Amplification of mid-IR continuum for broadband 2D IR spectroscopy

We report the generation and characterization of micro -joule level, broad bandwidth femtosecond pulses in the mid-infrared (MIR) using optical parametric amplification of continuum MIR seed pulses in GaSe. The signal (3 mu m) and idler (6 mu m) pulses have energies of 6 mu J and 3 mu J with bandwidths of similar to 950 cm-1 and 650 cm-1 FWHM and pulse lengths of 34 fs and 80 fs. Broadband 2D IR spectra of O-H and N-H transitions are acquired with the signal beam demonstrating the capabilities of this source for cross peak and line shape measurements. (c) 2023 Optica Publishing Group