Simultaneous observation of second-harmonic emission and three-photon excited photoluminescence from hybrid vapor phase epitaxy-grown GaN film

Abstract

Nonlinear optical properties of the undoped hybrid vapor phase epitaxy-grown (GaTN film sample) were investigated and analyzed using a tunable femtosecond laser as an excitation source. As the laser wavelength was tuned from 762-796 nm, the sample emitted signals corresponding to the second-harmonic wavelength from 381-398 nm with a quadratic power dependence. A strong three-photon-process-related signal at 367 nm with cubic power dependence was simultaneously observed for the first time.