13-fs, 1-MW Ti:Sapphire Laser Oscillator in a Long-Cavity Configuration

Abstract

We generated 13-fs pulses with a peak power of 1 MW from a long-cavity femtosecond Ti:sapphire laser with 3.7-W pumping. To boost laser energy without degrading the pulse quality from that of a standard laser cavity of 100 MHz, the cavity length was extended by adding four concave mirrors using an image relay scheme, lowering the repetition rate of the oscillator to 27 MHz. The long-cavity laser operating stably with 120-nm spectral width was suitable for the front-end oscillator of a femtosecond chirped-pulse amplification laser.