CN110233423B - Metal grid high-power vertical cavity surface emitting laser - Google Patents
Metal grid high-power vertical cavity surface emitting laser Download PDFInfo
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- CN110233423B CN110233423B CN201910363321.0A CN201910363321A CN110233423B CN 110233423 B CN110233423 B CN 110233423B CN 201910363321 A CN201910363321 A CN 201910363321A CN 110233423 B CN110233423 B CN 110233423B
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/10—Construction or shape of the optical resonator, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region
- H01S5/18—Surface-emitting [SE] lasers, e.g. having both horizontal and vertical cavities
- H01S5/183—Surface-emitting [SE] lasers, e.g. having both horizontal and vertical cavities having only vertical cavities, e.g. vertical cavity surface-emitting lasers [VCSEL]
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/10—Construction or shape of the optical resonator, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region
- H01S5/18—Surface-emitting [SE] lasers, e.g. having both horizontal and vertical cavities
- H01S5/183—Surface-emitting [SE] lasers, e.g. having both horizontal and vertical cavities having only vertical cavities, e.g. vertical cavity surface-emitting lasers [VCSEL]
- H01S5/18308—Surface-emitting [SE] lasers, e.g. having both horizontal and vertical cavities having only vertical cavities, e.g. vertical cavity surface-emitting lasers [VCSEL] having a special structure for lateral current or light confinement
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Abstract
The invention provides a metal grid high-power vertical cavity surface emitting laser which is provided with an emitting hole and an upper electrode structure, wherein the upper electrode structure comprises a peripheral electrode and a plurality of grid line electrodes, the peripheral electrode is arranged on the periphery of the emitting hole, and the grid line electrodes are connected with the peripheral electrode and extend into the emitting hole. According to the invention, the vertical cavity surface emitting laser with the large oxidation aperture is divided into the plurality of narrow and long block-shaped areas by the plurality of grid line electrodes in a manner of increasing a current path, so that the current density of the middle area of the vertical cavity surface emitting laser with the large oxidation aperture can be effectively increased, and on the other hand, the current can be transversely transmitted from the plurality of grid line electrodes, so that the uniformity of the current density distribution in the light emitting hole is greatly improved, and the conversion efficiency is improved. Meanwhile, the coherence of emergent light is kept in a large range. The invention can be applied to the fields of laser radar, infrared cameras, depth recognition detectors and the like.
Description
Technical Field
The invention belongs to the field of semiconductor laser design and manufacture, and particularly relates to a metal grid high-power vertical cavity surface emitting laser.
Background
The Vertical Cavity Surface Emitting Laser (VCSEL) is developed on the basis of gallium arsenide semiconductor materials, is different from other light sources such as a Light Emitting Diode (LED) and a Laser Diode (LD), has the advantages of small volume, circular output light spots, single longitudinal mode output, small threshold current, low price, easiness in integration into a large-area array and the like, and is widely applied to the fields of optical communication, optical interconnection, optical storage and the like.
Vertical Cavity Surface Emitting Lasers (VCSELs) are a new type of laser that emits light vertically from the surface, and a different structure from conventional edge emitting lasers brings many advantages: the coupling efficiency of the optical fiber and the optical fiber is greatly improved by the small divergence angle and the circularly symmetric far-field and near-field distribution without a complicated and expensive beam shaping system, and the coupling efficiency of the optical fiber and the multimode optical fiber is proved to be more than 90 percent; the optical cavity is extremely short in length, so that the longitudinal mode spacing is enlarged, single longitudinal mode operation can be realized in a wider temperature range, and the dynamic modulation frequency is high; the on-chip test can be carried out, and the development cost is greatly reduced; the light-emitting direction is vertical to the substrate, the integration of a high-density two-dimensional area array can be easily realized, the higher power output is realized, and a plurality of lasers can be arranged in parallel in the direction vertical to the substrate, so the laser array is very suitable for being applied to the fields of parallel optical transmission, parallel optical interconnection and the like, the laser array is successfully applied to single-channel and parallel optical interconnection at unprecedented speed, and a great amount of application is obtained in broadband Ethernet and high-speed data communication network with high cost performance; most attractive is that its manufacturing process is compatible with Light Emitting Diodes (LEDs), which are inexpensive to manufacture on a large scale.
Vertical Cavity Surface Emitting Lasers (VCSELs) are widely used in the fields of optical communication, optical storage, optical interconnection, optical computing, solid-state lighting, laser printing, biosensing, and the like. In recent years, larger-scale application is in emerging markets of 3D face recognition, proximity sensors, laser radars, infrared camera shooting, depth detection and the like. In many practical applications, a Vertical Cavity Surface Emitting Laser (VCSEL) is required to be capable of achieving high energy density operation, and some lasers are required to maintain certain coherence of a laser light source. Making the light emitting apertures in an array can increase the light emitting power, but the energy density is limited by the spacing between the light emitting points, and coherence can also be eliminated (good for some applications, while for others it is desirable to preserve coherence). Increasing the oxide pore size is a simple and feasible solution to increase the energy density and maintain coherence. However, a Vertical Cavity Surface Emitting Laser (VCSEL) with a large oxide aperture has a problem that the current density distribution is not uniform, which results in a low conversion power and a poor uniformity of light intensity distribution.
Disclosure of Invention
In view of the above-mentioned shortcomings of the prior art, the present invention provides a metal mesh high power vcsel to solve the problems of non-uniform current density distribution of the vcsel with large oxide aperture.
In order to achieve the above and other related objects, the present invention provides a metal grid high power vcsel having an emission hole and an upper electrode structure, wherein the upper electrode structure includes a peripheral electrode and a plurality of grid line electrodes, the peripheral electrode is disposed at 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 grid line electrodes are connected to the peripheral electrode 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 inside of the emission hole.
Optionally, the upper electrode structure further includes a plurality of gate line connecting electrodes, and the gate line connecting electrodes are disposed in the emission holes and connected to a plurality of gate line electrodes.
Optionally, the emitting hole is a circular emitting hole, the gate line electrodes extend from the peripheral electrode toward the center of the emitting hole, the gate line connecting electrodes are circular ring-shaped gate line connecting electrodes, the diameters of the circular ring-shaped gate line connecting electrodes are gradually reduced from the peripheral electrode toward the center of the emitting hole, and each circular ring-shaped gate line connecting electrode is connected with the plurality of gate line electrodes.
Optionally, the plurality of gate line electrodes are connected to the peripheral electrode at intervals and arranged in parallel in the emission hole.
Optionally, the plurality of gate line electrodes form a polarization structure, and the polarization degree of the emergent light of the vertical cavity surface emitting laser is adjusted by adjusting the distance between the plurality of gate line electrodes.
Optionally, the distance between any two adjacent grid line electrodes ranges from 4 micrometers to 30 micrometers.
Optionally, the width of the gate line electrode ranges from 0.1 micron to 2 microns, and the height ranges from 100 nanometers to 5 microns.
Optionally, the number of the gate line electrodes is not less than 2.
Optionally, the radial width of the emission aperture is not less than 15 microns.
Optionally, the radial width of the emission aperture ranges between 50 microns and 1000 microns.
Optionally, the plurality of gate line electrodes form ohmic contact with the substrate, the P-type conductive mirror, or the N-type conductive mirror in the emitting hole region of the vcsel.
Optionally, the vertical cavity surface emitting laser is a front surface emitting structure, and the vertical cavity surface emitting laser further includes: the back surface of the substrate is provided with a lower electrode structure; an N-type conductive lower mirror located over the substrate; an active layer located over the N-type conductive lower mirror; a P-type conductive upper mirror located above the active layer, the P-type conductive upper mirror having a current confinement layer therein and the emission aperture being defined by the current confinement layer; and a dielectric layer located over the P-type conductive upper mirror; and the grid line electrodes penetrate through the dielectric layer and form ohmic contact with the P-type conductive upper reflector.
Optionally, the gate line electrode includes a stacked structure 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 surface emitting structure, and the vertical cavity surface emitting laser further includes: the back surface of the P-type conductive lower reflecting mirror is provided with a lower electrode structure; an active layer located over the P-type conductive lower mirror; an N-type conductive upper mirror located above the active layer, the N-type conductive upper mirror having a current confinement layer therein and the emission aperture being defined by the current confinement layer; a substrate located over the N-type conductive upper mirror; and a dielectric layer formed on the substrate; and the grid line electrodes penetrate through the dielectric layer and form ohmic contact with the substrate.
Optionally, the gate line electrode includes a stacked structure of an Au layer, a Ge layer, a Ni layer, and an Au layer from bottom to top.
Optionally, the vertical cavity surface emitting laser is a back surface emitting structure, and the vertical cavity surface emitting laser further includes: the back surface of the P-type conductive lower reflecting mirror is provided with a lower electrode structure; an active layer located over the P-type conductive lower mirror; an N-type conductive upper mirror located above the active layer, the N-type conductive upper mirror having a current confinement layer therein and the emission aperture being defined by the current confinement layer; the substrate is positioned above the N-type conductive upper reflecting mirror, and the substrate positioned in the emitting hole area is removed to form an emitting cavity so as to expose the N-type conductive upper reflecting mirror; and a dielectric layer formed on the exposed N-type conductive upper reflector; and the grid line electrodes penetrate through the dielectric layer and form ohmic contact with the N-type conductive upper reflector.
Optionally, the gate line electrode includes a stacked structure of an Au layer, a Ge layer, a Ni layer, and an Au layer from bottom to top.
Optionally, the current confinement layer includes one of an air pillar type current confinement structure, an ion implantation type current confinement structure, a buried heterojunction type current confinement structure, and an oxidation confinement type current confinement structure.
The invention also provides a laser radar, and the light source of the laser radar adopts the vertical cavity surface emitting laser.
The invention also provides an infrared camera, and the light source of the infrared camera adopts the vertical cavity surface emitting laser.
The invention also provides a 3D depth recognition detector, and the light source of the depth recognition detector adopts the vertical cavity surface emitting laser.
As described above, the metal grid high-power vertical cavity surface emitting laser of the present invention has the following beneficial effects:
according to the invention, the vertical cavity surface emitting laser with the large oxidation aperture is divided into the plurality of narrow and long block-shaped areas by the plurality of grid line electrodes in a manner of increasing a current path, so that the current density of the middle area of the vertical cavity surface emitting laser with the large oxidation aperture can be effectively increased, and on the other hand, the current can be transversely transmitted from the plurality of grid line electrodes, so that the uniformity of the current density distribution in the light emitting hole is greatly improved, and the conversion efficiency is improved. By optimizing parameters such as line width and space, the conversion efficiency of the vertical cavity surface emitting laser can reach 30-50%.
The plurality of narrow and long block-shaped regions are positioned in the same emitting hole, have coherence and can be matched with a Diffraction Optical Element (DOE), so that the signal-to-noise ratio of the vertical cavity surface emitting laser can be obviously improved. Meanwhile, the coherence of emergent light is kept in a large range. The invention can be applied to the fields of laser radar, infrared cameras, depth recognition detectors and the like.
The grid line electrode can simultaneously realize the functions of current injection, optical polarization and the like, can realize the optical polarization and the like of the laser without additionally adding optical elements, and can effectively reduce the volume and the cost. A structure of a metal grid high-power vertical cavity surface emitting laser and a manufacturing method thereof.
The invention can effectively improve the power density of the vertical cavity surface emitting laser, namely, the power of the laser or the laser array in unit area, can reduce the number of the required lasers under the same optical power requirement, can substantially improve the integration level of a chip, and effectively reduce the cost of the chip.
Drawings
Fig. 1 to 3 are schematic diagrams showing the upper electrode structure of the metal grid high-power vertical cavity surface emitting laser according to the present invention.
Fig. 4 to 5 are schematic structural diagrams of a metal mesh high-power vcsel in embodiment 1 of the present invention.
Fig. 6 is a schematic structural diagram of a metal mesh high-power vcsel in embodiment 2 of the present invention.
Fig. 7 is a schematic structural diagram of another metal grid high-power vcsel in embodiment 2 of the present invention.
Fig. 8 to 9 are schematic diagrams showing current injection distributions of the vcsel of the present invention and a conventional metal-mesh vcsel with high power, respectively.
Fig. 10 to 11 are schematic structural diagrams of a metal mesh high-power vcsel in embodiment 3 of the present invention.
Description of the element reference numerals
100 emitting hole
101 peripheral electrode
102 grid line electrode
103 gate line connecting electrode
104 substrate
105 lower electrode structure
106N type conductive lower reflector
107 active layer
108P type conductive upper reflector
109 current confinement layer
110 dielectric layer
111 narrow and long block-shaped area
206N type conductive upper reflector
208P type conductive lower reflector
Detailed Description
The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention.
Please refer to fig. 1 to 11. It should be noted that the drawings provided in the present embodiment are only for illustrating the basic idea of the present invention, and the drawings only show the components related to the present invention rather than being drawn according to the number, shape and size of the components in actual implementation, and the type, quantity and proportion of each component in actual implementation may be changed arbitrarily, and the layout of the components may be more complicated.
Example 1
As shown in fig. 1 to 5, according to research and analysis, in the conventional vertical cavity surface emitting laser with a ring-shaped upper electrode structure, when current is injected, current is mainly concentrated in the edge area of the emitting hole 100, current is smaller or even no current is present in the middle area of the emitting hole 100, current distribution in the edge area of the emitting hole 100 is crowded, and current distribution in the middle area is almost absent, which results in low overall conversion efficiency of the vertical cavity surface emitting laser and uneven light intensity distribution in the emitting hole 100. In order to solve the above-identified problems, the present embodiment provides a vertical cavity surface emitting laser, which has an emission hole 100 and an upper electrode structure, wherein a radial width of the emission hole 100 is not less than 15 μm, the upper electrode structure includes a peripheral electrode 101 and a plurality of gate line electrodes 102, the peripheral electrode 101 is disposed on an outer periphery of the emission hole 100, and the plurality of gate line electrodes 102 are connected to the peripheral electrode 101 and extend into the emission hole 100, as shown in fig. 1.
The plurality of gate line electrodes 102 may be connected to the peripheral electrode 101 at intervals, and extend toward the center of the emission hole 100. The upper electrode structure may further include a plurality of gate line connection electrodes 103, and the gate line connection electrodes 103 are disposed in the emission holes 100 and connected to a plurality of the plurality of gate line electrodes 102.
The gate line electrode 102 and the gate line connecting electrode 103 can divide the emission hole 100 into a plurality of long and narrow block-shaped regions 111, the long and narrow block-shaped regions 111 are located in the same emission hole 100 and have continuity, and the phases of light rays of the long and narrow block-shaped regions 111 are basically the same, so that the vertical cavity surface emitting laser can be matched with a Diffractive Optical Element (DOE), and the signal-to-noise ratio of the vertical cavity surface emitting laser can be remarkably improved. Specifically, in the case of a conventional vertical cavity surface emitting laser array (VCSEL array), the emitted light is incoherent, and the light emitting area as a whole is large and the gap between the light emitting points is also large. The vertical cavity surface emitting laser adopts a mode of single large aperture, the light emitting point of the vertical cavity surface emitting laser emits light integrally, light spots can be effectively reduced, the signal to noise ratio is improved, and meanwhile, the coherence of laser is kept, so that the vertical cavity surface emitting laser has certain advantages for optical components such as DOE and the like. In addition, the traditional edge-emitting laser has the advantages that the fast axis and the slow axis are distinguished, the light spot is elliptical, and the divergence angles of the fast axis and the slow axis are different.
Specifically, as shown in fig. 1, the emission hole 100 is a circular emission hole 100, the gate line electrodes 102 extend from the peripheral electrode 101 toward the center of the emission hole 100, the gate line connection electrodes 103 are circular ring-shaped gate line connection electrodes 103, the circular ring-shaped gate line connection electrodes 103 gradually decrease in diameter from the peripheral electrode 101 toward the center of the emission hole 100, and each circular ring-shaped gate line connection electrode 103 is connected to the plurality of gate line electrodes 102. For the vcsel having the radial width of the emission hole 100 in the range of 15-200 microns, the upper electrode structure may adopt the structure shown in fig. 1, and the number of the gate line electrodes 102 is preferably not less than 2, in the example shown in fig. 1, the number of the gate line electrodes 102 may be selected to be 8, and the gate line electrodes 102 are connected to the peripheral electrode 101 at equal intervals to improve the uniformity of the current, and in the vcsel having the radial width, the width of the gate line electrodes 102 may be set at equal width, which not only ensures the uniformity of the current, but also reduces the manufacturing difficulty of the gate line electrodes 102 and reduces the process cost. The number of the circular ring-shaped gate line connecting electrodes 103 may be 3, and the like, each circular ring-shaped gate line connecting electrode 103 is also preferably arranged in the emission hole 100 at an equal interval, and each circular ring-shaped gate line connecting electrode 103 is connected with all the gate line electrodes 102, so that the resistance of the upper electrode structure is reduced, and the injection density of current is improved. The upper electrode structure can be manufactured by a metal lift-off process (lift-off).
Of course, in other embodiments, the emitting hole 100 may have a rectangular shape, an oval shape, or the like, or other desired shapes, and the grid line electrode 102 and the grid line connection electrode 103 may have wavy lines, arc lines, or the like, or other desired shapes, and are not limited to the examples listed herein.
As shown in fig. 2 and 3, for the vcsel having an emission hole 100 of 200 μm or more, the width of the gate line electrode 102 may be set to gradually decrease from the peripheral electrode 101 toward the inside of the emission hole 100, and this setting may be matched with the current density in different areas of the emission hole 100, so as to reduce the loss of the emitted laser light due to the shielding of the gate line electrode 102 while ensuring the effective injection of the current, as shown in fig. 2. In order to ensure the effective injection of the current, the number of the grid line electrodes 102 may also be increased appropriately, for example, as shown in fig. 3, the emission hole 100 is a vertical cavity surface emitting laser with 400 to 1000 micrometers, the number of the grid line electrodes 102 may be 32 or more, and the grid line electrodes 102 with a larger width and gradually decreasing toward the center of the emission hole 100, and a part of the grid line electrodes 102 with the same width may be included.
It should be noted that the gate line electrodes 102 and the gate line connecting electrodes 103 with a larger number can improve the injection intensity and uniformity of the current more effectively, but can cause laser shielding of a larger area, so that the light intensity of the laser is weakened, and the gate line electrodes 102 with a smaller number may not meet the requirement of the current injection intensity, therefore, in the present invention, the number of the gate line electrodes 102 is preferably between 2 to 32, the number of the gate line connecting electrodes 103 is preferably between 2 to 12, the optimal design can be performed according to the radial width of the emitting holes 100, and the present invention is not limited to the examples illustrated in fig. 1 to 3.
Based on the above principle, the width and height of the gate line electrode 102 and the gate line connecting electrode 103 are optimized in this embodiment, since the resistance of the electrode is in inverse proportion to the cross-sectional area thereof, that is, the cross-sectional area of the electrode needs to be increased to a certain extent in order to improve the resistance of the electrode, but the electrode with a larger cross-sectional area may cause more laser shielding, in this example, the shielding of the outgoing laser is greatly reduced while the resistance of the gate line electrode 102 and the gate line connecting electrode 103 is reduced by increasing the aspect ratio of the gate line electrode 102 and the gate line connecting electrode 103, for example, setting the aspect ratio of the gate line electrode 102 and the gate line connecting electrode 103 to be 1: 1-6: 1. In this embodiment, the gate line electrode 102 and the gate line connection electrode 103 may have a width ranging from 0.1 to 2 micrometers and a height ranging from 100 to 5 micrometers.
Fig. 5 is a schematic cross-sectional view taken along line a-a' of fig. 4, where the vcsel has a front emission structure and the vcsel includes a substrate 104, an N-type conductive lower mirror 106, an active layer 107, a P-type conductive upper mirror 108, a dielectric layer 110, and an upper electrode structure.
The substrate 104 may be a gallium arsenide substrate 104, and the back surface of the substrate 104 has a lower electrode structure 105.
The N-type conductive lower mirror 106 is located on the substrate 104, and the N-type conductive lower mirror 106 may be an N-type conductive bragg reflector DBR, the main material of which may be gallium arsenide, or the like.
The active layer 107 is located on the N-type conductive lower mirror 106, and the active layer 107 is used to convert electrical energy into optical energy, and may be made of 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, and the P-type conductive upper mirror 108 may be a P-type conductive bragg mirror DBR, and a main material thereof may be gallium arsenide or the like. The N-type conductive lower mirror 106 and the P-type conductive upper mirror 108 are used for enhancing the reflection of the light generated by the active layer 107, and finally forming laser light to be emitted from the surface of the P-type conductive upper mirror 108. The current confinement layer 109 includes one of an air pillar type current confinement structure, an ion implantation type current confinement structure, a buried heterojunction type current confinement structure, and an oxidation confinement type current confinement structure, and in this embodiment, the current confinement layer 109 is an oxidation confinement type current confinement structure.
The dielectric layer 110 is located above the P-type conductive upper mirror 108 and is used for protecting the P-type conductive upper mirror 108.
The upper electrode structure is located on the dielectric layer 110, the peripheral electrode 101 penetrates through the dielectric layer 110 and forms ohmic contact with the P-type conductive upper reflector 108, and the plurality of gate line electrodes 102 and the plurality of gate connection lines penetrate through the dielectric layer 110 and form ohmic contact with the P-type conductive upper reflector 108.
The gate line electrode 102 and the gate line connection electrode 103 may include a stacked structure of a Ti layer, a Pt layer, and an Au layer from bottom to top, and the stacked structure may have a better bonding strength with the P-type conductive upper mirror 108 and a smaller contact resistance after ohmic contact is formed. Of course, the gate line electrode 102 and the gate line connection electrode 103 may be formed of other metal stacked layers, and are not limited to the examples listed herein.
Fig. 9 is a schematic cross-sectional structure diagram at B-B' in fig. 4, where the clip in fig. 9 is an injection schematic curve of current, and the clip in fig. 8 is an injection schematic curve of current of the conventional vcsel, and as can be seen from fig. 8 and 9, the current distribution in the edge region of the conventional vcsel aperture 100 is crowded, and the current distribution in the middle region is almost zero, which results in low overall conversion efficiency of the vcsel, whereas the current of the vcsel laser can be effectively injected into the middle region of the emission aperture 100, on one hand, the current density in the middle region of the vcsel aperture with large oxide aperture can be effectively increased, and on the other hand, the current can be laterally propagated from the plurality of grid electrodes 102, which greatly improves the uniformity of the current density distribution in the emission aperture, the conversion efficiency is improved.
The present embodiment further provides a lidar, wherein a light source of the lidar employs the vertical cavity surface emitting laser according to the present embodiment. Compared with the prior edge-emitting laser used for the laser radar, the edge-emitting laser has the advantages that the light spots are circular, and the divergence angles are rotationally symmetrical.
The embodiment further provides an infrared camera, and the light source of the infrared camera adopts the vertical cavity surface emitting laser.
The embodiment further provides a 3D depth recognition detector, and the light source of the depth recognition detector adopts the vertical cavity surface emitting laser.
Example 2
As shown in fig. 4 and fig. 6, the present embodiment provides a metal mesh high-power vcsel, whose basic structure is as in embodiment 1, wherein the difference from embodiment 1 is that the vcsel is a vcsel with a backside emitting structure, and the vcsel includes: a P-type conductive lower mirror 208, a back surface of the P-type conductive lower mirror 208 having a lower electrode structure 105; an active layer 107 located above the P-type conductive lower mirror 208; an N-type conductive upper mirror 206 located above the active layer 107, the N-type conductive upper mirror 206 having a current confinement layer 109 therein, the current confinement layer 109 defining the emission hole 100; a substrate 104 located above the N-type conductive upper mirror 206; a dielectric layer 110 formed on the substrate 104; and an upper electrode structure located on the dielectric layer 110, wherein the peripheral electrode 101 penetrates through the dielectric layer 110 and forms ohmic contact with the substrate 104, and the plurality of gate line electrodes 102 and the plurality of gate connection lines penetrate through the dielectric layer 110 and form ohmic contact with the substrate 104. The gate line electrode 102 includes a stacked structure of an Au layer, a Ge layer, a Ni layer, and an Au layer from bottom to top. Of course, the gate line electrode 102 may be formed of other metal stacked layers, and is not limited to the examples listed herein.
As shown in fig. 4 and fig. 7, this embodiment further provides another vertical cavity surface emitting laser, where the vertical cavity surface emitting laser is a vertical cavity surface emitting laser with a back surface emitting structure, and the vertical cavity surface emitting laser includes: a P-type conductive lower mirror 208, a back surface of the P-type conductive lower mirror 208 having a lower electrode structure 105; an active layer 107 located above the P-type conductive lower mirror 208; an N-type conductive upper mirror 206 located above the active layer 107, the N-type conductive upper mirror 206 having a current confinement layer 109 therein, the current confinement layer 109 defining the emission hole 100; a substrate 104 located on the N-type conductive upper mirror 206, wherein the substrate 104 located in the area of the emission hole 100 is removed to form an emission cavity so as to expose the N-type conductive upper mirror 206; a dielectric layer 110 formed on the exposed N-type conductive upper mirror 206; and an upper electrode structure, wherein the peripheral electrode 101 of the upper electrode structure forms an ohmic contact with the substrate 104, and the plurality of gate line electrodes 102 and the plurality of gate connection lines of the upper electrode structure penetrate through the dielectric layer 110 and form an ohmic contact with the N-type conductive upper mirror 206. The gate line electrode 102 includes a stacked structure of an Au layer, a Ge layer, a Ni layer, and an Au layer from bottom to top. Of course, the gate line electrode 102 may be formed of other metal stacked layers, and is not limited to the examples listed herein.
Example 3
As shown in fig. 10 to 11, wherein fig. 11 is a schematic cross-sectional view at C-C' of fig. 10, the present embodiment provides a metal mesh high-power vcsel, the basic structure is as in embodiment 1, wherein, different from embodiment 1, the plurality of gate line electrodes 102 of the upper electrode are connected to the peripheral electrode 101 at intervals, and arranged in parallel in the emission hole 100, forming a polarization structure by the plurality of gate line electrodes 102, the degree of polarization of the light emitted from the vcsel is adjusted by adjusting the spacing between the gate line electrodes 102, for example, the smaller the spacing between the gate line electrodes 102, the higher the polarization degree of the laser light finally emitted by the vertical cavity surface emitting laser is, the larger the distance between the plurality of gate line electrodes 102 is, the lower the polarization degree of the laser light finally emitted by the vertical cavity surface emitting laser is. Preferably, the distance between any two adjacent grid line electrodes 102 ranges from 4 micrometers to 30 micrometers, the width of the grid line electrode 102 ranges from 0.1 micrometer to 2 micrometers, and the height ranges from 100 nanometers to 5 micrometers.
The gate line electrode 102 of the present embodiment can simultaneously realize the current injection function and the optical polarization function, and the optical polarization function of the laser can be realized without additionally adding an optical element, so that the volume and the cost can be effectively reduced.
As described above, the metal grid high-power vertical cavity surface emitting laser of the present invention has the following beneficial effects:
according to the invention, the vertical cavity surface emitting laser with the large oxidation aperture is divided into the plurality of narrow and long block-shaped regions 111 by the plurality of grid line electrodes 102 in a manner of increasing a current path, so that on one hand, the current density of the middle region of the vertical cavity surface emitting laser with the large oxidation aperture can be effectively increased, on the other hand, the current can be transversely transmitted from the plurality of grid line electrodes 102, the uniformity of the current density distribution in the light emitting hole is greatly improved, and the conversion efficiency is improved.
The plurality of narrow and long block-shaped regions 111 are located in the same emission hole 100, have coherence, and can be matched with a Diffractive Optical Element (DOE), so that the signal-to-noise ratio of the vertical cavity surface emitting laser can be remarkably improved. Meanwhile, the coherence of emergent light is kept in a large range. The invention can be applied to the fields of laser radar, infrared cameras, depth recognition detectors and the like.
The grid line electrode 102 of the invention can simultaneously realize the functions of current injection, optical polarization and the like, can realize the optical polarization and the like of the laser without additionally adding optical elements, and can effectively reduce the volume and the cost.
The invention can effectively improve the power density of the vertical cavity surface emitting laser, namely, the power of the laser or the laser array in unit area, can reduce the number of the required lasers under the same optical power requirement, can substantially improve the integration level of a chip, and effectively reduce the cost of the chip.
Therefore, the invention effectively overcomes various defects in the prior art and has high industrial utilization value.
The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.
Claims (15)
1. A metal grid high-power vertical cavity surface emitting laser is characterized in that the vertical cavity surface emitting laser is provided with an emitting hole and an upper electrode structure, the upper electrode structure comprises a peripheral electrode and a plurality of grid line electrodes, the peripheral electrode is arranged on the periphery of the emitting hole, the grid line electrodes are connected with the peripheral electrode and extend into the emitting hole, a dielectric layer is arranged on the surface of a substrate, a P-type conductive reflector or an N-type conductive reflector in the emitting hole area of the vertical cavity surface emitting laser, the grid line electrodes penetrate through the dielectric layer to form ohmic contact with the substrate, the P-type conductive reflector or the N-type conductive reflector in the emitting hole area of the vertical cavity surface emitting laser, the height-to-width ratio of the grid line electrodes is 1: 1-6: 1, and the radial width of the emitting hole is not less than 15 microns, the grid line electrodes are connected to the peripheral electrode at intervals and extend towards the center of the emission hole, and the width of the grid line electrodes is gradually reduced from the peripheral electrode towards the inside of the emission hole.
2. The metal mesh high power vertical cavity surface emitting laser of claim 1, wherein: the upper electrode structure further comprises a plurality of grid line connecting electrodes, and the grid line connecting electrodes are arranged in the emission holes and connected with a plurality of grid line electrodes.
3. The metal mesh high power vertical cavity surface emitting laser of claim 2, wherein: the emitting hole is a circular emitting hole, the grid line electrode extends from the peripheral electrode to the center of the emitting hole, the grid line connecting electrode is a circular ring-shaped grid line connecting electrode, and the diameter of the circular ring-shaped grid line connecting electrode is gradually reduced from the peripheral electrode to the center of the emitting hole.
4. The metal mesh high power vertical cavity surface emitting laser of claim 1, wherein: the width range of the grid line electrode is between 0.1 and 2 microns, and the height range of the grid line electrode is between 100 and 5 microns.
5. The metal mesh high power vertical cavity surface emitting laser of claim 1, wherein: the number of the grid line electrodes is not less than 2.
6. The metal mesh high power vertical cavity surface emitting laser of claim 1, wherein: the vertical cavity surface emitting laser is a front surface emitting structure, and further includes:
the back surface of the substrate is provided with a lower electrode structure;
an N-type conductive lower mirror located over the substrate;
an active layer located over the N-type conductive lower mirror;
a P-type conductive upper mirror located above the active layer, the P-type conductive upper mirror having a current confinement layer therein and the emission aperture being defined by the current confinement layer; and
a dielectric layer located over the P-type conductive upper mirror;
and the grid line electrodes penetrate through the dielectric layer and form ohmic contact with the P-type conductive upper reflector.
7. The metal mesh high power VCSEL of claim 6, wherein: the grid line electrode comprises a laminated structure consisting of a Ti layer, a Pt layer and an Au layer from bottom to top.
8. The metal mesh high power vertical cavity surface emitting laser of claim 1, wherein: the vertical cavity surface emitting laser is a back surface emitting structure, and further includes:
the back surface of the P-type conductive lower reflecting mirror is provided with a lower electrode structure;
an active layer located above the P-type conductive lower mirror, the P-type conductive lower mirror having a current confinement layer therein, the current confinement layer defining the emission hole;
an N-type conductive upper mirror located over the active layer;
a substrate located over the N-type conductive upper mirror; and
a dielectric layer formed on the substrate;
and the grid line electrodes penetrate through the dielectric layer and form ohmic contact with the substrate.
9. The metal mesh high power vertical cavity surface emitting laser of claim 8, wherein: the grid line electrode comprises a laminated structure consisting of an Au layer, a Ge layer, a Ni layer and an Au layer from bottom to top.
10. The metal mesh high power vertical cavity surface emitting laser of claim 1, wherein: the vertical cavity surface emitting laser is a back surface emitting structure, and further includes:
the back surface of the P-type conductive lower reflecting mirror is provided with a lower electrode structure;
an active layer located above the P-type conductive lower mirror, the P-type conductive lower mirror having a current confinement layer therein, the current confinement layer defining the emission hole;
an N-type conductive upper mirror located over the active layer;
the substrate is positioned above the N-type conductive upper reflecting mirror, and the substrate positioned in the emitting hole area is removed to form an emitting cavity so as to expose the N-type conductive upper reflecting mirror; and
the dielectric layer is formed on the exposed N-type conductive upper reflecting mirror;
and the grid line electrodes penetrate through the dielectric layer and form ohmic contact with the N-type conductive upper reflector.
11. The metal mesh high power vertical cavity surface emitting laser of claim 10, wherein: the grid line electrode comprises a laminated structure consisting of an Au layer, a Ge layer, a Ni layer and an Au layer from bottom to top.
12. The metal grid high-power vertical cavity surface emitting laser according to any one of claims 6 to 11, wherein: the current confinement layer includes one of an air column type current confinement structure, an ion injection type current confinement structure, a buried heterojunction type current confinement structure, and an oxidation confinement type current confinement structure.
13. A lidar characterized in that a metal grid high-power vertical cavity surface emitting laser according to any one of claims 1 to 12 is adopted as a light source of the lidar.
14. An infrared camera is characterized in that a light source of the infrared camera adopts the metal grid high-power vertical cavity surface emitting laser as claimed in any one of claims 1 to 12.
15. A3D depth recognition detector, characterized in that the light source of the depth recognition detector adopts the metal grid high-power vertical cavity surface emitting laser as claimed in any one of claims 1 to 12.
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| CN201910000402.4A CN109326958A (en) | 2019-01-02 | 2019-01-02 | The high-power vertical cavity surface emitting laser of metal grill |
| CN2019100004024 | 2019-01-02 |
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| CN201910363321.0A Active CN110233423B (en) | 2019-01-02 | 2019-04-30 | Metal grid high-power vertical cavity surface emitting laser |
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| CN111081831B (en) * | 2019-11-20 | 2021-03-23 | 华南师范大学 | Multi-electrode-based illumination communication device and preparation method thereof |
| CN112186503B (en) * | 2020-10-21 | 2021-11-02 | 中国科学院长春光学精密机械与物理研究所 | Vertical cavity surface emitting laser and manufacturing method thereof |
| GB2622230A (en) * | 2022-09-06 | 2024-03-13 | Vector Photonics Ltd | Electrical contact |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0692827A1 (en) * | 1994-07-11 | 1996-01-17 | Sony Corporation | Surface-emitting semiconductor light emitting device |
| EP1028505A1 (en) * | 1999-02-11 | 2000-08-16 | CSEM Centre Suisse d'Electronique et de Microtechnique S.A. - Recherche et Développement | A vertical-cavity surface-emitting laser comprised of single laser elements arranged on a common substrate |
| CN1889314A (en) * | 2006-08-02 | 2007-01-03 | 长春理工大学 | Multi-core electric filling structure for large out light hole vertical cavity surface emitting semiconductor laser |
| CN101521353A (en) * | 2009-04-08 | 2009-09-02 | 中国科学院长春光学精密机械与物理研究所 | Vertical cavity surface emitting laser (VCSEL) capable of controlling polarization through emergent light window electrode structure |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1133217C (en) * | 2000-08-15 | 2003-12-31 | 中国科学院半导体研究所 | Surficial luminous semiconductor device and method for increasing transverse current |
| KR100427583B1 (en) * | 2002-01-16 | 2004-04-28 | 한국전자통신연구원 | Method for fabricating long wavelength vertical-cavity surface emitting lasers |
| JP4062983B2 (en) * | 2002-06-20 | 2008-03-19 | 富士ゼロックス株式会社 | Surface emitting semiconductor laser and manufacturing method thereof |
| CN103178443B (en) * | 2013-03-01 | 2014-10-15 | 中国科学院长春光学精密机械与物理研究所 | Vertical-cavity surface-emitting laser capable of automatically focusing |
| US9762027B2 (en) * | 2014-04-30 | 2017-09-12 | Finisar Corporation | Beam steering modulated VCSEL |
| JP6651144B2 (en) * | 2014-08-29 | 2020-02-19 | 国立大学法人京都大学 | Two-dimensional photonic crystal surface emitting laser |
-
2019
- 2019-01-02 CN CN201910000402.4A patent/CN109326958A/en not_active Withdrawn
- 2019-04-30 CN CN201910363321.0A patent/CN110233423B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0692827A1 (en) * | 1994-07-11 | 1996-01-17 | Sony Corporation | Surface-emitting semiconductor light emitting device |
| EP1028505A1 (en) * | 1999-02-11 | 2000-08-16 | CSEM Centre Suisse d'Electronique et de Microtechnique S.A. - Recherche et Développement | A vertical-cavity surface-emitting laser comprised of single laser elements arranged on a common substrate |
| CN1889314A (en) * | 2006-08-02 | 2007-01-03 | 长春理工大学 | Multi-core electric filling structure for large out light hole vertical cavity surface emitting semiconductor laser |
| CN101521353A (en) * | 2009-04-08 | 2009-09-02 | 中国科学院长春光学精密机械与物理研究所 | Vertical cavity surface emitting laser (VCSEL) capable of controlling polarization through emergent light window electrode structure |
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| CN109326958A (en) | 2019-02-12 |
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