Laboratoire d'Optique Appliquée ~ LOA, Palaiseau, France

Le nouveau laser 200 TW arrive au LOA - April 3, 2012 - The new femtosecond intense Laser system (power of 200 TW ) developped by Amplitude Technology within the project SAPHIR has arrived at LOA. The objectives of this project is to achieve ions acceleration for protontherapy. It brings together several academic laboratories working on the physics of laser-matter interaction, medical institutions as well as companies in the field of optical and laser technologies. The LOA is setting up the experimental system in one of its laboratory sites. First shots on target are expected by summer 2012.Upgrade of the Salle Jaune LaserAfter more than ten years of intensive use with very prolific scientific achievements including many breakthroughs such as electron acceleration by lasers, ultrafast X-ray betatron, Compton, Thomson sources or the seeded OFI plasma X-ray laser, the most intense LOA femtosecond laser (30 fs, 50 TW, 1.5 J) is currently under major upgrade. The infrastructure is significantly improved with larger laser and users environments. The upgraded "Salle Jaune" laser will deliver an energy of 4-5 Joules, a peak power of 120 TW at 2 Hz, which can be divided into two beams of equal energy, fully synchronized with several lower energy beams of durations from 30 fs to nanoseconds. This intense light source will be accompanied by three independent and radio-protected experimental areas. First experiments are scheduled for fall 2012. Ultrafast gamma-ray source- March 17, 2012 - Researchers from the FLEX and SPL teams at LOA have just demonstrated (accepted for publication) a new method based on laser-matter interaction to produce beams of energetic X-ray radiation with unique properties. The physical process used here is called inverse Compton scattering, during which a beam of energetic electrons collides with a laser. Using a fully all-optical technique, LOA researchers successfully produced flashes of gamma-ray radiation more than 10,000 times brighter than those produced by existing conventional sources. Compact, simple and efficient, the scheme is only based on the interaction between an intense femtosecond laser and a helium gas jet.Nature Physics, Attosecond control of plasmasFebruary 20th, 2012 - Today, light fields of controlled and measured waveform can be used to guide electron motion in atoms and molecules with attosecond precision. An LOA team, in collaboration with teams from LULI and CEA Saclay has demonstrated attosecond control of collective electron motion in plasmas driven by the extreme intensity (≈ 1018 W/cm2) light fields generated at LOA (Nature Physics, published online 25 march 2012). They focused controlled few-cycle laser pulses of the last generation LOA laser at the interface between vacuum and a solid-density plasma, where the intense laser field launches and guides sub-light-cycle motion of plasma electrons electrons with characteristic kinetic energies in the multi-kiloelectronvolt range - two orders of magnitude more than what has been achieved so far in atoms and molecules. Basic spectroscopy of the coherent extreme ultraviolet radiation emerging from the laser-plasma interaction allowed the researchers to probe this collective motion of charge with sub-100-attosecond resolution. This is an important step towards attosecond control of electronic processes in laser-driven plasma experiments.

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Le Laboratoire d'Optique Appliquée (LOA) is an UMR (Unité Mixte de Recherches) ENSTA-Paris Tech - CNRS - École Polytechnique. Its research activity covers a broad spectrum of science in the field of ultrafast lasers and their applications: development of intense laser sources, laser-matter interaction and plasma physics, production of compact sources of energetic radiations and particles, multidisciplinary applications of these sources. Read more

News of the month

Two scientific results of the Laboratoire d'Optique Appliqée (LOA) are highlighted in the May 2012 covers of Nature Physics and Nature Photonics. These two results on the attosecond control of plasma and on the generation of all-optical gamma-ray beam by Compton scattering, were obtained by three teams of the laboratory, FLEX (X-ray source development and application), SPL (Particle source development and application) and PCO (Physics of... read more | Read more news

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