Title :
Optical novelty filters
Author :
Anderson, Dana Z. ; Feinberg, Jack
Author_Institution :
Dept. of Phys., Colorado Univ., Boulder, CO, USA
fDate :
3/1/1989 12:00:00 AM
Abstract :
A novelty filter detects what is new in a scene and may be likened to a temporal high-pass filter. The current status of optical novelty filters and related devices, based upon four-wave mixing and two-beam coupling in photorefractive media, is reviewed. A detector that shows only what is not new, a monotony filter, may be likened to a temporal low-pass filter. Demonstrations of high- and low-pass and bandpass temporal image filters are then discussed. An analytical treatment of the two-beam coupling devices is given in a Laplace transform framework in the undepleted pump approximation assuming plane wave inputs. This allows a unified treatment of the various filter characteristics.<>
Keywords :
Laplace transforms; optical phase conjugation; photorefractive effect; spatial filters; Laplace transform framework; bandpass temporal image filters; four-wave mixing; high-pass filters; low-pass filters; monotony filter; optical novelty filters; photorefractive media; plane wave inputs; temporal high-pass filter; temporal low-pass filter; two-beam coupling; Band pass filters; Four-wave mixing; Layout; Low pass filters; Nonlinear optics; Optical coupling; Optical devices; Optical filters; Optical mixing; Optical pumping;
Journal_Title :
Quantum Electronics, IEEE Journal of
