US Patent 4,965,760
United States Patent and Trademark Office
University of Iowa Research Foundation (Iowa City, IA, US)
Experimental studies of a nonlinear interface have indicated that saturation of the nonlinear refractive index may play a critical role in controlling the transition from total internal reflection to nearly total transmission. Numerical simulations of the behavior of a saturated nonlinear interface confirm that saturation effects can dramatically improve transmitted beam shape and switching quality.
Cuykendall, Robert R. and Strobl, Karlheinz Saturated optical interaction gate. US Patent 4,965,760 filed April 21, 1989 and issued October 23, 1990. https://ir.uiowa.edu/patents/77