Ultraintense laser amplification and diagnostic techniques (ilil-pw)
Laser-matter interaction at extreme intensities (>10E20 W/cm2) requires high power, ultrashort (≈30 fs) laser pulses with controlled spatial and temporal quality. In the framework of the ELI-Italy programme, we are upgrading our laser system to the sub-PW power to reach intensities on target in excess of 10E210W/cm2. A new power amplifier is being built to amplify the existing 10 TW laser pulse, while improving the temporal contrast and the focal spot quality. In view of this, a range of measurement and control techniques are being developed and implemented. Laser pulse duration and temporal contrast are currently measured using off-line multi-shot auto-correlator and third-order cross-correlator. However, current interaction experiments often require on-line measurement of pulse duration and contrast to monitor shot to shot fluctuations. We are therefore developing novel techniques to accomplish this complex task. As for the focal spot quality, we are implementing on-line transverse phase measurement and adaptive optics technology to measure and correct phase front distortions of the laser pulse to obtain the best possible focal spot quality with the highest Strehl ratio.