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DOE OSTI · 2376156

Temporal contrast degradation from mid-spatial-frequency surface error on stretcher mirrors

Webb, B.·Dorrer, C.·Bahk, S. -W.·Jeon, C.·Roides, R. G.·Bromage, J.
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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. Furthermore, strategies are proposed to avoid this type of contrast degradation while exploiting computer numerically controlled polishing techniques for enhancement of surface figure and roughness.

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Webb, B., Dorrer, C., Bahk, S. -W., Jeon, C., Roides, R. G., Bromage, J.. 2024-06-04. Temporal contrast degradation from mid-spatial-frequency surface error on stretcher mirrors. https://doi.org/10.1364/ao.522892

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