Dispersion management for optical parametric amplifiers in midinfrared

Abstract

Midinfrared (MIR) is an attractive spectral region for many applications ranging from vibrational spectroscopy to attosecond physics. However, in this spectral region, the dispersion management techniques are not as mature as the ones in the near-infrared (NIR) or visible, which is a key ingredient of ultrafast laser technology. In this manuscript, the transfer of dispersion management schemes for optical parametric (chirped pulse) amplifiers (OP(CP)As) from NIR to MIR is discussed. Among those, a scheme based on Martinez-type grating stretcher and a bulk compressor is proposed and numerically analyzed. As a case study, the proposed scheme is applied numerically to a 2-μm pumped two-stage optical parametric amplifier (OPA) system at 4.06 μm. In the model OPA system, the seed pulses are generated by white-continuum in bulk crystal and then amplified via zinc germanium phosphide (ZGP)-based OPAs. Parametric gain bandwidth of the ZGP nonlinear crystal is numerically studied. According to the numerical simulations, 3-mm crystal supports pulses with 26.5 fs pulse duration (FWHM) at 4.06 μm. With the proposed dispersion management scheme, the seed pulses are first stretched inside a Martinez grating stretcher to 1.4–1.6 ps for efficient amplification in OPA stages and then compressed down to the transform-limit inside CaF2 bulk material.