Application of Cavity Deformable Mirror in PW Facility with U-Turn Reverser

For beam passing through cavity mirror twice in multi-pass amplifier laser facility, deformable mirror is often applied at location of cavity mirror for the goal of improving correction range. However, multi-pass amplifier with U-turn for improving optical quality has its own feature different from other facilities. Beam has 90° rotation and size change between 1~2 pass and 3~4 pass propagation. A new mathematical method is described to prove the solution existence of cavity deformable mirror and the application of cavity deformable mirror is verified in XG-PW facility with U-turn reverser. The results are important for the adaptive optics system design of succeeding large-scale laser facility.