Quality anaiysis and correction of aberrations in spatial filters used in high-power laser apparatus

An analysis is made of spherical aberrations produced by a sequence of spatial filters of a kind used in high-power laser systems. A simple method for correcting these aberrations without recourse to aspherical optics is proposed. It is shown that a high-quality beam can be formed at the exit of a laser using a single two-component objective whose own aberrations are equal and opposite in sign to the overall aberrations of the whole system.