Interference in reflected second-harmonic generation from thin nonlinear films

Abstract
We have observed interference in reflected second-harmonic generation from two adjoined nonlinear slabs. Experimental results on ZnSe/GaAs(001) heterostructures are obtained and compared to theoretical calculations of the phenomena. Together, the experiments and calculations enable us to deduce the frequency-dependent bulk nonlinear susceptibility for ZnSe near the E0 transition.