We experimentally demonstrate large, widely tuneable gain using Kerr instability amplification in MgO. By pumping the crystal near optical damage at 1.4 1013 W/cm2 by a femtosecond Ti:Sapphire laser, we amplify visible and near infrared pulses by factors > 5000, or a gain g 17/mm. We temporally characterize the pulses to show that they are 42 fs in duration, much shorter than the pump pulse. In the non-collinear setup, the angle between the pump and seed selects the amplified wavelength, where we find certain angles amplify both the visible and near infrared simultaneously. We find that near the maximum pumping intensities, higher order nonlinearities may play a role in the amplification process.
ARACHCHIGE, CHATHURANGANI JAYALATH; Stephen, Jacob A.; and Hammond, T J.. (2021). Amplification of femtosecond pulses based on c(3) nonlinear susceptibility in MgO. Optics Letters.