Generation of 8 μm radiation in a ZnGeP2 single crystal at a difference frequency, with pumping by telecommunication-band radiation of 1.5 μm and radiation at a wavelength of 1.908 μm

Abstract

This study theoretically investigates difference frequency generation in a ZnGeP2 crystal pumped by a fiber laser (1.53 μm) and a Tm:YLF laser (1.908 μm) for generating mid-infrared radiation. The theoretical model incorporates phase matching conditions, nonlinear susceptibility, crystal length, and beam parameters (sum of the average power of the pump wave and signal wave and the pulse duratio)to estimate the generated pulse and average power. The impact of absorption and pulse duration on the output power is analyzed. Results indicate that increasing pump power and decreasing pulse duration enhance the average output power. The study provides a theoretical framework for designing efficient difference frequency generation-based mid-infrared sources.