Design and characterization of a 300-TW Ti:sapphire laser

A Ti:sapphire laser system referred to as SILEX-I with the chirped pulse amplification technology has been built at CAEP which consists of three stages operating at 5TW, 30TW, and 300TW, each having a compressor and target chamber to meet different needs from diverse applications. The first and the second stages work at 10Hz, while the third at single shot. Pulse durations of 26fs have been obtained by installing an acousto-optic programmable dispersive filter (AOPDF) before the stretcher to compensate for the spectral gain narrowing in the regen. By taking a number of advanced measures for spatial beam control, such as spatial beam-shaping, relay-imaged propagation, precise alignment of compressor gratings and OAP, near-diffraction limited focal spots (FWHM) have been obtained. Focused intensities are measured in the range of (1-5) x 1020W/cm2 with an f/2.2 OAP. The laser system will be able to operate at 500TW and even higher soon. The SILEX-I has been operated for experiments since its completion early in 2004, covering electron and proton acceleration, hot electron production, transport and deposition, neutron production, x-ray radiation, femtosecond laser pulse propagation in air, warm matter, and other strong-field studies. The laser system has shown an excellent stability and reliability and has been the most powerful femtosecond Ti:sapphire laser facility to operate for experiments in recent years.