Confocal feedback systems can perform analog optical solutions of two-dimensional integral equations. Methods for solution of Fredholm equations by space-variant feedback and of Volterra equations using multiple feedback have been found and experimental results obtained. Two-dimensional problems of this type are difficult and time consuming to solve digitally, but the optical solution is obtained at high speed.
© 1981 Optical Society of America
Jack Cederquist, "Integral-equation solution using coherent optical feedback," J. Opt. Soc. Am. 71, 651-655 (1981)