GaN-based echo wall laser based on porous DBR, and preparation method and application thereof

Abstract

The invention discloses a GaN-based echo wall laser based on a porous DBR, and a preparation method and application thereof. The GaN-based echo wall laser comprises a substrate, a buffer layer, a porous DBR layer, an n-type doped GaN layer, an active layer, an electron blocking layer and ap-type doped GaN layer, wherein the buffer layer is arranged on the substrate, and the periphery of the buffer layer is etched downwards to form a protruding part; the porous DBR layer is arranged on the protruding part and plays a role in limiting a light field; the n-type doped GaN layer is arranged on the porous DBR layer; the active layer is arranged on the n-type doped GaN layer; the electron blocking layer is arranged on the active layer; and the p-type doped GaN layer is arranged on the electron blocking layer. The bottom porous DBR reflector adopted by the invention has a good vertical limiting effect on the light field of the echo wall microcavity, leakage of part of the light field to the direction of the substrate cannot be caused, and the threshold power density of the prepared echo wall laser is relatively low.

Description

technical field [0001] The invention belongs to the field of laser light sources, and in particular relates to a porous DBR-based GaN-based whispering gallery laser, its preparation method and application. Background technique [0002] With the rapid development of information, the integration of electronic chips continues to increase, but the interconnection parasitic effect caused by this will cause signal delay, which is a bottleneck that cannot be ignored in further improving information transmission and processing. The optoelectronic integration that uses light as a carrier for information processing can perform better and faster information processing because it is not affected by the parasitic effects of electrical interconnection. For optoelectronic integration technology, on-chip integrated lasers can provide high-efficiency light sources for optical systems to ensure normal signal transmission. light source. Whispering gallery lasers have become an ideal light so...

AI Technical Summary

Problems solved by technology

In order to improve the light confinement ability of GaN-based whispering gallery resonators, there are two main technical approaches: one is to use epitaxy to grow GaN / Al X Ga 1-x N (aluminum gallium nitride) superlattice is used as a Bragg reflector. However, due to the 2.4% lattice mismatch between GaN and AlN (aluminum nitride), epitaxy is relatively difficult, and the problem is more severe at high Al composition. serious

In addition, in order to achieve high reflectivity of the mirror, the low refractive index difference often needs to be compensated by increasing the number of DBR (aluminum nitride) cycles, and the GaN / AlGaN DBR with multiple cycles of epitaxy will further increase the difficulty of epitaxy

In addition, the refractive index difference of the vertical interface can be increased by introducing an air gap under the active region with the help of GaN selective etching, but there are still some problems

First of all, for the whispering gallery resonator whose substrate is sapphire, an additional InGaN (Indium Gallium Nitride) superlattice needs to be designed under the active region. extensional difficulty

Secondly, the contact area between the supporting material connecting the microdisk and the substrate and the microdisk is very small, and the electrical and thermal contact is poor, which is not conducive to the later realization of electrical devices.

At the same time, part of the mode will also leak into the substrate along the support material.

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