Random quasi-phase-matched second-harmonic eneration in periodicaly poled lithium tantalate

S. Stivala, . C. Busacca, A. Pasquazi, R. Olivieri, R. Morandotti, and G. Assanto

Opt. Lett. 35, 363-365 (2010)

Abstract:

We observe second harmonic generation via random quasi-phase-matching in a 2.0 m periodically poled, 1-cm-long, z-cut lithium tantalate. Away from resonance, the harmonic output profiles exhibit a characyeristic pattern scattering from a stochastic domain distribution and a quadratic growth with a fundmental excitation, as well as broadband spectral response. The results are in good agreement with a simple model and numerical simulations in the undepleted regime, assuming an anisotropic spread of the random nonlinear component.