Efficiency-enhanced mid-wave infrared beam generation at 3.8 mu m with a seeded optical parametric generator

In this paper, we model the performance of a device with a simple architecture for high-power mid-wave infrared beam generation at a wavelength of 3.8 microns. The device is a seeded idler efficiency-enhanced optical parametric generator (IEE-OPG) based on an aperiodically poled MgO-doped LiNbO3 (APMgLN) grating pumped by a high-repetition rate nanosecond-pulsed 1064-nm laser and seeded by a low-power 1478-nm distributed feedback diode laser. In the IEE-OPG, two optical parametric amplification (OPA) processes, OPA-1 and OPA-2, are simultaneously phase matched in a single APMgLN grating. The signal at 1478 nm is amplified and the idler at 3800 nm is generated as a result of OPA-1, the signal acts as the pump for OPA-2 and the conversion efficiency of the idler is enhanced as a result of OPA-2. Also, a difference-frequency beam at 2418 nm is generated.