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

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.