Few-optical-cycle pulses in the near-IR from a non-collinear optical parametric amplifier

In this paper we show that for periodically poled stoichiometric lithium tantalate (PPSLT) and several other crystals (LiIO₃, KNbO₃, LiNbO₃) the group velocity of the idler in a FF-pumped OPA is higher than that of the signal, allowing for ultrabroadband non-collinear amplification in the near-IR. We present a near-IR NOPA based on PPSLT pumped at 785 nm by an amplified Ti:sapphire laser. The NOPA generates ultrabroad spectra spanning from 1.1 to 1.7 mum; preliminary pulse compression experiments on a limited spectral portion produced nearly transform-limited 16-fs pulses. It is concluded that the near-IR NOPA will find application both in time resolved spectroscopy with extreme resolution and, with suitable energy scaling, in high-field physics.