Intense femtosecond mid-infrared pulses tunable between 3-20 /spl mu/m

Summary form only given. Femtosecond pulses in the mid-infrared provide a broad potential for condensed matter studies enabling time-resolved investigations for instance of molecular vibrations or inter subband dynamics in semiconductor nanostructures. At wavelengths beyond 10 /spl mu/m, very short pulses of /spl ap/100-200-fs duration were obtained at high repetition rates by parametric mixing within the broad spectra of 13-fs pulses from a 2-MHz cavity-dumped Ti:sapphire oscillator in GaSe. From amplified systems, which intrinsically deliver much higher pulse energies, 130-fs pulses tunable from 3-10 /spl mu/m were generated by difference frequency mixing pulses from an optical parametric amplifier (OPA) in AgGaS/sub 2/, but for longer wavelengths the potential for generating such pulses shorter than 700 fs, has not yet been exploited. We demonstrate a kilohertz source of intense /spl ap/100-fs mid-infrared pulses with a tuning capability beyond 10 /spl mu/m. Near-infrared signal and idler pulses (/spl lambda/= 1-2 /spl mu/m) are generated in a two-pass, type II BBO OPA pumped by 200 /spl mu/J from a l-kHz, 800-nm Ti:sapphire regenerative amplifier.