Technology of cavity fabrication for whispering gallery modes laser ([λ ∼ 3-4μm)

Abstract

Different wet-etching solutions based on CrO 3; HClO 4 and HBr for materials lattice-matched to InAs for whispering gallery modes (WGM) lasers (3-4μm) disk cavities fabrication were studied. In the case of WGM-laser cavity - it is crucial to have vertical and smooth sidewalls, free from roughness and other irregularities. Perfect circular disk cavities with diameter from 50 to 300μm were obtained by using HBr-based wet-etching technology. At a total cavity height reaching 30μm, the vertical part of the sidewalls was about 10μm. Based on the obtained disk cavities, WGM lasers are created that produce coherent radiation with a wavelength of λ≈(3.0-3.5)μm in a continuous regime at 77K and in a pulsed regime up to 125K. © 2011 Springer Science+Business Media B.V.