Generation and compression of an intense infrared white light continuum in YAG irradiated by picosecond pulses

An intense white light (WL) continuum from 1600 to 2400 nm is generated in a 20-mm-long YAG irradiated by 1-ps, 1030-nm pulses. Long filamentation formed in the YAG is proven to be responsible for the enhancement of the longer-wavelength spectral part of the WL. The WL is compressed down to 24.6 fs ( 3.9 cycles at 1900 nm) after optical parametric chirped-pulse amplification in a lithium niobate crystal near degeneracy, confirming that its spectral phase is well behaved. The pulse compression experiment reveals that the group delay introduced in the WL generation process is dominated by the dispersion of YAG.