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.