High repetition rate (100 Hz), high peak power, high contrast femtosecond laser chain

Abstract

Conference on Solid State Lasers XXV - Technology and Devices, San Francisco, CA, FEB 15-18, 2016International audienceHigh intensity femtosecond laser are now routinely used to produce energetic particles and photons via interaction with solid targets. However, the relatively low conversion efficiency of such processes requires the use of high repetition rate laser to increase the average power of the laser-induced secondary source. Furthermore, for high intensity laser-matter interaction, a high temporal contrast is of primary importance as the presence of a ns ASE pedestal (Amplified Spontaneous Emission) and/or various prepulses may significantly affect the governing interaction processes by creating a pre-plasma on the target surface. We present the characterization of a laser chain based on Ti:Sa technology and CPA technique, which presents unique laser characteristics : a high repetition rate (100 Hz), a high peak power (> 5 TW) and a high contrast ratio (ASE<10(-10)) obtained thanks to a specific design with 3 saturable absorbers inserted in the amplification chain. A deformable mirror placed before the focusing parabolic mirror should allow us to focus the beam almost at the limit of diffraction. In these conditions, peak intensity above 1019W. cm(-2) on target could be achieved at 100 Hz, allowing the study of relativistic optics at a high repetition rate

Impact of the pulse contrast ratio on molybdenum Kα generation by ultrahigh intensity femtosecond laser solid interaction

“…Experiments were performed at ASUR facility in LP3 laboratory 41 , 42 . The 20 TW line (Amplitude Technologies) based on Ti:Sa technology and chirped pulse amplification technique delivers an output beam at 800 nm with super-Gaussian spatial profile and energy up to 300 mJ on target with rms energy stability of ~2.5% at 10 Hz repetition rate.…”