Recent advances for temporal and spectral diagnostics of the LMJ front-end laser facility

In lasers used for inertial confinement fusion (ICF) both temporal and spectral performances have to be controlled with accuracy. As commercial systems do not allow accurate enough measurements, we developed new diagnostics. For spectral measurements, we developed an innovative highly resolving spectrometer. This system allows a 1 GHz resolution measure of spectrum in single-shot operation. For temporal shape measurement, we implemented upgrades and go on with the pre-industrial integration of our previous early design, in an all-in-one box system. This system enables real-time analysis of optical pulse shapes for wavelengths from 300 nm up to 2 μm. Thanks to an innovative optical-electro-optical (OEO) sub-converter, it is also possible to measure electrical pulses, with 60 GHz bandwidth at 500 Gs/s and up to 3 Ts/s sampling rate and more than 8-bit dynamics range. We developed an all fibered system that allows direct measurement of temporal Dynamic Extinction Ration (DER)3 for pulsed laser in single shot operation. This device could be adapted to several wavelengths and allows achieving a measurement up to 60 dB of DER with 1 dB accuracy. In brief, we will give an up-to-date description of some recent development in high precision diagnostics applied to LMJ front-end. (authors)