Low threshold GaInAsP lasers with semiconductor/air DBR fabricated by inductively coupled plasma etching

We fabricated GaInAsP lasers with a semiconductor/air DBR by the ICP etching and obtained the normalized lasing threshold of 3 mA//spl mu/m. The FDTD simulation indicates that the crucial factor for high reflectivity is the sidewall angle much higher than 85 degrees. Now, we are optimizing the inductively coupled plasma (ICP) condition for high yield fabrication of the vertical DBR.