Generation of broadband near-infrared (2–2.5 $\mu$m) radiation from an optical parametric amplifier driven by a Cr:forsterite laser near dispersion anomalies of tuning curves

Pulses with a spectral width of 450 nm at a wavelength of 2.2 $\mu$m are generated in a parametric amplifier based on a type-I BBO crystal pumped by the second harmonic (620 nm) of a Cr:forsterite laser. Such a broadband radiation is obtained in a specific regime of the group velocity matching near the vertical region of the tuning curve. The generated pulses can be compressed to a duration of about 2.5 optical cycles (34 fs) in a medium with positive group-velocity dispersion.