Generation of Multicolor Pulse Bursts for Pumping Long-Wave Infrared Optical Parametric Amplifiers

Abstract

High-peak-power mid- and long-wave infrared (MWIR and LWIR) optical parametric chirped pulse amplifiers (OPCPAs) based on highly nonlinear ZGP crystals operating above the wavelength of 5 μm require high-energy picosecond pump pulses centered at wavelengths exceeding 2 μm [1]. These can be generated directly in laser amplifiers, based on Ho-doped or Cr-doped crystals or in cascaded optical parametric amplifiers (OPAs). As pump sources for the 2-μm OPAs, laser systems operating in the vicinity of 1-μm are optimal, since both the signal and the idler pulses from the OPA can be used for subsequent pumping of ZGP crystals. For the generation of high-energy picosecond pulses around 1 μm Nd-doped laser amplifiers are predominantly employed. However, energy scaling in these amplifiers is limited, as chirped pulse amplification (CPA) technique [2] is hardly applicable because of the narrow amplification bandwidth.