阅读说明：本技术 一种高阶模选择抑制型垂直面发射激光器及其制备方法 (High-order mode selection suppression type vertical surface emitting laser and preparation method thereof ) 是由 王岩 罗帅 季海铭 于 2019-11-25 设计创作，主要内容包括：本发明涉及光子光电子器件设计、制作领域,尤其涉及一种高阶模选择抑制型垂直面发射激光器及其制备方法,其特征在于,高阶模选择抑制型垂直面发射激光器包括由下至上依次设置的N电极层、衬底、下布拉格反射层和发光单元圆台,发光单元圆台随机均匀分布于下布拉格反射层上构成随机单元阵列,相邻两发光单元圆台之间设有间隙；发光单元圆台包括由下至上依次设置的有源区、氧化限制层、上布拉格反射层、接触层、透明介质层,透明介质层具有不同刻蚀图案形成了高阶模选择抑制结构,高阶模选择抑制结构刻蚀图案的刻蚀深度满足四分之一波长相位相消条件。本发明实现高阶模抑制,保证光输出效率不受影响,稳定性强。(The invention relates to the field of design and manufacture of photonic optoelectronic devices, in particular to a high-order mode selection suppression type vertical surface emitting laser and a preparation method thereof, which are characterized in that the high-order mode selection suppression type vertical surface emitting laser comprises an N electrode layer, a substrate, a lower Bragg reflection layer and a light emitting unit circular table which are sequentially arranged from bottom to top, the light emitting unit circular table is uniformly distributed on the lower Bragg reflection layer at random to form a random unit array, and a gap is arranged between two adjacent light emitting unit circular tables; the light-emitting unit round platform comprises an active region, an oxidation limiting layer, an upper Bragg reflecting layer, a contact layer and a transparent medium layer which are sequentially arranged from bottom to top, wherein the transparent medium layer is provided with different etching patterns to form a high-order mode selection inhibiting structure, and the etching depth of the etching patterns of the high-order mode selection inhibiting structure meets the quarter-wavelength phase cancellation condition. The invention realizes high-order mode suppression, ensures that the light output efficiency is not influenced and has strong stability.)

1. A high-order mode selection suppression type vertical surface emitting laser is characterized in that: comprises that

An N electrode layer;

the substrate is arranged on the N electrode layer;

a lower Bragg reflection layer arranged on the substrate;

the light-emitting unit round tables are randomly and uniformly distributed on the lower Bragg reflecting layer to form a random unit array, and a gap is formed between every two adjacent light-emitting unit round tables; wherein, the luminescence unit round platform includes:

the active region is arranged on the lower Bragg reflection layer;

the oxidation limiting layer is arranged on the lower Bragg reflecting layer, and the center of the oxidation limiting layer is provided with an oxidation aperture;

an upper Bragg reflection layer arranged on the oxidation limiting layer;

a contact layer disposed on the upper Bragg reflection layer;

the P electrode layer is arranged on the contact layer;

the transparent medium layer is arranged on the contact layer; the transparent medium layer is provided with different etching patterns to form a high-order mode selection inhibiting structure, and the etching depth of the etching patterns of the high-order mode selection inhibiting structure meets the quarter-wavelength phase cancellation condition.

2. The higher-order mode selection suppression type vertical plane emission laser according to claim 1, characterized in that: the etching pattern of the high-order mode selection suppression structure comprises a circular ring pattern, four crescent moon patterns and a wedge-shaped pattern arranged in a ring shape; a circular ring pattern is adopted for inhibiting the high-order modes LP13 and LP12, four crescent patterns are adopted for inhibiting the LP11 mode, and a ring-shaped wedge pattern is adopted for inhibiting the high-order modes except the fundamental mode LP 01.

3. The higher-order mode selection suppression type vertical plane emission laser according to claim 1, characterized in that: the P electrode layer wraps the circular table of the light-emitting unit and the outer area, an opening of the P electrode layer positioned in the middle of the upper part of the circular table of the light-emitting unit forms an upper electrode window, and the transparent medium layer is arranged at the upper electrode window; the P electrode layer at the outer edge of the upper electrode window is contacted with the contact layer; an insulating layer is arranged between the light-emitting unit round platform and the outer region and the P electrode layer.

4. The higher-order mode selection suppression type vertical plane emission laser according to claim 1, characterized in that: the lower Bragg reflection layer comprises 30-50 pairs of Al0.1GaAs/Al0.9GaAs reflection layers, the optical thickness of each reflection layer is one-fourth laser lasing wavelength, and two sub-layers of each pair of reflection layers have component gradual change characteristics; the DBR is lightly doped at two pairs adjacent to the active region, and has an N-doping concentration no greater than 5 x 10^17/cm³The doping concentration range of other lower DBRs is 5 x 10^17/cm³～5×10^18/cm³(ii) a The upper Bragg reflection layer comprises 10-30 pairs of Al0.1GaAs/Al0.9GaAs reflection layers, the optical thickness of each layer is one-fourth laser lasing wavelength, and two sub-layers of each pair of reflection layers have component gradual change characteristics; the DBR is lightly doped in two pairs adjacent to the active region, and has a P doping concentration no greater than 5 x 10^17/cm³The doping concentration range of other upper DBRs is 5 x 10^17/cm³～5×10^18/cm³。

5. The higher-order mode selection suppression type vertical plane emission laser according to claim 1, characterized in that: the active region is an InGaAs/GaAs, InGaAs/AlGaAs, InGaAs/GaAsP multi-quantum well structure, and the central wavelength of an emission spectrum is matched with the lasing wavelength of a laser; matching layers are arranged on the upper side and the lower side of the multiple quantum well and used for adjusting the cavity mode wavelength.

6. The higher-order mode selection suppression type vertical plane emission laser according to claim 1, characterized in that: the oxidation limiting layer is a high-aluminum component layer, is made of AlGaAs and forms Al under the condition of high-temperature wet oxygen₂O₃An insulating layer to confine current and an optical field; the contact layer is a P-type highly doped GaAs material with the thickness of 5-50 nm and the doping concentration of 1 x 10^19/cm³～5×10^19/cm³。

7. A preparation method of a high-order mode selection inhibition type vertical surface emitting laser is characterized by comprising the following steps:

step 1): preparing a photoetching plate for photoetching the circular table of the light-emitting unit;

step 2): a photoetching plate is utilized to photoetch the circular truncated cone of the light-emitting unit on the conventional vertical cavity surface emission epitaxial material, and the outer area of the circular truncated cone is etched to be below the active area of the epitaxial material;

step 3): oxidizing the high-alumina component layer by using high-temperature wet oxygen to form an oxidized aperture, and limiting a current and an optical field;

step 4): growing an insulating layer and corroding an upper electrode window;

step 5): photoetching and metal stripping to form a P electrode layer;

step 6): covering a transparent medium layer;

step 7): photoetching and etching the high-order mode selection inhibition structure etching pattern of each light-emitting unit circular truncated cone;

step 8): thinning the wafer;

step 9): evaporating the N electrode layer and annealing.

8. The method for manufacturing a higher-order mode selection suppression type vertical surface emitting laser according to claim 7, characterized in that: the step 1) is specifically as follows:

step 1.1): setting the radius of the circular truncated cone of the light-emitting unit as R1, firstly, carrying out close packing arrangement on a circle with the radius of R1+ R2 in an array region to obtain the center coordinates { xi, yi } and the total number N of the circle with the radius of R1+ R2, wherein R2 is a positive number;

step 1.2): generating 4 multiplied by N random numbers in a range of-0.5 by using a uniformly distributed random number generation method, wherein each 4 random numbers are used as a group for determining the direction and offset of coordinates { xi, yi } of each circle with the radius of R1, and the change amplitude of the coordinates is less than 0.5 times of R2;

step 1.3): screening and removing coordinates of which the variation amplitude of the unqualified coordinates is less than 0.5 time of R2, and regenerating the unqualified coordinates;

step 1.4): and (4) taking the finally obtained coordinates as a circle center and R1 as a radius to manufacture the photoetching plate.

9. The method for manufacturing a higher-order mode selection suppression type vertical surface emitting laser according to claim 7, characterized in that: the conventional vertical cavity surface emitting epitaxial material comprises a substrate, a lower Bragg reflection layer, an active region, an oxidation limiting layer, an upper Bragg reflection layer and a contact layer which are sequentially stacked from bottom to top.

10. The method for manufacturing a higher-order mode selection suppression type vertical surface emitting laser according to claim 7, characterized in that: the step 7) is specifically as follows: etching the depth of the high-order mode selective inhibition structure pattern to meet the quarter-wavelength phase cancellation condition; a circular ring pattern is adopted for inhibiting the high-order modes LP13 and LP12, a 4-month tooth pattern is adopted for inhibiting the LP11 mode, and a ring-shaped wedge pattern is adopted for inhibiting the high-order modes except the fundamental mode LP 01.

Technical Field

The invention relates to the field of design and manufacture of photonic optoelectronic devices, in particular to a high-order mode selection suppression type vertical surface emitting laser and a preparation method thereof.

Background

The structured light method is an active optical measurement technology, and the basic principle is that a structured light projector projects controllable light spots, light bars or smooth surface structures to the surface of a measured object, an image sensor (such as a camera) obtains images, and the three-dimensional coordinates of the object are calculated by utilizing the trigonometric principle through the system geometric relationship. The structured light measurement method has the characteristics of simple calculation, small volume, low price and convenience in installation and maintenance, and is widely used in actual three-dimensional profile measurement. When the optical surface structured light is adopted, the two-dimensional structured light pattern is projected onto the surface of an object, so that three-dimensional profile measurement can be realized without scanning, the measurement speed is high, the random coding structured light has high matching precision and robustness, and is projected onto the surface of the measured object, so that the surface of the object has abundant texture information, the three-dimensional matching is not influenced by the surface texture of the object, the random coding structured light has strong external noise resistance, and the requirement of field measurement is met.

At present, the randomly distributed structured light is generally generated by irradiating laser beams on random diffraction optical elements such as gratings, the structured light has high requirements on the light emitting mode and the shape of light spots of each unit, the shapes of the light spots comprise a Gaussian type, a rabbit ear type, a super Gaussian type and the like, the lasing mode of each light emitting unit needs to be accurately controlled, and the currently issued products are mainly controlled by means of oxidizing aperture; the invention provides a high-order mode selection inhibition type vertical surface emitting laser and a preparation method thereof, which are used for generating structured light applied to three-dimensional modeling three-dimensional face or other object recognition.

Disclosure of Invention

The invention aims to provide a high-order mode selective suppression type vertical surface emitting laser and a preparation method thereof, which can realize high-order mode suppression, ensure that the light output efficiency is not influenced and have strong stability.

In order to solve the technical problems, the technical scheme of the invention is as follows: a high-order mode selection suppression type vertical surface emitting laser comprises an N electrode layer;

the substrate is arranged on the N electrode layer;

a lower Bragg reflection layer arranged on the substrate;

the light-emitting unit round tables are randomly and uniformly distributed on the lower Bragg reflecting layer to form a random unit array, and a gap is formed between every two adjacent light-emitting unit round tables; wherein, the luminescence unit round platform includes:

the active region is arranged on the lower Bragg reflection layer;

the oxidation limiting layer is arranged on the lower Bragg reflecting layer, and the center of the oxidation limiting layer is provided with an oxidation aperture;

an upper Bragg reflection layer arranged on the oxidation limiting layer;

a contact layer disposed on the upper Bragg reflection layer;

the P electrode layer is arranged on the contact layer;

the transparent medium layer is arranged on the contact layer; the transparent medium layer is provided with different etching patterns to form a high-order mode selection inhibiting structure, and the etching depth of the etching patterns of the high-order mode selection inhibiting structure meets the quarter-wavelength phase cancellation condition.

According to the scheme, the etching pattern of the high-order mode selection suppression structure comprises a circular ring pattern, four crescent patterns and a ring-shaped arrangement wedge pattern; a ring pattern is adopted for inhibiting the high-order modes LP13 and LP12, four crescent patterns are adopted for inhibiting the LP11 mode, and a ring-shaped wedge pattern is adopted for inhibiting the high-order modes except the fundamental mode LP 01; the combined application of several patterns achieves selective suppression of the pattern.

According to the scheme, the P electrode layer wraps the circular table of the light-emitting unit and the outer area, an opening of the P electrode layer positioned in the middle of the upper portion of the circular table of the light-emitting unit forms an upper electrode window, and the transparent medium layer is arranged at the upper electrode window; the P electrode layer at the outer edge of the upper electrode window is contacted with the contact layer; an insulating layer is arranged between the light-emitting unit round platform and the outer region and the P electrode layer.

According to the scheme, the lower Bragg reflection layer comprises 30-50 pairs of Al0.1GaAs/Al0.9GaAs reflection layers, the optical thickness of each layer is one-fourth laser lasing wavelength, and two sub-layers of each pair of reflection layers have component gradual change characteristics; the DBR is lightly doped at two pairs adjacent to the active region, and has an N-doping concentration no greater than 5 x 10^17/cm³The doping concentration range of other lower DBRs is 5 x 10^17/cm³～5×10^18/cm³(ii) a The upper Bragg reflection layer comprises 10-30 pairs of Al0.1GaAs/Al0.9GaAs reflection layers, the optical thickness of each layer is one-fourth laser lasing wavelength, and two sub-layers of each pair of reflection layers have component gradual change characteristics; the DBR is lightly doped in two pairs adjacent to the active region, and has a P doping concentration no greater than 5 x 10^17/cm³The doping concentration range of other upper DBRs is 5 x 10^17/cm³～5×10^18/cm³。

According to the scheme, the active region is an InGaAs/GaAs, InGaAs/AlGaAs, InGaAs/GaAsP multi-quantum well structure, and the central wavelength of an emission spectrum is matched with the lasing wavelength of a laser; matching layers are arranged on the upper side and the lower side of the multiple quantum well and used for adjusting the cavity mode wavelength.

According to the scheme, the oxidation limiting layer is a high-aluminum component layer, the material is AlGaAs, and Al is formed under the condition of high-temperature wet oxygen₂O₃An insulating layer to confine the current and the optical field.

According to the scheme, the contact layer is a p-type highly doped GaAs material, the thickness is 5 nm-50 nm, and the doping concentration is 1 multiplied by 10^19/cm³～5×10^19/cm³。

A preparation method of a high-order mode selection inhibition type vertical surface emitting laser is characterized by comprising the following steps:

step 1): preparing a photoetching plate for photoetching the circular table of the light-emitting unit;

step 2): a photoetching plate is utilized to photoetch the circular truncated cone of the light-emitting unit on the conventional vertical cavity surface emission epitaxial material, and the outer area of the circular truncated cone is etched to be below the active area of the epitaxial material;

step 3): oxidizing the high-alumina component layer by using high-temperature wet oxygen to form an oxidized aperture, and limiting a current and an optical field;

step 4): growing an insulating layer and corroding an upper electrode window;

step 5): photoetching and metal stripping to form a P electrode layer;

step 6): covering a transparent medium layer;

step 7): photoetching and etching the high-order mode selection inhibition structure etching pattern of each light-emitting unit circular truncated cone;

step 8): thinning the wafer;

step 9): evaporating the N electrode layer and annealing.

According to the scheme, the step 1) is specifically as follows:

step 1.1): setting the radius of the circular truncated cone of the light-emitting unit as R1, firstly, carrying out close packing arrangement on a circle with the radius of R1+ R2 in an array region to obtain the center coordinates { xi, yi } and the total number N of the circle with the radius of R1+ R2, wherein R2 is a positive number; step 1.2): generating 4 multiplied by N random numbers in a range of-0.5 by using a uniformly distributed random number generation method, wherein each 4 random numbers are used as a group for determining the direction and offset of coordinates { xi, yi } of each circle with the radius of R1, and the change amplitude of the coordinates is less than 0.5 times of R2; step 1.3): screening and removing coordinates of which the variation amplitude of the unqualified coordinates is less than 0.5 time of R2, and regenerating the unqualified coordinates;

step 1.4): and (4) taking the finally obtained coordinates as a circle center and R1 as a radius to manufacture the photoetching plate.

According to the scheme, the conventional vertical cavity surface emitting epitaxial material comprises a substrate, a lower Bragg reflection layer, an active region, an oxidation limiting layer, an upper Bragg reflection layer and a contact layer which are sequentially stacked from bottom to top.

According to the scheme, the transparent dielectric layer in the step 6) is made of silicon nitride or silicon dioxide, and the thickness is 100-400 nm.

According to the scheme, the step 7) is specifically as follows: etching the depth of the high-order mode selective inhibition structure pattern to meet the quarter-wavelength phase cancellation condition; a circular ring pattern is adopted for inhibiting the high-order modes LP13 and LP12, a 4-month tooth pattern is adopted for inhibiting the LP11 mode, and a ring-shaped wedge pattern is adopted for inhibiting the high-order modes except the fundamental mode LP 01.

The invention has the following beneficial effects:

the random arrangement of the circular truncated cones of the light-emitting units has the characteristic of local limitation, and the preparation process is not influenced;

the light emitting unit mode selection is realized in each light emitting unit circular truncated cone through a high-order mode selection inhibition structure, light spot patterns are controlled, the light emitting unit circular truncated cone can be used for a structural light source for three-dimensional image recognition, the high-order mode inhibition is realized by controlling the light field coherence cancellation through the thickness of a transparent medium layer at a specific position, and the light output efficiency is not influenced;

and thirdly, the invention uses mature semiconductor technology, completes the manufacture at the chip stage, greatly reduces the cost, reduces the components and improves the stability of the module.

Drawings

FIG. 1 is a schematic diagram of the overall structure of an embodiment of the present invention;

FIG. 2 is a schematic cross-sectional view along the diameter of the circular table of the light-emitting unit according to the embodiment of the present invention;

FIG. 3 is a high-order mode selective suppression structure pattern for the high-order mode suppression of LP13 and LP12 in the present embodiment;

FIG. 4 is a high order mode selection suppression structure pattern for suppression of the LP11 mode in this embodiment;

fig. 5 shows a pattern of the high-order mode selective suppression structure for suppressing the high-order mode other than the fundamental mode LP01 in this embodiment.

Reference numerals: 1. an N electrode layer; 2. a substrate; 3. a lower Bragg reflection layer; 4. an active region; 5. an oxidation limiting layer; 501. oxidizing the pore diameter; 6. an upper Bragg reflection layer; 7. a contact layer; 8. a P electrode layer; 9. a transparent dielectric layer; 901. etching the pattern; 10. an insulating layer; 100. the light-emitting unit round platform.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

Referring to fig. 1 to 5, the present invention is a high-order mode selective suppression type vertical emission laser, which includes an N electrode layer 1, a substrate 2 disposed on the N electrode layer 1, a lower bragg reflective layer 3 (lower DBR layer) disposed on the substrate 2, and light-emitting unit circular truncated cones 100 randomly and uniformly distributed on the lower bragg reflective layer 3, wherein the light-emitting unit circular truncated cones 100 form a random unit array, and a gap is disposed between two adjacent light-emitting unit circular truncated cones 100; wherein, the light emitting unit round table 100 includes: the active region 4 is arranged on the lower Bragg reflection layer 3, the oxidation limiting layer 5 is arranged on the lower Bragg reflection layer 3, the center of the oxidation limiting layer is provided with an oxidation aperture 501, the upper Bragg reflection layer 6 (upper DBR layer) is arranged on the oxidation limiting layer 5, the contact layer 7 is arranged on the upper Bragg reflection layer 6, the P electrode layer 8 is arranged on the contact layer 7, and the transparent medium layer 9 is arranged on the contact layer 7, the transparent medium layer 9 is provided with different etching patterns 901 to form a high-order mode selection inhibiting structure, and the etching depth of the high-order mode selection inhibiting structure etching pattern 901 meets the quarter wavelength phase cancellation condition; the middle part of the oxidation limiting layer 5 is not oxidized, and two sides of the oxidation aperture 501 are oxidation areas; fig. 1 is a schematic diagram of a light-emitting unit circular table 100 forming a random unit array, the light-emitting unit circular table 100 and an outer region being externally wrapped with an insulating layer 10 and a P electrode layer 8; the P electrode layer 8 wraps the light-emitting unit round platform 100 and the outer area, an opening of the P electrode layer 8 positioned in the middle of the upper portion of the light-emitting unit round platform 100 forms an upper electrode window, and the transparent medium layer 9 is arranged at the upper electrode window; the P electrode layer 8 at the outer edge of the upper electrode window is contacted with the contact layer 3; an insulating layer 10 is provided between the light emitting unit round table 100 and the region other than the light emitting unit round table and the P electrode layer 8.

Referring to fig. 2 to 5, the high-order mode selective suppression structure is implemented by etching the inside of each light emitting unit circular truncated cone 100 to a specified thickness through a special etching pattern 901 to achieve phase cancellation of the high-order mode and suppress lasing thereof, specifically: a ring pattern is adopted for inhibiting the LP13 and LP12 high-order modes, a 4-month tooth pattern is adopted for inhibiting the LP11 mode, and a ring-shaped wedge pattern is adopted for inhibiting the high-order modes except the fundamental mode; the combined application of several patterns achieves selective suppression of the pattern.

In the embodiment of the present invention, the substrate 2 is made of GaAs or InP.

The lower Bragg reflection layer 3 comprises 30-50 pairs of Al0.1GaAs/Al0.9GaAs reflection layers, the optical thickness of each layer is one-fourth laser lasing wavelength, and two sub-layers of each pair of reflection layers have gradually-increased componentsChanging the characteristics; the DBR is lightly doped at two pairs adjacent to the active region, and has an N-doping concentration no greater than 5 x 10^17/cm³The doping concentration range of other lower DBRs is 5 x 10^17/cm³～5×10^18/cm³。

The active region 4 is of a multi-quantum well structure of InGaAs/GaAs, InGaAs/AlGaAs, InGaAs/GaAsP and the like, and the central wavelength of an emission spectrum is matched with the lasing wavelength of the laser. Matching layers are arranged on the upper side and the lower side of the multiple quantum well and used for adjusting the cavity mode wavelength.

The material of the oxidation limiting layer 5 is AlGaAs, the Al component is 0.95-0.99, and the layer can form Al under the condition of high-temperature wet oxygen₂O₃And the insulating layer changes from high refractive index of about 3 to low refractive index of about 1.75 so as to limit current and an optical field.

The upper Bragg reflection layer 6 comprises 10-30 pairs of Al0.1GaAs/Al0.9GaAs reflection layers, the optical thickness of each layer is one-fourth laser lasing wavelength, and two sub-layers of each pair of reflection layers have component gradual change characteristics; the DBR is lightly doped in two pairs adjacent to the active region, and has a P doping concentration no greater than 5 x 10^17/cm³The doping concentration range of other upper DBRs is 5 x 10^17/cm³～5×10^18/cm³。

The contact layer 7 is a P-type highly doped GaAs material with the thickness of 5-50 nm and the doping concentration of 1 x 10^19/cm³～5×10^19/cm³。

The invention also comprises a preparation method of the high-order mode selection inhibition type vertical surface emitting laser, which comprises the following steps:

step 1): preparing a photoetching plate for photoetching the circular truncated cone 100 of the light-emitting unit, and arranging the random unit array; the method specifically comprises the following steps:

step 1.1): setting the radius of the circular truncated cone 100 of the light-emitting unit as R1, firstly, carrying out close packing arrangement on a circle with the radius of R1+ R2 in the whole array region to obtain the center coordinates { xi, yi } and the total number N of the circle with the radius of R1+ R2, wherein R2 is a positive number;

step 1.2): generating random numbers in a range of 4 multiplied by N-0.5 by using a uniformly distributed random number generation method, determining the directions and the offsets of coordinates { xi, yi } of a group of circles with the radius of R1, wherein the coordinate change amplitude is less than 0.5 times of R2;

step 1.3): screening according to the process and the random distribution effect, removing the coordinates of which the variation amplitude of the unqualified coordinates is less than 0.5 time of R2, and generating the qualified coordinates again;

step 1.4): manufacturing a photoetching plate by taking the finally obtained randomly distributed coordinates as a circle center and R1 as a radius;

step 2): a photoetching plate is utilized to photoetch the light-emitting unit circular truncated cone 100 on the conventional vertical cavity surface emission epitaxial material, and the outer area of the circular truncated cone is etched to be below the active area 4 of the epitaxial material; the conventional vertical cavity surface emitting epitaxial material comprises a substrate 2, a lower Bragg reflection layer 3, an active region 4, an oxidation limiting layer 5, an upper Bragg reflection layer 6 and a contact layer 7 which are sequentially stacked from bottom to top;

step 3): oxidizing the high-alumina component layer by using high-temperature wet oxygen to form an oxidized aperture, and limiting a current and an optical field;

step 4): growing an insulating layer 10 and corroding an upper electrode window; the insulating layer material is generally silicon dioxide or silicon nitride;

step 5): photoetching and metal stripping to form a P electrode layer 8;

step 6): covering a transparent medium layer 9; the transparent dielectric layer 9 is made of silicon nitride or silicon dioxide, and the thickness is 100-400 nm;

step 7): photoetching and etching the high-order mode selection inhibition structure etching pattern 901 of each light-emitting unit circular truncated cone 100; the depth of the high-order mode selective inhibition structure etching pattern 901 meets the quarter-wavelength phase cancellation condition; a ring pattern is adopted for inhibiting the LP13 and LP12 high-order modes, a 4-month tooth pattern is adopted for inhibiting the LP11 mode, and a ring-shaped wedge pattern is adopted for inhibiting the high-order modes except the fundamental mode LP 01;

step 8): thinning the wafer;

step 9): and evaporating the N electrode layer 1 and annealing.

The random unit arrays of the vertical cavity surface emitting laser are distributed, and the distribution of the random unit arrays has the local limiting characteristic and does not influence the preparation and processing of the process; the high-order mode selective inhibition of each light-emitting unit circular truncated cone 100 and the realization method of the high-order mode selective inhibition structure in each light-emitting unit circular truncated cone 100 are characterized in that the high-order mode inhibition is realized by controlling the coherent cancellation of a light field through the thickness of a transparent medium layer at a specific position, namely the thickness of an etching pattern, so that the light output efficiency is not influenced; the invention prepares the vertical cavity surface emitting laser random unit array, and the preparation realization method is the preparation process steps adopted for meeting the characteristics of random distribution of the random unit array and the phase control of the graphical film of each circular table 100 of the light-emitting unit; the invention has the characteristics of low cost, compact structure and reliable performance.

The foregoing is a more detailed description of the present invention that is presented in conjunction with specific embodiments, and the practice of the invention is not to be considered limited to those descriptions. For those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention.