A simple four-pass Ti:sapphire amplifier is seeded by sub-10-fs pulses generated from a mirror-dispersion-controlled Ti:sapphire laser. Pulses of 17-18-fs duration with energies up to 50 and 100 microJ have been produced at repetition rates of 2 and 1 kHz, respectively. Because of the absence of a pulse stretcher, this performance is achieved from an extremely compact system.
