Compression of terawatt-level pulses in the air

Summary form only given. The increasing peak power of CPA laser chains based on the chirped pulse amplification leads to the use of a compressor or a part of the compressor under vacuum in order to avoid the nonlinear effect when the pulse has been fully recompressed. We propose to replace the compressor under vacuum by a compressor in the air combined with a set of chirped mirrors that is under vacuum. The "air-compressor" will be aligned such that the residual spectral phase after the chirped mirror\´s set will be minimized in order to obtain the optimal pulse duration. This scheme allows the pulse duration to be in the range of 1 ps at the exit of the grating compressor.