Multi-Wavelengths Optical Switching and Tunable Filters Using Dynamic Superimposed Photorefractive Bragg Grating

We present a new scheme for all optical multi-wavelengths switching and filtering using photorefractive materials to route optical signals without converting to electronic state. For this purpose the photorefractive effect which is a nonlinear optical effect seen in certain crystals and other materials that respond to light by altering their refractive index is used. When a photorefractive material is illuminated by patterned command light of intensity I(x), a dynamic superimposed Bragg grating can be obtained which is used for optical multi-wavelength switching and filtering purposes.