Two-optical-cycle pulses in the mid-infrared from an optical parametric amplifier

Ultrabroadband mid IR pulses with energy as high as 2 mu J and tunability from 2 to 5 mu m are generated as the idler beam of an 800 nm pumped optical parametric amplifier in periodically poled stoichiometric lithium tantalate. After bulk compression in a Ge plate and frequency-resolved-opticle-gating characterization, a pulse duration as low as 25 fs was measured, corresponding to two optical cycles of the 3.6 mu m carrier wavelength. (C) 2008 Optical Society of America