ABSTRACT
The Self-Written Waveguides (SWWs) was reported by S. J. Frisken in 1993. A permanent optical waveguide was formed in a photosensitive material of a ultra-violet (UV)-cured epoxy by emitting a cw 532-nm laser beam from a core of a single mode optical fiber. This chapter describes the refractive index of the UV-cured epoxy increases by the laser beam exposure, the self-focusing effect similar to that in the third-order nonlinear optical media. E. Fazio et al. succeeded in SWW formation in photorefractive crystals to realize 3D optical interconnections in bulk ion-doped lithium niobate crystals by forming soliton waveguides. The optical waveguide stretching from the fiber core can be used as a low-cost beam expander which converts the spot size from ∼10 to ∼50 μm in diameter with a distance of a few millimeters. The soliton waveguides construct light-induced integrated structures, which are permanently fixed, as well as digital and analog switching gates, opening a new approach toward novel integrated photonic circuits.
