Optically Induced Variable Light Deflection By Anisotropic Bragg Diffraction In Photorefractive KNbO 3

Abstract

Photoinduced anisotropic Bragg diffraction in photorefractive KNb03 using the electro-optic coefficient r42=380pm/V has been studied. It has been demonstrated that, by using a noncritical configuration, a He-Ne laser beam with fixed incidence angle can be deflected within a range of 5.67 deg by changing the wavelength λ0 of the Ar+ laser beams used for recording the photorefractive grating (wavelength tuning range: 457.9nm < λ0 < 514.5nm). It is shown that for the reported interaction angles between recording and diffracted beams, the Bragg condition is noncritically fulfilled for the whole deflection range without requiring any beam tilting.