Generation of high-power femtosecond pulses near 1.5 μm using acolor-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 μm. 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 μm. The amplified pulses are used to generate a continuum in various solid media without optical damage. The continuum generated in BaF₂ is extremely broad, extending from below 400 nm to 3.5 μm. Construction and operating details are discussed as well as the system's utility for femtosecond measurements in the infrared and high-power experiments