Lasing in cuprous iodide microwires

Abstract

We report on the observation of lasing in cuprous iodide (CuI) microwires. A vapor-phase transport growth procedure was used to synthesize CuI microwires with low defect concentration. The crystal structure of single microwires was determined to be of zincblende-type. The high optical quality of single microwires is indicated by the observed series of excitonic emission lines as well as by the formation of gain under optical excitation. Lasing of triangular whispering-gallery modes in single microwires is demonstrated for fs- and ns-excitation from cryogenic temperatures up to 200 K. Time-resolved micro-photoluminescence studies reveal the dynamics of the laser process on the time scale of several picoseconds.