G. Sucha

Generation of high-power femtosecond pulses near 1.5 mu m using a color-center laser system

The authors have developed a high-power F-center laser system capable of generating femtosecond pulses with energies exceeding 50 pJ at wavelengths near 1.5 mu m. Short pulses (140 fs) from an additive-pulse mode-locked NaCl laser are amplified in a multipass NaCl amplifier at kilohertz repetition rates. The system can generate peak powers approaching 500 MW, with wavelengths tunable from 1.52 to 1.64 mu m. The amplified pulses are used to generate a continuum in various solid media without optical damage. The continuum generated in BaF/sub 2/ is extremely broad, extending from below 400 nm to 3.5 mu m. Construction and operating details are discussed as well as the systems utility for femtosecond measurements in the infrared and high-power experiments. >

Spatio-temporal nonlinear dynamics in a mode-locked Ti:sapphire laser

We present results of a study of nonlinear dynamics in a cw-pumped, Kerr-lens mode-locked (KLM) laser with gain aperturing. Previous to this work, the only measurements of nonlinear dynamics in ultrafast laser systems have been performed in additive pulse modelocked (APM) systems. These revealed a variety of interesting dynamics, however the APMs reliance on interferometric stability severely limited comparison between theory and experiment. In contrast, KLM mode-locking in Ti:sapphire is extremely robust. This has allowed us to perform the first, to our knowledge, detailed measurements of nonlinear dynamics in any femtosecond laser system. We have observed period two, period three, and higher quasi-periodic dynamics in the laser pulse trains, and studied these dynamics as functions of cavity configuration, nonlinearity, and dispersion.