Generation of broadly tunable sub-30-fs infrared pulses by four-wave optical parametric amplification

We report on the generation of sub-30-fs near-IR light pulses by means of broadband four-wave parametric amplification
in fused silica. This is achieved by frequency downconversion of visible broadband pulses provided by a
commercial blue-pumped beta-barium borate crystal-based noncollinear optical parametric amplifier. The proposed
method produces the IR idler pulses with energy up to ∼20 μJ and tunable in wavelength from 1 to 1.5 μm. The
shortest pulse duration is 17.6 fs, measured at 1.2 μm.