Optical parametric amplification of mid-infrared femtosecond pulses using periodically-poled lithium niobate

Mid-IR femtosecond pulse generation scheme is developed based on optical parametric amplification in periodically-poled lithium niobate with 800-nm Ti:sapphire laser as the pump. We obtained 620-nm bandwidth mid-IR pulses at center wavelength of 3.5 mum. After the compensation of the second-order dispersion, the pulses are compressed down to 42 fs.