Opto-optical light deflection

Abstract

Light deflection is obtained by diffraction from a transient index modulation established as a grating of variable frequency by the interference of two light beams in an optical material. We describe a technique for altering the grating frequency by shifting only the wavelength of the control beams and the use of a novel optical system to maintain the Bragg condition over a wide range of frequencies in order to achieve light deflection without loss in efficiency. A computer simulation permits us to test various designs and to select the best configurations with emphasis on those that exhibit large angular deflections with minimum Bragg detuning. This new method of light deflection allows either discrete or continuous light scanning or modulation. The experimental results confirm the calculations and we have obtained angular deflection changes larger than 11 degrees from a wavelength shift smaller than 30 nm while maintaining the Bragg condition. © 1983 SPIE.