Amplitude and phase control of ultrashort pulses by use of an acousto-optic programmable dispersive filter: pulse compression and shaping

Abstract

We demonstrate experimentally that an arbitrary phase and amplitude profile can be applied to an ultrashort pulse by use of an acousto-optic programmable dispersive filter (AOPDF). Our filter has a large group-delay range that extends over 3 ps and a 30% diffraction efficiency over 150 THz. Experiments were conducted on a kilohertz chirped-pulse amplification laser chain capable of generating 30-fs pulses without additional pulse shaping. Compensating for gain narrowing and residual phase errors with an AOPDF in place of the stretcher results in 17-fs transform-limited pulses. Arbitrary shaping of these 17-fs pulses is also demonstrated in both the temporal and the spectral domains.

Excitation and Control of Plasma Wakefields by Multiple Laser Pulses

“…In this first demonstration the pulse spacing within the train was approximately constant since the total available laser pulse energy was low; it would be straightforward to maintain resonant excitation with large amplitude wakefields by controlling the chirp of one or both pulses, for example by an acousto-optic programmable filter [50]. Our results are important since they are the first experimental demonstration of wakefield excitation by a laser pulse structure which is long compared to the plasma period, and which has sufficient control to overcome relativistic saturation; as we have shown, this approach also offers the potential for energy recovery.…”

Optimisation de la génération d'harmoniques d'ordre élevé à l'aide d'une optique adaptative et d'un modulateur acousto-optique

“…Afin de contrôler spectralement les harmoniques et idéalement de pouvoir déplacer une harmonique donnée de 1.5 eV pour obtenir une accordabilité totale des harmoniques, nous avons utilisé un modulateur acousto-optique dispersif programmable (AOPDF) , connu sous le nom de « Dazzler », qui permet simplement et efficacement de modifier la phase spectrale du laser. Ce dispositif est généralement utilisé pour contrôler la phase spectrale et l'amplitude spectrale dans les chaînes lasers [3,4].…”

Asymmetric Pulse Shapes in Grating-Based CPA Compressors and Optimal Electron Acceleration in Plasmas

“…In the experiments, pulse shaping is achieved with a conventional grating compressor scan by intentionally offsetting the higher order phase components. This method of higher order phase control is a simple alternative to the recently developed acousto-optic phase modulation devices such as the DAZZLER [4,15], and can conveniently be used at arbitrarily high power and energy levels limited only by the damage threshold of the compressor gratings.…”