FINE STRUCTURE OPTICAL FIBER

PROBLEM TO BE SOLVED: To provide a device which exhibits a relatively large nonlinear interaction at visible and near IR (vis-nir) wavelengths. SOLUTION: A suitably designed optical waveguide exhibits an abnormal (positive) dispersion over the continuous body of the vis-nir wavelength and the fiber 10 in one embodiment exhibits zero dispersion at a visible wavelength (for example, about 760 nm). These characteristics are achieved by mutually matching a core region 12 and the refractive index difference between the core region 12 and a clad 14 (making the core region 12 relatively small and making the refractive index difference relatively large). In a more preferable embodiment, the zero dispersion point occurs at the vis-nir wavelength. For example, the optical waveguide is fine structure fiber 10 having the silica core 12 enclosed by the relative thin inner clad 14 having a plurality of capillary holes 14 and 1 enabling the refractive index waveguide in the core 12. The patterns of the cross sections of the holes are for example, hexagonal or triangular. COPYRIGHT: (C)2007,JPO&INPIT