LOA (Palaiseau, France)

LOA has played a pioneering role in the development of ultrafast laser-matter science at high intensities and related new concept of ultrafast lasers and secondary sources (electrons, protons, EUV, X-ray and gamma-rays, THz). LOA was one of the founders of the LASERLAB community. LOA develops cutting-edge advanced programs to answer scientific and societal challenges.
Research highlights

Laboratoire d' Optique Appliquée
CNRS, Palaiseau, France



Contact: Dr Stéphane Sebban
Dr Philippe Zeitoun

Electron acceleration

After more than a decade of electron acceleration on Joule-class laser at LOA, a new breakthrough has been achieved by demonstrating few MeV electron bunch driven by mJ, kHz laser [Plasma Phys. Control. Fusion 61, 014012 (2019)]

Relativistic X-ray emission

We demonstrated a simple method to enhance the energy and the flux of Betatron sources without increasing the laser energy. The orbits of the relativistic electrons emitting the radiation were controlled using density tailored plasmas. [Phys. Rev. X 10, 011061 (2020)]

Soft X-ray laser

Using a ptychographic approach, we were able to reconstruct the complex wavefront of the seeded soft X-ray laser wave. Its shows an excellent agreement with extensive 3D Maxwell-Bloch calculations. The soft X-ray laser was strongly focused on a Ti foil and generated its second harmonic. [Arxiv physics.optics, arXiv:2009.05151]


Lasing in air

A cavity-free laser in the sky could lead to revolutionary improvements in optical remote sensing for atmospheric science. Intense forward emission around 391 or 428 nm with energy up to several microjoules was observed during filamentation of femtosecond laser pulses in atmosphere. [Phys. Rev. Lett. 123, 243203 (2019)]

High NA EUV wavefront sensing

A new EUV wavefront sensor with numerical aperture up to 0.19 has been developed at LOA. It has been successfully tested at FLASH free-electron laser with the alignment of a Schwarzschild microscope as well as internally for measuring the wavefront of harmonics from solid. This is an important step towards EUV sensors dedicated to EUV lithography. [to be published in Sensors 2020]

Projects performed by external users >>

Further application highlights

Lasers and Cancer Lasers and Metrology


The LOA develops ultra-short and intense laser aiming at developing ultrafast laser-matter science at high intensities and related new concepts of secondary sources (electrons, protons, EUV, X-ray and gamma-rays, THz).


The laboratory covers 7 research areas.

  • Production of the shortest duration laser pulses to provide the highest laser intensity with table-top, high repetition-rate laser systems to drive relativistic-intensity laser-plasma and attosecond science.
  • Study of fundamental aspects of laser-plasma interaction in the relativistic regime to develop compact particle accelerators.
  • Generation of ultrafast X-ray sources from laser-produced plasma or laser-driven electron beams.
  • Pulsed radiolysis using ultrafast laser-driven electron or X-ray beams.
  • Non-linear propagation of ultra-short lasers in transparent media like in air.
  • High-resolution imaging taking advantages of the compactness, small source size and short pulse duration of the secondary sources (electron, EUV, X-rays and gamma-rays)
  • Ultrafast solid-state physics and femto-magnetism.
Equipment offered to external users


Our research infrastructures lie in one site located at the ENSTA-Yvette research centre where experimental sites and offices are spread over a total surface of 5200 m2. LOA provides uniqueness instrumentations in the field of ultrafast laser-plasmas with laser duration down to an optical cycle & high repetition-rate, multi-beams synchronized at the femtosecond time-scale (up to 5 in Salle Jaune for example), dedicated topics and fixed experimental set-up.




Peak intensity

rate (Hz)

Experimental area


Salle Jaune

+ probe beams
+ 0.5J / 500 ps beam


≥ 5x1020


3 fully equipped beamlines in radioprotected environment

• Electron acceleration
• Ultrafast relativistic X-rays
• Soft X-ray laser
• Application of secondary sources

Salle Corail

3 mJ




5 fully equipped beamlines

• High harmonic generation
• EUV metrology
• Femtosecond  electron spectroscopy
• Ultrafast solid-state physics
• THz
• Femtomagnetism

Salle Noire

4 mJ

≤ 4



1 versatile experimental chamber

• High harmonics from solid
• Electron acceleration
• Non-linear physics.

Salle Violette

15 mJ




1 versatile site

• Lasing in air
• THz
• Laser-driven acoustic wave
• Electrical discharge triggered by laser