Abstract
Temporal contrast degradation due to mid-spatial-frequency error in
chirped-pulse amplification stretcher optics is studied. Third-order
cross-correlation measurements reveal a temporal peak that appears
when using two different mirrors processed by magnetorheological
finishing, despite an improvement in rms roughness compared to a third
unprocessed mirror. Simulations based on measured power spectral
density show how the actual impact on contrast is different from
measurements using a typical bandwidth-limited third-order cross
correlator. Strategies are proposed to avoid this type of contrast
degradation while exploiting computer numerically controlled polishing
techniques for enhancement of surface figure and roughness.
Funder
National Nuclear Security
Administration
National Science Foundation
New York State Energy Research and
Development Authority