Nonlinear Optodynamics of GaN Thin Films: Transient Saturation Absorption Unveiled

This research elucidates the nonlinear optodynamics of GaN thin films through a comprehensive analysis of the degenerate transient absorption process under varying pump intensities. Our findings indicate that upon photon absorption, electrons transition from the valence band to the conduction band. The valence band's larger absorption cross-section compared to the conduction band leads to the observed transient saturation absorption in GaN thin films.