Laboratoire d’Optique Appliquée, Palaiseau, France
The Laboratory of Applied Optics (LOA) has developed intense femtosecond lasers for many years. LOA has been a pioneer in the use of amplification modules based on titanium-sapphire crystals. Since about 20 years these lasers have become the standard technology to deliver femtosecond pulses of high peak intensity.
Thanks to significant developments made by the LOA in the years 80-90, it was possible to produce in 1995 laser pulses reaching 30 fs in duration at an energy level of several joules. It was an important increase in intensity by several orders of magnitude compared to existing lasers. This was also the starting point of entirely new issues at LOA, all related to laser-plasma interaction.
Since the late 90s and early 2000s, laboratory teams were the main authors of remarkable scientific breakthroughs published in journals of the highest impact factor. LOA has played a leading role for activities related to ultrafast science, especially on the production of sources of radiation and particles.
These sources offer unique properties: ultrashort duration, intensity, energy, compactness. It opens new fields of scientific research in interdisciplinary areas at both the academic and societal levels or for defense.
As examples: spatial&time observation with high resolution of the matter (structure, atoms, electrons, nuclei with time ultrabref: 10-12 to 10-18 seconds), new techniques of radiotherapy and protontherapy by laser, eye surgery with femtosecond laser, wireless transfer of high current, compact accelerators of energetic particles, electromagnetic vulnerability.
Pump-probe experiments can be done with femtosecond synchronization of particles and radiations simultaneously like a proton beam for the excitation and the probing by a beam of ultrafast X-ray.
The study of plasma for thermonuclear fusion, the creation and characterization of new states of matter, the observation and control of ultrafast transient structures of matter to develop high-temperature supraconductors or tomorrow's drugs, and the possibility to access to high-energy physics using intense lasers are a few examples of applications that LOA teams are pursuing.