A confocal Fabry-Perot interferometer is used to produce feedback within an optical processor. The resulting confocal feedback system (CFS) has a complex-valued feedback transfer function and performs analog solution of partial differential equations (PDE’s). The CFS is interfaced to a microcomputer via a laser scanner and video electronics to create a hybrid processor, thus taking a major step toward the practical use of the CFS for the high-speed solution of PDE’s. Solutions to the three types of second-order linear PDE’s in two dimensions—elliptic, hyperbolic, and parabolic—were obtained experimentally and analyzed.
© 1980 Optical Society of America
Jack Cederquist and Sing H. Lee, "Coherent optical feedback for the analog solution of partial differential equations," J. Opt. Soc. Am. 70, 944-953 (1980)