Title :
Spatial fidelity of photorefractive image correlators
Author :
Meigs, Andrew D. ; Saleh, Bahaa E A
Author_Institution :
Dept. of Electr. & Comput. Eng., Wisconsin Univ., Madison, WI, USA
fDate :
12/1/1994 12:00:00 AM
Abstract :
The set of equations describing photorefractive four-wave mixing of image-bearing beams has been solved in the presence of diffraction using a perturbation analysis assuming a strong uniform backward pump and a weak conjugate. To first order, it was found that the conjugate image is bilinearly related to the forward-pump and probe images. By using a Green´s function approach, an analytical expression for the bilinear kernel was derived. This kernel, which governs the bandwidth of the conjugation system, is a function of the material parameters, the beam angles, and the crystal length. When a conjugator is used to determine the correlation between two images, the result was found to be a distorted version of the correlation image. This distortion was reduced when the image with the smallest extent was chosen as the forward-pump image
Keywords :
Green´s function methods; multiwave mixing; optical correlation; optical images; optical phase conjugation; optical pumping; perturbation theory; photorefractive materials; Green´s function approach; beam angles; bilinear kernel; bilinearly related; conjugate image; conjugation system bandwidth; correlation image; crystal length; diffraction; forward-pump image; forward-pump images; image-bearing beams; material parameters; perturbation analysis; photorefractive four-wave mixing; photorefractive image correlators; probe images; spatial fidelity; strong uniform backward pump; weak conjugate; Correlators; Diffraction; Equations; Four-wave mixing; Green´s function methods; Image analysis; Kernel; Laser excitation; Photorefractive effect; Probes;
Journal_Title :
Quantum Electronics, IEEE Journal of
