Photo-induced waveguide for optical dynamic 3-D interconnections in LiNbO3

Optical interconnection is being extensively studied as one of the promising methods to interconnect signals between artificial neural units. We propose an optical interconnection scheme based on the photorefractive effect. Waveguides are fabricated in photorefractive media using the photorefractive effect by scanning a focused laser light. The refractive index change depends on the 3-D distribution of exposure. Varieties of waveguides can be made by controlling the exposure distribution in the photorefractive material. The guided optical signal can also change the refractive index of the waveguide. This property is expected to allow us to construct an optical self-organizing neural network system. In this paper, results of producing two types of waveguides in LiNbO₃ are presented.