Plasmaphysik Seminar

Temporal laser contrast

by Dr. Victor A. Schanz (GSI, Darmstadt)

Tuesday, July 16, 2019 from to (Europe/Berlin)
at GSI Darmstadt ( SB3 3.170a )
For many laser-plasma experiments the temporal contrast is of great significance. To be able to measure the contrast is as important as it is to be able to control the laser pulse intensity prior to the main peak. Some  progress has been made over the last couple of years, for example in controlling the level of amplified spontaneous emission. But yet, the understanding and improvement of the temporal pulse profile remains challenging.
We present comprehensive theoretical and experimental studies on the topic of temporal laser pulse contrast in the nanosecond and picosecond time domain.
We show state of the art contrast measurements, provided with a novel "EICHEL"-type cross-correlator. This device enables us to measure the temporal contrast within a dynamic range of more than 13 orders of magnitudes. 
The topic of pre-pulse contrast is discussed and methods for the removal of pre-pulses are presented. Furthermore the temporal pulse profile and contrast degeneration on the picosecond time scale is investigated. We conducted simulations to identify the influence of several distortion effects within a CPA-stretcher onto the temporal pulse profile. Those simulations are compared to measurements and possible solutions for future highest contrast laser systems are suggested.