Franck Falcoz

High-efficiency, simple setup for pulse cleaning at the millijoule level by nonlinear induced birefringence.

Nonlinear elliptical polarization rotation is used to improve the contrast of femtosecond pulses by several orders of magnitude. Using nonlinear induced birefringence in air, we produced cleaned pulses with an energy of a few hundreds of microjoules. This technique presents several major advantages, such as convenience and stability of the setup. We investigated the phase profile required for obtaining high-energy pulses. No phase distortion is observed, and the spatial quality of the beam is preserved.

Theoretical and experimental investigations of small-signal gain for a diode-pumped Q-switched Cr:LiSAF laser

We present a theoretical model proving that up-conversion and thermal quenching of fluorescence strongly limit small-signal gain in a CW pumped Cr:LiSAF laser. We have a good agreement with experimental measurements of small-signal gain obtained with a new simple method. We have then optimized the gain in a Cr:LiSAF laser pumped by two 400-mW red diodes. The highest gain, 1.11 at 600 mW of absorbed pump power, is obtained if the pump spot is circularized inside the crystal and if the Cr:LiSAF is pumped on both sides. In Q-switched operation, this laser produces tunable pulses (up to 6.5 /spl mu/J at 10 kHz) between 800 and 900 nm.

All-solid-state continuous-wave tunable blue-light source by intracavity doubling of a diode-pumped Cr:LiSAF laser.

We describe a diode-pumped cw Cr(3+):LiSrAlF(6) laser that produces 190-mW cw output at 860 nm. By frequency doubling in a KNbO(3) crystal we generate 13 mW of second-harmonic light tunable from 427 to 443 nm.

Self-starting self mode-locked femtosecond diode pumped Cr:LiSAF laser

We describe a diode-pumped Kerr-lens mode-locked Cr(3+):LiSrAlF(6) laser that produces 50 mW of 70-fs pulses in the 820-890-nm range when pumped by two red diodes of 400 mW each. By using a lower-transmission output coupler we have demonstrated for the first time to our knowledge a self-starting regime with an output power of 10 mW and 55-fs pulses.

Efficient versatile-repetition-rate picosecond source for material processing applications

We report on the development of an efficient and simple picosecond diode-pumped solid-state laser source with a versatile repetition rate (typically 1 Hz-1 MHz) for material processing applications. The laser source is based on a 4 MHz repetition rate mode-locked oscillator and a passive 3D multipass amplifier both based on Nd:YVO(4) crystals. Micromachining experiments were performed to study the influence of pulse energy on the machining quality for Al, Cu, paper, and glass.

Degradation of picosecond temporal contrast of Ti:sapphire lasers with coherent pedestals

Recompressed pulses from Ti:sapphire chirped-pulse lasers are accompanied by a slowly decaying post-pulse pedestal that is coherent with the main pulse. The pedestal typically consists of numerous pulses with temporal separation in the picosecond range. The source of this artifact lies in the Ti:sapphire active medium itself, both in the Kerr-lens mode-locked oscillator and in subsequent amplifiers. In the presence of substantial self-phase modulation, after recompression the post-pedestal generates a mirror-symmetric pre-pulse pedestal. This pedestal severely degrades the leading edge of the output pulse. This degradation is far more limiting than the original post-pedestal and severely lowers the achievable temporal contrast.

Towards High Repetition Rate Ultra-Intense Lasers, Latest Developments at Amplitude Technologies

We report the latest developments on the ELI-ALPS project dedicated to attosecond science with light sources delivering ultrashort pulses between THz and X-ray frequency range at high repetition rate.

Towards high energy 10 fs laser pulse via regenerative pulse shaping

We demonstrated the use of regenerative pulse shaping approach to obtain ultrashort pulses with at the output of titanium: sapphire laser system. This scheme can be scaled to higher output energy and sub 10fs pulses.

Efficient versatile-repetition-ate ps source for material processing applications

We report on the development of an efficient and simple picosecond diode-pumped solid-state laser source with versatile repetition rate (typically 1Hz-1 MHz) for material processing applications.

Efficient Diode-Pumped LiSAF Laser in Continuous Wave and Actively Mode-Locked Regime

A Cr3+:LiSrAlF6 laser pumped by a 500 mW red diode laser has produced 60 mW cw at 850 nm and pulses of 34 ps at 870 nm in actively mode-locking with a tunability of 60 nm.