Optical pumping for high-power ultrashort LWIR gas lasers

Abstract

Long-wave infrared (LWIR) lasers based on high-voltage pulsed discharges in the high-pressure CO2 gas have reached multi-TW peak power. As optical pumping appears to be a more viable pathway toward ultrahigh power and high repetition rate, we investigated multiple apparatus including direct and indirect optical pumping. Indirect optical pumping through stimulated Raman scattering in N2 gas could be efficient, and is relatively insensitive to the pump wavelength. On the other hand, laser technologies for direct optical pumping have higher maturity levels at wavelengths of ~ 1.4 µm and ~ 2.0 µm among multiple excitation bands in the mid-IR wavelength.