Scanning second-harmonic/third-harmonic generation microscopy of gallium nitride

Abstract
Scanning second-harmonic generation and third-harmonic generation microscopy of a gallium nitride (GaN) sample was demonstrated using a femtosecond Cr:forsterite laser. Taking advantage of the electric-field enhanced second-harmonic generation effect and bandtail state resonance effect, the obtained second-harmonic and third-harmonic generation microscopic images revealed the piezoelectric field and bandtail state distributions in a GaN sample.