阅读说明：本技术 外延集成介质膜dbr外腔面发射激光器 (Epitaxial integrated dielectric film DBR external cavity surface emitting laser ) 是由 徐晨 吴博 解意洋 傅攀 赵旭鹏 于 2021-01-16 设计创作，主要内容包括：本发明公开了外延集成介质膜DBR外腔面发射激光器,包括P型金属电极层、钝化层、周期交替生长的上分布式布拉格反射镜、高铝组分的氧化限制层、有源区、周期生长的下分布式布拉格反射镜、GaAs衬底层、N型金属电极层、电流限制氧化孔、相位匹配层、腔长匹配层、氧化硅氮化硅介质膜分布式布拉格反射镜和出光孔；本发明中采用生长相位匹配层、腔长匹配层的方法延长垂直腔面发射激光器的固有腔长,通过感应耦合等离子体增强气相沉积的方法外延氧化硅氮化硅介质膜分布式布拉格反射镜,达到控制光偏振的同时压窄线宽。本发明降低半导体激光器阈值,提高了器件的成品率。(The invention discloses an epitaxial integrated dielectric film DBR (distributed Bragg reflector) external cavity surface emitting laser, which comprises a P-type metal electrode layer, a passivation layer, an upper distributed Bragg reflector which alternately grows in a period, an oxidation limiting layer of a high-aluminum component, an active region, a lower distributed Bragg reflector which grows in a period, a GaAs substrate layer, an N-type metal electrode layer, a current limiting oxidation hole, a phase matching layer, a cavity length matching layer, a silicon oxide and silicon nitride dielectric film distributed Bragg reflector and a light outlet hole; the invention adopts the method of growing the phase matching layer and the cavity length matching layer to prolong the inherent cavity length of the vertical cavity surface emitting laser, and the silicon oxide silicon nitride dielectric film distributed Bragg reflector is extended by the method of inductively coupled plasma enhanced vapor deposition to control the light polarization and narrow the line width at the same time. The invention reduces the threshold value of the semiconductor laser and improves the yield of the device.)

1. Dielectric film distributed Bragg reflector external cavity surface emitting laser, its characterized in that: the external cavity surface emitting laser comprises a P-type electrode (1), a passivation layer (2), an upper distributed Bragg reflector (3) which grows periodically and alternately, a high-aluminum component oxidation limiting layer (4), an active region (5), a lower distributed Bragg reflector (6) which grows periodically and alternately, a GaAs substrate layer (7), an N-type electrode (8), a current limiting oxidation hole (9), a phase matching layer (10), a cavity length matching layer (11), a silicon oxide silicon nitride dielectric film distributed Bragg reflector (12) and a light outlet hole (13); the upper distributed Bragg reflector (3) with periodic alternate growth, the oxidation limiting layer (4) with high aluminum component, the active region (5), the lower distributed Bragg reflector (6) with periodic alternate growth and the GaAs substrate layer (7) are sequentially arranged from top to bottom, and the outer sides of the upper distributed Bragg reflector (3), the oxidation limiting layer (4) with high aluminum component, the active region (5), the lower distributed Bragg reflector (6) with periodic alternate growth and the GaAs substrate layer (7) are coated by the passivation layer (2); the middle of the oxide layer (4) with high aluminum component is provided with a current limiting oxidation hole (9); the top of the upper distributed Bragg reflector which grows periodically and alternately is provided with a light outlet (13), and the top of the light outlet (13) is sequentially provided with a phase matching layer (10), a cavity length matching layer (11) and a dielectric film distributed Bragg reflector (12); the passivation layer (2) is arranged on the side wall of the laser, the P-type electrode (1) is arranged on the passivation layer (2), and the passivation layer (2) and the GaAs substrate (7) are arranged on the N-type electrode (8) in a sharing mode.

2. The epi-integrated dielectric film dbr external cavity surface emitting laser of claim 1, wherein: the size of the current limiting oxidation hole (9) is 5-12 um; the phase matching layer (10) and the cavity length matching layer (11) deposit a dielectric layer on a common vertical cavity surface emitting laser device through a plasma enhanced chemical vapor deposition, magnetron sputtering or MOCVD process; the thicknesses of the phase matching layer (10) and the cavity length matching layer (11) are integral multiples of quarter of the working wavelength of the laser, and the specific thicknesses are designed according to the line width of a device.

3. The epi-integrated dielectric film dbr external cavity surface emitting laser of claim 1, wherein: the dielectric film distributed Bragg reflector (12) with the period alternately growing is obtained by inductively coupled plasma enhanced chemical vapor deposition epitaxial growth, the thickness is one fourth of the working wavelength of the laser, and the specific thickness is designed according to the line width of a device.

4. The epi-integrated dielectric film dbr external cavity surface emitting laser of claim 1, wherein: the dielectric film distributed Bragg reflector structure designs the material thickness of the reflector.

5. A process for preparing an epitaxial integrated dielectric film distributed bragg reflector external cavity surface emitting laser using the laser of claim 1, characterized by: growing a 850nm epitaxial wafer by MOCVD, depositing silicon oxide by ICPCVD, photoetching and corroding a mesa graph, etching the mesa by using ICP to expose an oxidation limiting layer (4) of a high-aluminum component, oxidizing a current limiting oxidation hole (9) by a wet method, growing a passivation layer (2) by using ICPCVD, etching a light outlet hole (13) by photoetching, manufacturing a P-type electrode (1) by thermal evaporation and stripping, manufacturing an N-type electrode (8) by magnetron sputtering, and obtaining the common oxidized vertical cavity surface emitting laser; depositing a dielectric layer on a common vertical cavity surface emitting laser device by an inductively coupled plasma enhanced chemical vapor deposition and stripping method to form a phase matching layer (10), a cavity length matching layer (11) and a dielectric film distributed Bragg reflector (12), and obtaining the epitaxial integrated dielectric film distributed Bragg reflector outer cavity surface emitting laser.

Technical Field

The invention belongs to the technical field of semiconductor lasers, and particularly relates to an epitaxial integrated dielectric film DBR outer cavity surface emitting laser.

Background

Vertical Cavity Surface Emitting Lasers (VCSELs) are widely used in the fields of optical communication, laser radars, integrated chip systems and the like due to their characteristics of miniaturization, low power loss, fast modulation response, continuous beam output and the like. In a common oxidized vertical cavity surface emitting laser, due to the characteristics of anisotropy of an oxidized limiting layer material, anisotropy of active area material gain and the like, the polarization of the laser is uncertain or unstable, and due to the change of the temperature of an active area, the polarization of the laser can be unstable; secondly, in the oxide-confined vertical surface-emitting laser, it is difficult to narrow the spectral linewidth to 100MHz, usually in the range of several hundred MHz, due to the short photon lifetime. The characteristics seriously affect the light-emitting quality of the vertical cavity surface emitting laser and prevent the application of the vertical cavity surface emitting laser in high-precision systems such as an atomic microsystem and the like. Based on the above problems, a method for performing epitaxy on a vertical cavity surface emitting laser is provided to achieve the purposes of narrowing the line width and controlling polarization. For the vertical cavity surface emitting laser, the spectral line width can be reduced by increasing the effective cavity length of the laser, and for the common vertical cavity surface emitting laser, the size of the effective cavity length is determined by the upper and lower distributed Bragg reflectors, which are determined after the epitaxial wafer grows. In the invention, the ICPCVD is used for extending silicon oxide and silicon nitride on the VCSEL chip to form the dielectric film distributed Bragg reflector, so that the external cavity is prolonged, the polarization is controlled at the same time, and finally the narrow-spectral-line-width integrated external cavity surface emitting laser in a stable polarization mode is obtained.

Disclosure of Invention

The invention adopts the method of growing the phase matching layer and the cavity length matching layer to prolong the inherent cavity length of the vertical cavity surface emitting laser, and the silicon oxide silicon nitride dielectric film distributed Bragg reflector is extended by the method of inductively coupled plasma enhanced vapor deposition to control the light polarization and narrow the line width at the same time.

The technical scheme adopted by the invention is that the outer cavity surface emitting laser of the epitaxial integrated dielectric film DBR comprises a P-type metal electrode layer (1), a passivation layer (2), an upper distributed Bragg reflector (3) which grows periodically and alternately, an oxidation limiting layer (4) of a high-aluminum component, an active region (5), a lower distributed Bragg reflector (6) which grows periodically, a GaAs substrate layer (7), an N-type metal electrode layer (8), a current limiting oxidation hole (9), a phase matching layer (10), a cavity length matching layer (11), a silicon oxide silicon nitride dielectric film distributed Bragg reflector (12) and a light outlet hole (13); the upper distributed Bragg reflector (3) with periodic alternate growth, the oxidation limiting layer (4) with high aluminum component, the active region (5), the lower distributed Bragg reflector (6) with periodic alternate growth and the GaAs substrate layer (7) are sequentially arranged from top to bottom, and the outer sides of the upper distributed Bragg reflector (3), the oxidation limiting layer (4) with high aluminum component, the active region (5), the lower distributed Bragg reflector (6) with periodic alternate growth and the GaAs substrate layer (7) are coated by the passivation layer (2); the middle of the oxide layer (4) with high aluminum component is provided with a current limiting oxidation hole (9); the top of the upper distributed Bragg reflector which grows periodically and alternately is provided with a light outlet (13), and the top of the light outlet is sequentially provided with a phase matching layer (10), a cavity length matching layer (11) and a dielectric film distributed Bragg reflector (12); the passivation layer (2) is arranged on the side wall of the laser, the P-type electrode (1) is arranged on the passivation layer (2), and the passivation layer (2) and the GaAs substrate (7) are arranged on the N-type electrode (8) together.

The VCSEL current limiting oxidation hole is 5-12 microns in size, a dielectric layer is deposited on a common vertical cavity surface emitting laser device through a phase matching layer (10) and a cavity length matching layer (11) through a plasma enhanced chemical vapor deposition, magnetron sputtering or MOCVD process, the thicknesses of the phase matching layer (10) and the cavity length matching layer (11) are integral multiples of one fourth of the working wavelength of the laser device, and the specific thickness is designed according to the line width of the device. The silicon oxide/silicon nitride distributed Bragg reflector (12) with the period alternately growing is obtained by inductively coupled plasma enhanced chemical vapor deposition epitaxial growth, the thickness is one fourth of the working wavelength of the laser, and the specific thickness is designed according to the line width of a device.

The integrated external cavity surface emitting laser with high beam quality is prepared by the method, and the effective cavity length and the line width are narrowed by depositing the cavity length matching layer. The dielectric film distributed Bragg reflector is obtained by an epitaxial method, and polarization is stabilized.

Compared with the prior art, the invention has the following advantages:

1. the adoption of the external cavity matching medium layer and the phase matching layer can not only increase the original cavity length, but also obtain the lattice stress release to relieve the lattice mismatch problem.

2. The dielectric film distributed Bragg reflector can increase high reflection characteristics and reduce the threshold value of the semiconductor laser.

3. The mode of obtaining the integrated external cavity by adopting an epitaxial method realizes stable polarization and narrow line width, and the laser can be prepared by a simpler plane processing process, so that the yield of devices is improved.

Drawings

FIG. 1 is a schematic view of a conventional oxide vertical cavity surface emitting laser

FIG. 2 is a schematic diagram of an integrated external cavity surface emitting laser with high beam quality

In the figure: 1. a P-type electrode; 2. a passivation layer; 3. an upper distributed Bragg reflector alternately grown periodically; 4. an oxidation limiting layer of a high aluminum composition; 5. an active region; 6 periods of alternately growing lower distributed Bragg reflectors; 7. a GaAs substrate layer; 8. an N-type electrode; 9. a current limiting oxide pore; 10. a phase matching layer; 11. a cavity length matching layer; 12. a dielectric film distributed Bragg reflector which grows periodically and alternately; 13. and a light outlet.

Detailed Description

As shown in fig. 1 and 2, growing a 850nm epitaxial wafer by MOCVD, depositing silicon oxide by ICPCVD, photoetching and etching a mesa pattern, etching a mesa by ICP, exposing an oxidation limiting layer (4) of a high-aluminum component, oxidizing a current limiting oxidation hole (9) by a wet process, growing a passivation layer (2) by ICPCVD, etching a light outlet hole (13) by photolithography, manufacturing a P-type electrode (1) by thermal evaporation and stripping, manufacturing an N-type electrode (8) by magnetron sputtering, and obtaining a common oxidized vertical cavity surface emitting laser (fig. 1); depositing a dielectric layer on a common vertical cavity surface emitting laser device by an inductively coupled plasma enhanced chemical vapor deposition and stripping method to form a phase matching layer (10), a cavity length matching layer (11) and a dielectric film distributed Bragg reflector (12), and obtaining the epitaxial integrated dielectric film distributed Bragg reflector outer cavity surface emitting laser (figure 2).