Pulse Compression by Filamentation and an Adaptive Pulse Compressor

The compression of ultrashort laser pulses by filamentation in a noble gas is an easy and efficient method to approach the one cycle limit for laser pulses. Up to now pulse compression by spectral broadening is mostly achieved in gas filled hollow fibers. Using Filamentation instead eliminates several drawbacks encountered in use with hollow fibers. In the presentation the different linear and non-linear effects that take place inside the filament are discussed. Such created ultrashort laser pulses can be used afterwards to produce single attosecond pulses through high harmonic generation. Applied in pump-probe experiments attosecond light pulses yield a higher time resolution. The presented setup for filamentation is based on previous works [1] and was improved in several details. During the experiments with different parameters a major dependency on repetition rate of the laser pulses was discovered. Until now this phenomenon has not been published in literature and it could pose a limitation to the use of filamentation in combination with high repetition rates. On the short time scales of few cycle laser pulses it is of particular importance to have good means of compensating dispersion, which is introduced by air and optical material. In our case the remaining dispersion is compensated by a multi level setup. This setup consists of a chirped mirror pair and a deformable mirror. Using the combination of those different parts we are able to flexibly react to changing configurations and variation of experimental parameters while ensuring optimal compression. Further the setup can be used in combination with a ZAP-SPIDER and for pulse shaping