Key words
Optics – Photonics – Laser – Generation of ultra short laser pulses – Light-matter interaction – Laser machining and laser material processing – Signals and Systems – Holography.
Optics, Lasers, Holography and Optical metrology
I started my research activities with holography, a principle discovered in 1948 by Denis Gabor, to record the phase and intensity of a wave field. Michel Grosmann, Professor at Strasbourg university, a passionate holographer and optical physicist, introduced me to this fascinating topic and helped me to convert my russian master of physics into a french PhD in Optics. My first attempts was to apply the technique to non destructive characterization of materials and structures. Later on, I got involved in the development of new recording materials, techniques to increase the speed of information processing and use of holography for storage of information.
Ultra short laser pulses : generation, characterization and applications
In 1977, during my first trip to United States, I met with a great laser physicist, the Professor Jean-Claude Diels. This was the beginning of a life long collaboration during witch I discovered the most fascinating and rewarding aspects of research activity. I was involved during a decade (from 1978 to 1988) in the run for obtaining shorter and shorter laser pulses. Our group was the first to introduce the compression technique based on dispersion control. We showed that pulses as short as 50 femtoseconds could be obtained using this technique. The technology has made significant progresses ; however the basic principles used for generation and characterisation of the ultrashort pulses have remained the same. Ultra short pulses are used in many areas. One of them is the microprocessing of materials, for which the Irepa laser has become a center of competence. Ultrashort laser pulses are also used for distance measurement ; the IPP team of Icube has made significant achievement due the work of P. Pfeiffer.
Power photonics – laser material machining and processing
Power photonics encompasses the generation, shaping and use of high intensity laser beams. Research in this area is well suited to an engineering school as the National Institute of Applied Physics. To make the activities even closer to industry, we have created a intermediate structure called Irepa laser on the model of Fraunhofer Institute in Germany. We have started with laser-mater interaction applied to metal cutting. Olivier Frenaux, a mechanical engineer from the school started the project with a high power CO2 laser. To-day Irepa Laser employs more than 30 people involved in laser process development in relation with industries and research institutions. Many of our projects in power photonics were made in collaboration with Irepa. Our present research team continuously works in close collaboration with this laser center.
The study of laser-material interaction took me naturally to the development of methods and tools for the conception, characterization and implementation of systems for wave fields imaging and processing, diffractive components, wave guides.