Nonlinear holographic gratings developed for high energy laser systems have led to new possibilities in large, lightweight primary mirror designs. The beam sampling technique has made the concept of local loop adaptive optics correction much more attractive because all optical distortions including those in the primary mirror can be corrected.
John M. Fitts, John M. Fitts,
"Nonlinear Holographic Gratings For High Energy Laser Beam Sampling", Proc. SPIE 0171, Optical Components: Manufacture and Evaluation, (4 April 1979); doi: 10.1117/12.957056; https://doi.org/10.1117/12.957056