Optically pumped GaN-based vertical cavity surface emitting laser with strain-compensated AlGaN/InGaN distributed Bragg reflector

We proposed a strain-compensated distributed Bragg reflector (DBR) with high reflectivity and a practical growth time. The DBR consists of AlGaN/GaN multilayer as the low refractive index layer and InGaN as the high refractive index layer. The DBR was grown on c-plane GaN substrate as an asymmetric structure with InGaN thicker than lambda/4. By growing each layer at >= 1 mu m h-1 and minimizing interruptions, a 60.5-period DBR with a center wavelength of 441.8 nm and nearly 100% peak reflectivity was achieved in about 5 h. A VCSEL with the strain-compensated DBR was fabricated, and the clear threshold characteristic was confirmed by optical pumping.