Parametric amplification of broadband radiation of a cw superluminescent diode under picosecond pumping

It is proposed to use cw superluminescent diodes with a spectral width of about 300 cm^-1 and high spatial coherence as seed radiation sources in parametric amplifiers with picosecond pumping in order to form broadband picosecond pulses. A two-cascade parametric amplifier based on BaB₂O₄ (BBO) crystals is pumped by 20-ps pulses of the second harmonic of an Nd : YAG laser. For a superluminescent diode spectral width of 275 cm^-1 (centre wavelength 790 nm), the spectral width of picosecond pulses at the parametric amplifier output is 203 cm^-1. At a total pump energy of 7.2 mJ for BBO crystals, the energy of the enhanced emission of the superluminescent diode is found to be 0.6 mJ.