The recent progresses in lasers with ultra-high-intensity pulses are now hindered by a strong limiting factor linked to imperfections in the pulse temporal profile. Innovative physics experiments at relativistic intensities that probe new domains such as particle acceleration or laser assisted nuclear physics are inaccessible due to the high level of amplified spontaneous Emission (ASE) pedestals and pre-pulses. The objectives of this program are to develop new techniques devoted to obtain temporal contrast suitable with interaction in a regime of intensity higher than 1020 W/cm2. Reduction of the ASE level with respect to the femtosecond pulse will be obtained by non-linear effects.
Different ways will be investigated through this RTD program, corresponding with associated work packages: Moreover measurement techniques over high dynamic range will be improved. Non linear cleaning and filtering processes like non-linear cleaning by saturable absorber or non linear interferometer, second harmonic generation, or plasma mirrors will be studied. OPCPA techniques need to be fully characterized in term of contrast improvement, such as excimer amplification usable after seeding by frequency converted pulses. In the first 12 months of the project, partners have successfully designed, bought, built, and implemented: · New high order cross-correlators and UV correlators improving the measurement dynamics. (WP1 tasks 1.1, 1.3, 1.4) · New high energy, high contrast oscillators (WP2 task 2.1) · New schemes of non linear filtering at millijoule level (WP2 task 2.3) · Promising technique using plasma mirrors (WP2 task 2.4) · New designs of excimer amplification in XeF (WP3 task 3.1) · Measurements of ASE contrast properties in Optical Parametric Chirped Pulses Amplification process (OPCPA) (WP4 task 4.2).
Funding SchemeCSC - Cost-sharing contracts
OX11 0QX Didcot,harwell,chilton
221 00 Lund
73130 Chania - Crete