Optical neural devices using graded index thin film waveguides

Nobel optical neural devices using graded index thin film waveguide are described. Coupling characteristics between neural input and output signals are efficiently performed with inhomogeneous refractive index control at the small focussing region in the waveguide. We investigate the inhomogeneous index distribution of waveguide type neural coupling devices for the cases where the neural signals correspond to Gaussian beams and spatial impulses.