Study on the spectral characteristics of the cascaded parametric conversion in a single cavity tandem multi-channel PPMgLNs-based optical parametric oscillator

Abstract

We report an acousto-optic Q-switched Nd:GdVO4 laser pumped flexibly tunable cascaded optical parametric oscillator (OPO) based on two separate multi-channel periodically poled magnesium oxide doped Lithium Niobate (PPMgLN). Even under lower pump power, long wavelength parametric output was found to be more easily generated than in single stage OPO. A cascaded idler output at 5.075 μm was found to be generated. A convenient method to monitor the occurring of the cascaded parametric process was also presented by measuring the spectrum of sum-frequency generation of the pump power and the cascaded signal power.