present invention.

8 to 9 are schematic diagrams showing the current injection distribution of the vertical cavity surface emitting laser of the present invention and the traditional metal grid high-power vertical cavity surface emitting laser, respectively.

10 to 11 are schematic structural diagrams of a metal grid high-power vertical cavity surface emitting laser in Embodiment 3 of the present invention.

Component designation description

100 embrasures

101 Peripheral electrodes

102 grid electrode

103 grid wire connection electrode

104 substrate

105 Bottom electrode structure

106 N type conductive lower reflector

107 active layer

108 P type conductive upper reflector

109 Current Limiting Layer

110 medium layer

111 Narrow and long blocky area

206 N type conductive upper reflector

208 P type conductive lower reflector

Detailed ways

Embodiments of the present invention are described below through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation modes, and various modifications or changes can be made to the details in this specification based on different viewpoints and applications without departing from the spirit of the present invention.

Please refer to Figure 1 to Figure 11. It should be noted that the diagrams provided in this embodiment are only schematically illustrating the basic idea of the present invention, so that only the components related to the present invention are shown in the diagrams rather than the number, shape and Dimensional drawing, the type, quantity and proportion of each component can be changed arbitrarily during actual implementation, and the component layout type may also be more complicated.

Example 1

As shown in Figures 1 to 5, this embodiment provides a metal grid high-power vertical cavity surface emitting laser. After research and analysis, the existing vertical cavity surface emitting laser with a ring-shaped upper electrode structure, when the current is injected, The current will mainly concentrate on the edge area of the emission hole 100, while the current in the middle area of the emission hole 100 is small or even has no current. The current distribution in the edge area of the emission hole 100 is relatively crowded, while the central area has almost no current distribution, which will lead to vertical The overall conversion efficiency of the cavity surface emitting laser is low, and the light intensity distribution in the emission hole 100 is not uniform. In order to solve the problems found above, this embodiment provides a vertical cavity surface emitting laser, the vertical cavity surface emitting laser has an emission hole 100 and an upper electrode structure, the radial width of the emission hole 100 is not less than 15 microns, The upper electrode structure includes a peripheral electrode 101 and a plurality of grid line electrodes 102, wherein the peripheral electrode 101 is arranged on the outer periphery of the emission hole 100, and the plurality of grid line electrodes 102 are connected to the peripheral electrode 101 and extending into the emission hole 100, as shown in FIG. 1 .

The plurality of gate electrodes 102 may be connected to the peripheral electrodes 101 at intervals, and extend toward the center of the emission hole 100 . The upper electrode structure may further include several gate line connecting electrodes 103 , the gate line connecting electrodes 103 are disposed in the emission holes 100 and connected to several of the plurality of gate line electrodes 102 .

The gate line electrode 102 and the gate line connection electrode 103 can divide the emission hole 100 into a plurality of narrow and long block-shaped regions 111, and the plurality of narrow and long block-shaped regions 111 are located in the same emission hole 100, with a continuous The phases of the light rays in the narrow and long block-shaped regions 111 are basically the same, so that the vertical cavity surface emitting laser can cooperate with diffractive optical elements (DOE), so that the signal-to-noise ratio of the vertical cavity surface emitting laser can be significantly improved. Specifically, for a traditional vertical cavity surface emitting laser array (VCSEL array), the emitted light is irrelevant, and the overall light-emitting area is relatively large, and the gap between light-emitting points is also relatively large. The vertical-cavity surface-emitting laser of the present invention adopts a single large-aperture mode, and its light-emitting point emits light as a whole, which can effectively reduce the light spot, improve the signal-to-noise ratio, and maintain the coherence of the laser, which has certain advantages for optical components such as DOE. In addition, the traditional edge-emitting laser has a distinction between the fast axis and the slow axis, and its light spot is elliptical, and the divergence angles of the fast axis and the slow axis are different. The light spot is circular, and the divergence angle is the advantage of rotational symmetry.

Specifically, as shown in FIG. 1, the emission hole 100 is a circular emission hole 100, the grid line electrode 102 extends from the peripheral electrode 101 toward the center of the emission hole 100, and the grid line connection electrode 103 It is a ring-shaped grid line connection electrode 103, and the diameter of the ring-shaped grid line connection electrode 103 gradually decreases from the peripheral electrode 101 toward the center of the emission hole 100, and each of the ring-shaped grid line connections The electrodes 103 are all connected to the plurality of grid line electrodes 102 . For vertical cavity surface emitting lasers with emission holes 100 whose radial width ranges from 15 microns to 200 microns, the upper electrode structure can be as shown in Figure 1, and the number of grid electrodes 102 is preferably not less than 2, in the example shown in Figure 1, the number of the grid line electrodes 102 can be selected as 8, which are connected to the peripheral electrodes 101 at equal intervals to improve the uniformity of the current, the radial width For the vertical cavity surface emitting laser within the range, the width of the grid line electrode 102 can be set at equal width, which can not only ensure the uniformity of the current, but also reduce the manufacturing difficulty of the grid line electrode 102 and reduce the process cost. The number of the ring-shaped grid line connection electrodes 103 can be 3, etc., and each of the ring-shaped grid line connection electrodes 103 is also preferably arranged at equal intervals in the emission hole 100, and each ring-shaped grid line The gate line connection electrode 103 is connected to all the gate line electrodes 102 to reduce the resistance of the upper electrode structure and increase the current injection density. The upper electrode structure can be fabricated by using, for example, a metal lift-off process.

Certainly, in other embodiments, the shape of the emission hole 100 can also be rectangular, elliptical, etc. or other desired shapes, and the grid line electrode 102 and the grid line connecting electrode 103 can also be wavy lines , arcs, etc., or other desired line shapes are not limited to the examples listed here.

As shown in Figures 2 and 3, for a vertical cavity surface emitting laser with an emission hole 100 above 200 microns, the width of the gate electrode 102 can be set to gradually decrease from the peripheral electrode 101 toward the interior of the emission hole 100. This setting can match the current density in different regions of the emission hole 100, while ensuring the effective injection of current, and reducing the loss of the emitted laser light caused by the shielding of the grid electrode 102, as shown in FIG. 2 . In order to ensure the effective injection of current, the number of the grid line electrodes 102 can also be appropriately increased. The emission hole 100 shown in FIG. There are 32 or more grid electrodes 102 with a larger width and gradually decreasing towards the center of the emission hole 100 , and some grid electrodes 102 with equal width.

It should be noted that a large number of grid line electrodes 102 and grid line connecting electrodes 103 can more effectively improve the injection intensity and uniformity of the current, but it will cause a large area of laser shielding, resulting in weakening of the laser light intensity. A small number of grid line electrodes 102 may not be able to meet the current injection strength requirements. Therefore, in the present invention, the number of the grid line electrodes 102 is preferably between 2 and 32, and the grid line connection electrodes 103 The number is preferably between 2 and 12, and can be optimally designed according to the radial width of the emission hole 100 , and is not limited to the examples listed in FIGS. 1 to 3 .

Based on the above principles, this embodiment optimizes the width and height of the grid line electrode 102 and the grid line connection electrode 103. Since the resistance of the electrode is inversely proportional to its cross-sectional area, that is, in order to improve the resistance of the electrode, a certain degree of Increase its cross-sectional area, but electrodes with a larger cross-sectional area will cause more laser shielding. In this example, by improving the aspect ratio of the grid line electrode 102 and the grid line connection electrode 103, for example, the grid line The aspect ratio of the electrode 102 and the grid line connection electrode 103 is set between 1:1 and 6:1, which can greatly reduce the shielding of the outgoing laser light while reducing the resistance of the grid line electrode 102 and the grid line connection electrode 103 . In this embodiment, the width range of the gate line electrodes 102 and the gate line connection electrodes 103 may be between 0.1 micrometers and 2 micrometers, and the height range may be between 100 nanometers and 5 micrometers.

FIG. 5 is a schematic diagram of a cross-sectional structure at AA' in FIG. The source layer 107, the P-type conductive upper mirror 108, the dielectric layer 110 and the upper electrode structure.

The substrate 104 may be a gallium arsenide substrate 104 , and the backside of the substrate 104 has a lower electrode structure 105 .

The N-type conductive lower reflector 106 is located on the substrate 104. The N-type conductive lower reflector 106 may be an N-type conductive Bragg reflector DBR, and its main material may be gallium arsenide or the like.

The active layer 107 is located on the N-type conductive lower reflector 106. The active layer 107 is used to convert electric energy into light energy, and its material may be gallium arsenide or the like.

The P-type conductive upper mirror 108 is located on the active layer 107, the P-type conductive upper mirror 108 has a current confinement layer 109 therein, and the emission hole 100 is defined by the current confinement layer 109, The P-type conductive upper reflector 108 may be a P-type conductive Bragg reflector DBR, and its main material may be gallium arsenide or the like. The N-type conductive lower reflector 106 and the P-type conductive upper reflector 108 are used to reflect and enhance the light generated by the active layer 107, and finally form a laser beam from the surface of the P-type conductive upper reflector 108. shoot out. The current confinement layer 109 includes one of an air column current confinement structure, an ion implantation current confinement structure, a buried heterojunction current confinement structure, and an oxidation-limited current confinement structure. In this embodiment, the current confinement The confinement layer 109 is an oxidation-limited current confinement structure.

The dielectric layer 110 is located on the P-type conductive upper reflector 108 for protecting the P-type conductive upper reflector 108 .

The upper electrode structure is located on the dielectric layer 110, the peripheral electrode 101 passes through the dielectric layer 110 and forms an ohmic contact with the P-type conductive upper mirror 108, the plurality of grid electrodes 102 and The plurality of gate connecting wires pass through the dielectric layer 110 and form an ohmic contact with the P-type conductive upper mirror 108 .

The grid line electrode 102 and the grid line connection electrode 103 may include a stacked structure composed of a Ti layer, a Pt layer and an Au layer from bottom to top, and the stacked structure may be connected to the P-type conductive upper mirror 108 has good bonding strength, and after forming an ohmic contact, it has a small contact resistance. Certainly, the gate line electrodes 102 and the gate line connection electrodes 103 may also be composed of other metal stacks, and are not limited to the examples listed here.

Fig. 9 is a schematic diagram of the cross-sectional structure at BB' in Fig. 4, Fig. 9 is a schematic diagram of current injection curve, and Fig. 8 is a schematic diagram of current injection curve of a traditional vertical cavity surface emitting laser, as shown in Fig. 8 and FIG. 9, it can be seen that the current distribution in the edge region of the emission hole 100 of the traditional vertical cavity surface emitting laser is relatively crowded, while there is almost no current distribution in the central region, which will lead to a low overall conversion efficiency of the vertical cavity surface emitting laser, and the present invention The vertical cavity surface emitting laser, its current can be effectively injected into the middle region of the emission hole 100, on the one hand, it can effectively increase the current density in the middle region of the vertical cavity surface emitting laser with a large oxide aperture, on the other hand, the current can be from the said Transverse propagation by multiple grid line electrodes 102 greatly improves the uniformity of the current density distribution in the luminescent hole and improves the conversion efficiency.

This embodiment also provides a laser radar, wherein the light source of the laser radar adopts the vertical cavity surface emitting laser described in this embodiment. The traditional edge-emitting laser has a distinction between the fast axis and the slow axis, and its light spot is elliptical, and the divergence angles of the fast axis and the slow axis are different. Compared with the edge-emitting laser currently used for lidar, the present invention has a circular light spot. shape, and the divergence angle is the advantage of rotational symmetry.

This embodiment also provides an infrared camera, where the light source of the infrared camera adopts the above-mentioned vertical cavity surface emitting laser.

This embodiment also provides a 3D depth recognition detector, the light source of the depth recognition detector adopts the above-mentioned vertical cavity surface emitting laser.

Example 2

As shown in Figure 4 and Figure 6, this embodiment provides a metal grid high-power vertical cavity surface emitting laser, the basic structure of which is as in Embodiment 1, wherein the difference from Embodiment 1 is that the vertical cavity The surface-emitting laser is a vertical-cavity surface-emitting laser with a back-emitting structure, and the vertical-cavity surface-emitting laser includes: a P-type conductive lower reflector 208, and the back of the P-type conductive lower reflector 208 has a lower electrode structure 105; Layer 107, located on the P-type conductive lower reflector 208; N-type conductive upper reflector 206, located on the active layer 107, the N-type conductive upper reflector 206 has a current confinement layer 109, And the emission hole 100 is defined by the current confinement layer 109; the substrate 104 is located on the N-type conductive upper mirror 206; the dielectric layer 110 is formed on the substrate 104; and the upper electrode structure, Located on the dielectric layer 110, the peripheral electrode 101 passes through the dielectric layer 110 and forms an ohmic contact with the substrate 104, the plurality of gate electrodes 102 and the plurality of gate connection lines pass through through the dielectric layer 110 and form an ohmic contact with the substrate 104 . The grid line electrode 102 includes a stacked structure composed of Au layer, Ge layer, Ni layer and Au layer from bottom to top. Certainly, the gate electrode 102 may also be composed of other metal stacks, and is not limited to the examples listed here.

As shown in Figure 4 and Figure 7, this embodiment also provides another vertical cavity surface emitting laser, the vertical cavity surface emitting laser is a vertical cavity surface emitting laser with a back emitting structure, which includes the vertical cavity surface emitting laser It is a back-emitting structure, and the vertical cavity surface-emitting laser includes: a P-type conductive lower reflector 208, and the back of the P-type conductive lower reflector 208 has a lower electrode structure 105; an active layer 107 is located on the P-type conductive On the lower reflector 208; N-type conductive upper reflector 206, located on the active layer 107, the N-type conductive upper reflector 206 has a current confinement layer 109, and is defined by the current confinement layer 109 The emission hole 100; the substrate 104 is located on the N-type conductive upper mirror 206, and the substrate 104 located in the region of the emission hole 100 is removed to form an emission cavity to reveal the N-type conductive An upper mirror 206; a dielectric layer 110 formed on the exposed N-type conductive upper mirror 206; and an upper electrode structure, the peripheral electrode 101 of the upper electrode structure forms an ohmic contact with the substrate 104 The plurality of gate electrodes 102 and the plurality of gate connection lines of the upper electrode structure pass through the dielectric layer 110 and form an ohmic contact with the N-type conductive upper mirror 206 . The grid line electrode 102 includes a stacked structure composed of Au layer, Ge layer, Ni layer and Au layer from bottom to top. Certainly, the gate electrode 102 may also be composed of other metal stacks, and is not limited to the examples listed here.

Example 3

As shown in Figures 10 to 11, among them, Figure 11 shows a schematic cross-sectional structure at CC' in Figure 10. This embodiment provides a metal grid high-power vertical cavity surface emitting laser, and its basic structure is as shown in the implementation Example 1, wherein, the difference from Example 1 is that the plurality of gate electrodes 102 of the upper electrode are connected to the peripheral electrode 101 at intervals and arranged in parallel in the emission hole 100, The polarization structure is formed by the plurality of grid electrodes 102, and the polarization degree of the outgoing light of the vertical cavity surface emitting laser is adjusted by adjusting the distance between the plurality of grid electrodes 102, for example, the plurality of grid electrodes 102 The smaller the spacing between the wire electrodes 102, the higher the degree of polarization of the laser light finally emitted by the vertical cavity surface emitting laser, and the larger the spacing between the plurality of grid wire electrodes 102, the higher the polarization degree of the vertical cavity surface emitting laser. The lower the degree of polarization of the laser light finally emitted by the laser. Preferably, the distance between any two adjacent grid line electrodes 102 is between 4 microns and 30 microns, the width of the grid line electrodes 102 is between 0.1 micron and 2 microns, and the height is between 0.1 micron and 2 microns. Between 100 nanometers and 5 microns.

The grid wire electrode 102 of this embodiment can realize the functions of current injection and optical polarization at the same time, and can realize the optical polarization of the laser without adding additional optical elements, which can effectively reduce volume and cost.

As mentioned above, the metal grid high-power vertical cavity surface emitting laser of the present invention has the following beneficial effects:

The present invention divides the vertical cavity surface emitting laser with large oxidation aperture into a plurality of narrow and long block regions 111 by increasing the current path through multiple gate electrodes 102, on the one hand, it can effectively increase the vertical cavity surface with large oxidation aperture The current density of the middle region of the emitting laser, on the other hand, the current can be transmitted laterally from the plurality of grid electrodes 102, which greatly improves the uniformity of the current density distribution in the light-emitting hole and improves the conversion efficiency. The conversion efficiency of vertical cavity surface emitting lasers can usually reach more than 30%, or even 40-50%, depending on the degree of optimization (whether uniform injection current can be achieved while shading is minimized).

The above-mentioned multiple narrow and long block regions 111 of the present invention are located in the same emission hole 100 and are coherent, and can cooperate with diffractive optical elements (DOE), thereby significantly improving the signal-to-noise ratio of the vertical cavity surface emitting laser. At the same time, the coherence of the outgoing light is maintained in a wide range. The invention can be applied in fields such as laser radar, infrared camera and depth recognition detector.

The grid wire electrode 102 of the present invention can realize the functions of current injection and optical polarization at the same time, and realize the optical polarization of the laser without adding additional optical elements, which can effectively reduce volume and cost.

The present invention can effectively improve the power density of the vertical cavity surface emitting laser, that is, the power per unit area of the laser or laser array is improved, and the number of lasers to be used can be reduced under the same optical power requirement, and the Improve the integration level of the chip and effectively reduce the cost of the chip.

Therefore, the present invention effectively overcomes various shortcomings in the prior art and has high industrial application value.

The above-mentioned embodiments only illustrate the principles and effects of the present invention, but are not intended to limit the present invention. Anyone skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical ideas disclosed in the present invention shall still be covered by the claims of the present invention.

Claims (22)

1. a kind of high-power vertical cavity surface emitting laser of metal grill, which is characterized in that the vertical cavity surface emitting laser With launch hole and top electrode structure, the top electrode structure includes peripheral electrode and more gate line electrodes, wherein described Peripheral electrode is set to the periphery of the launch hole, and the more gate line electrodes are connected with the peripheral electrode and extend to described Within launch hole.

2. the high-power vertical cavity surface emitting laser of metal grill according to claim 1, it is characterised in that: described more Gate line electrode interval is connected in the peripheral electrode, and is extended towards the center of the launch hole.

3. the high-power vertical cavity surface emitting laser of metal grill according to claim 2, it is characterised in that: the grid line The width of electrode from the peripheral electrode towards the launch hole inside be gradually reduced.

4. the high-power vertical cavity surface emitting laser of metal grill according to claim 1,2 or 3, it is characterised in that: institute Stating top electrode structure further includes several grid line connection electrodes, and the grid line connection electrode is set in the launch hole, and institute It states and is connected with several in the more gate line electrodes.

5. the high-power vertical cavity surface emitting laser of metal grill according to claim 4, it is characterised in that: the transmitting Hole is annular emission hole, and the gate line electrode extends from the peripheral electrode towards the center of circle of the launch hole, the grid line connection Electrode is circular ring shape grid line connection electrode, and the circular ring shape grid line connection electrode is from the peripheral electrode towards the circle of the launch hole Heart orient diameter is gradually reduced, and each circular ring shape grid line connection electrode is connected with several gate line electrodes.

6. the high-power vertical cavity surface emitting laser of metal grill according to claim 1, it is characterised in that: described more Gate line electrode interval is connected in the peripheral electrode, and the parallel arrangement in the launch hole.

7. the high-power vertical cavity surface emitting laser of metal grill according to claim 6, it is characterised in that: described more Gate line electrode forms polarization structure, by adjusting the spacing between more gate line electrodes, is swashed with adjusting the vertical-cavity surface-emitting The degree of polarization of the emergent ray of light device.

8. the high-power vertical cavity surface emitting laser of metal grill according to claim 7, it is characterised in that: arbitrary neighborhood Two gate line electrodes between spacing range between 4 microns~30 microns.

9. according to claim 1, the high-power vertical cavity surface emitting laser of metal grill described in 6,7 or 8, it is characterised in that: The width range of the gate line electrode is between 0.1 micron~2 microns, and altitude range is between 100 nanometers~5 microns.

10. the high-power vertical cavity surface emitting laser of metal grill according to claim 1, it is characterised in that: the grid The quantity of line electrode is not less than 2.

11. the high-power vertical cavity surface emitting laser of metal grill according to claim 1, it is characterised in that: the hair The radial width of perforation is not less than 15 microns.

12. the high-power vertical cavity surface emitting laser of metal grill according to claim 1, it is characterised in that: described more Substrate, P-type conduction reflecting mirror or N-type in the transmitting bore region of root gate line electrode and the vertical cavity surface emitting laser is conductive Reflecting mirror forms Ohmic contact.

13. the high-power vertical cavity surface emitting laser of metal grill according to claim 12, it is characterised in that: described to hang down Straight cavity surface-emitting laser is front side emitter structure, the vertical cavity surface emitting laser further include:

The back side of substrate, the substrate has lower electrode arrangement；

Reflecting mirror under N-type conduction is located at the substrate；

Active layer is located under the N-type conduction on reflecting mirror；

P-type conduction upper reflector is located at the active layer, has current-limiting layer in the P-type conduction upper reflector, and The launch hole is defined by the current-limiting layer；And

Dielectric layer is located on the P-type conduction upper reflector；

Wherein, the more gate line electrodes pass through the dielectric layer and form Ohmic contact with the P-type conduction upper reflector.

14. the high-power vertical cavity surface emitting laser of metal grill according to claim 13, it is characterised in that: the grid Line electrode includes Ti layer from bottom to top, laminated construction composed by Pt layers and Au layers.

15. the high-power vertical cavity surface emitting laser of metal grill according to claim 12, it is characterised in that: described to hang down Straight cavity surface-emitting laser is back side emitter structure, the vertical cavity surface emitting laser further include:

Reflecting mirror under P-type conduction, the back side of reflecting mirror has lower electrode arrangement under the P-type conduction；

Active layer is located under the P-type conduction on reflecting mirror；

N-type conduction upper reflector is located at the active layer, has current-limiting layer in the N-type conduction upper reflector, and The launch hole is defined by the current-limiting layer；

Substrate is located on the N-type conduction upper reflector；And

Dielectric layer is formed on the substrate；

Wherein, the more gate line electrodes pass through the dielectric layer and form Ohmic contact with the substrate.

16. the high-power vertical cavity surface emitting laser of metal grill according to claim 15, it is characterised in that: the grid Line electrode includes Au layer from bottom to top, Ge layers, laminated construction composed by Ni layers and Au layers.

17. the high-power vertical cavity surface emitting laser of metal grill according to claim 12, it is characterised in that: described to hang down Straight cavity surface-emitting laser is back side emitter structure, the vertical cavity surface emitting laser further include:

Reflecting mirror under P-type conduction, the back side of reflecting mirror has lower electrode arrangement under the P-type conduction；

Active layer is located under the P-type conduction on reflecting mirror；

N-type conduction upper reflector is located at the active layer, has current-limiting layer in the N-type conduction upper reflector, and The launch hole is defined by the current-limiting layer；

Substrate is located on the N-type conduction upper reflector, and the substrate positioned at the transmitting bore region is removed to form hair Cavity is penetrated, to appear the N-type conduction upper reflector；And

Dielectric layer is formed on the N-type conduction upper reflector appeared；

Wherein, the more gate line electrodes pass through the dielectric layer and form Ohmic contact with the N-type conduction upper reflector.

18. the high-power vertical cavity surface emitting laser of metal grill according to claim 17, it is characterised in that: the grid Line electrode includes Au layer from bottom to top, Ge layers, laminated construction composed by Ni layers and Au layers.

19. the high-power vertical cavity surface emitting laser of metal grill described in 3~18 any one according to claim 1, special Sign is: the current-limiting layer include air column type current confinement structure, ion implantation type current confinement structure, bury it is heterogeneous One of junction type current confinement structure and oxidation limit type current confinement structure.

20. a kind of laser radar, which is characterized in that the light source of the laser radar uses such as claim 1~19 any one The high-power vertical cavity surface emitting laser of metal grill.

21. a kind of infrared camera, which is characterized in that the light source of the infrared camera is used as claim 1~19 is any The high-power vertical cavity surface emitting laser of metal grill described in one.

22. a kind of 3D depth recognition detector, which is characterized in that the light source of the depth recognition detector uses such as claim The high-power vertical cavity surface emitting laser of metal grill described in 1~19 any one.