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 ${\text{cm}}^{-1}$ 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 ${\text{BaB}}_2{\text{O}}_4$ (BBO) crystals is pumped by $20\text{-}\text{ps}$ pulses of the second harmonic of an Nd : YAG laser. For a superluminescent diode spectral width of $275{\text{cm}}^{-1}$ (centre wavelength $790\text{nm}$), the spectral width of picosecond pulses at the parametric amplifier output is $203{\text{cm}}^{-1}$. At a total pump energy of $7.2\text{mJ}$ for BBO crystals, the energy of the enhanced emission of the superluminescent diode is found to be $0.6\text{mJ}$.