Personal web page : http://iramis.cea.fr/Pisp/107/fabien.quere.html
Laboratory link : http://iramis.cea.fr/LIDYL/PHI/
Laser technology now makes it possible to generate coherent light pulses with durations down to a few tens of femtosecondes only, with an energy per pulse of up to several Joules. These laser beams are likely to exhibit spatio-temporal coupling, i.e. a spatial dependence of their temporal properties across the beam, which can considerably degrade their performances. Our team has developed over the last few years different techniques to measure the full spatio-temporal structure of such lasers. These advanced measurement techniques have been demonstrated on different lasers, including some for the most powerful systems in operation to date. The objectives of this PhD work will be twofold: 1- to exploit these new advanced techniques to characterize different laser sources, of increasing complexity; 2- to improve these measurement techniques, in particular by reducing the number of required laser shots. This second point will be achieved by both using the modern techniques of compressed sensing, and designing new schemes to encode the relevant information in the measured data. The ultimate goal is to obtain all information on the spatio-temporal structure of the beam in a single laser shot, in contrast to the hundreds of shots required with the present techniques.