Chirped amplification of 50-fs 100-uJ pulse at the repetition rate of 5 kHz

This paper presents a Ti-sapphire-based laser amplification system in which the technique of a chirped- pulse- amplification is used. It consists of a laser oscillator, a pulse stretcher, a regenerative amplifier and a pulse compressor. The laser oscillator is a home-made self-mode- locked Ti-sapphire (3 mm long) oscillator. The oscillator pumped by 5 W of cw all line Argon laser can generate Fourier-transform-limited sub-20 fs duration pulses at a 91 MHZ repetition rate, a center wavelength of 800 nm, a FWHM bandwidth of a spectrum of 80 nm. The seed pulses from the oscillator are stretched by a factor of 1000 with a four- pass grating stretcher at first. After stretching, these pulses are seeded into a Ti-sapphire regenerative amplifier pumped by a frequency-doubled Q-switched a Nd:YAG laser at 5 KHZ. We have obtained single-pulse energy of 100 (mu) J, pulse duration of 50 fs at the repetition rate of 5 KHZ.