Suppression of interference-induced reflectivity fluctuations in GaN-based semiconductor saturable absorber mirror

Abstract

Simulations and experiments were carried out to suppress the interference-induced reflectivity fluctuations in a nonmonolithically grown broad-band GaN-based semiconductor saturable absorber mirror (SESAM). Laser lift-off of the sapphire substrate, inductively coupled plasma etching of the GaN buffer, and plasma enhanced chemical vapor deposition of the antireflective coating were conducted according to the simulated optimization processes. The interference-induced reflectivity fluctuations were effectively reduced. Characterizations by atomic force microscopy, X-ray diffraction, scanning electron microscopy, and photoluminescence further indicated that the SESAM after the optimization processes exhibited a good surface morphology, crystal quality, and emission property. © 2008 The Electrochemical Society.