  All space-time coupling effects arising in an asymmetric optical compressor
[1] consisting of two non-identical pairs of diffraction gratings are described
analytically. In each pair, the gratings are identical and parallel to each
other, whereas the distance between the gratings, the groove density, and the
angle of incidence are different in different pairs. It is shown that the
compressor asymmetry does not affect the far field fluence and on-axis focal
intensity. The main distinctive feature of the asymmetric compressor is spatial
noise lagging behind or overtaking the main pulse in proportion to the
transverse wave vector. This results in a degraded contrast but reduces beam
fluence fluctuations at the compressor output. Exact expressions are obtained
for the spectrum of fluence fluctuations and fluence rms that depends only on
one parameter characterizing compressor asymmetry. The efficiency of
small-scale self-focusing suppression at subsequent pulse post-compression is
estimated.
