My research focuses on the production of high-energy photons and particles based on the interaction of an intense laser pulse and a plasma. I got my PhD in 2013, in the frame of a European collaboration, on the first experiments performed with a coherent Free Electron Laser (FEL) in the X-UV spectral range. I then joined the LOA laboratory of Ecole Polytechnique in France where, during 10 years, I worked on new concepts of femtosecond sources from the THz to the X-ray domain, relying on processes such as high-order harmonic generation in rare gases, laser filamentation or laser-wakefield acceleration. Being at CEA since 2023, I am developing experiments aiming at producing powerful beams of relativistic particles and X/gamma rays (betatron, Compton, Bremsstrahlung), and eventually using them to probe ultrafast dynamics in matter under extreme conditions. This is achieved within pump-prope schemes that can be set up on different kinds of experimental platforms, ranging from high-repetition rate sources with moderate energy to the highly energetic LaserMégaJoule installation, with the PETAL petawatt laser pulse.