HE-Arc engineering students had to face real issues encountered by a company.
Radio waves, microwave ovens and mobile phones, infra-red waves from TV remote controls; these invisible beams are part of our daily life. They have one thing in common: they belong to the vast family of electromagnetic waves. The laser developed by Clément Paradis emits infra-red waves that are therefore invisible to the naked eye.
My work led to the production of an oscillator that emits an infra-red laser beam with a record level of average power for this type of laser, explains Clément Paradis. With a mean output power of over 10W and pulses of 90 fs, the laser delivers more than twice as much power as other comparable oscillators.
But its main characteristic is linked to the adjective “ultra-fast”: it emits sequences of pulses of some tens of femtoseconds in duration (1 fs = 10-15 s). This type of laser generates powerful waves that are especially interesting because they can be converted into other frequency ranges aside from infra-red, such as extreme ultra-violet or terahertz. At these different frequencies, many molecules have a very distinct and recognisable signature. Thus this laser is an ideal tool to explore the interactions of matter, such as between water (H2O) and other compounds. In using these ultra-short pulses, it will be possible to analyse extremely fast chemical processes, such as how water molecules act as a solvent in medicines.
It is the same effect as strobe lighting,” Thomas Südmeyer clarifies. “Through a series of images, the ultra-fast pulses reveal the dynamic of the links between atoms and molecules. Information that is inaccessible to us at present