Paul M. W. French

Generation of pulses as short as 93 fs from self-starting femtosecond Cr:LiSrAlF(6) lasers by exploiting multiple-quantum-well absorbers.

A Cr:LiSrAIF(6) laser has been mode locked by using a multiple-quantum-well (MQW) absorber. With the MQW absorber inside the laser cavity, Kerr lens mode locking is initiated, yielding transform-limited pulses as short as 93 fs. Pulses of 500-fs duration have also been produced by using resonant passive mode locking with the MQW absorber in an external cavity.

Tunable group velocity dispersion interferometer for intracavity and extracavity applications

Abstract Recent developments in femtosecond laser technology have demostrated the importance of controlling both intracavity and extracavity group velocity dispersion. We have investigated the potential of the Gires-Tournois interferometer as a means of providing adjustable group velocity dispersion, both intracavity and extracavity, in a configuration which is of low insertion loss, compact, highly tunable and insensitive to wavelength or polarisation.

Argon-ion-pumped and diode-pumped all-solid-state femtosecond Cr:LiSrAlF(6) regenerative amplifiers.

A tunable femtosecond solid-state amplifier system that uses only 3 W of 488-nm argon-ion pump power has been demonstrated to deliver microjoule pulses at repetition rates up to 20 kHz, with a maximum pulse energy of 14 mu;J obtained at 5 kHz. An all-solid-state, tunable, diode-pumped Cr:LiSrAlF(6) regenerative amplifier has been demonstrated, for the first time to our knowledge, that amplifies femtosecond pulses to energies exceeding 1 mu;mJ at up to a 16-kHz repetition rate.

Diode-pumped spatially dispersed broadband Cr:LiSGAF and Cr:LiSAF c.w. laser sources applied to short-coherence photorefractive holography

Abstract We demonstrate a novel high power broadband laser source for low coherence interferometry that is based on a simple three mirror diode-pumped c.w. Cr 3+ laser. The cavity design utilises a single intracavity prism to spatially disperse the oscillating laser mode within the pumped region of the laser crystal in order to counteract spectral gain narrowing. We demonstrate continuous wave spatially coherent output beams with spectral widths as wide as 37 nm, which are tunable across the gain linewidth of the laser. Using a single 100 μm stripe width 670 nm diode pump laser we obtained output powers up to 105 mW for incident pump powers of 410 mW. We demonstrate the application of this source (adjusted for a 13 nm bandwidth output) to 3-D imaging through a diffuse medium using photorefractive holography.