Dispersion management for optical parametric amplifiers in midinfrared

Abstract

Midinfrared (MIR) is an attractive spectral region for many applications ranging from vibrational spec-troscopy to attosecond physics. However, in this spectral region, the dispersion management techniques are not asmature as the ones in the near-infrared (NIR) or visible, which is a key ingredient of ultrafast laser technology. In thismanuscript, 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 compressoris proposed and numerically analyzed. As a case study, the proposed scheme is applied numerically to a 2-μm pumpedtwo-stage optical parametric amplifier (OPA) system at 4.06 μm. In the model OPA system, the seed pulses are generatedby white-continuum in bulk crystal and then amplified via zinc germanium phosphide (ZGP)-based OPAs. Parametricgain bandwidth of the ZGP nonlinear crystal is numerically studied. According to the numerical simulations, 3-mmcrystal supports pulses with 26.5 fs pulse duration (FWHM) at 4.06 μm. With the proposed dispersion managementscheme, the seed pulses are first stretched inside a Martinez grating stretcher to 1.4–1.6 ps for efficient amplification inOPA stages and then compressed down to the transform-limit inside CaF2bulk material.