Development two-stage frequency domain optical parametric amplification

Abstract From experiments, we analyzed the spatiotemporal characteristics of a laser pulse in the Fourier plane in the 4-f arrangement. Based on these characteristics, we demonstrated two-stage frequency domain optical parametric amplification (FDOPA). The 275-fs signal seed pulse of the 1054-nm central wavelength was amplified in Type I β-BaB2O4 crystals pumped by a 180-ps pulse of 532-nm wavelength 532 nm. Using two-stage FDOPA at pump energy of 27 mJ (1.5 GW/cm2), a total net gain of 67 was obtained, yielding an output energy of 174 μJ while maintaining pulse width. We report the new concept of a two-stage FDOPA with beam magnification inside the 4-f arrangement that avoids damage to the output diffraction grating.