| 摘要 |
PROBLEM TO BE SOLVED: To attain the compatibility of the reduction of the allowable bending radius and the reduction of splicing loss of an optical waveguide. SOLUTION: Composition of a lower cladding layer 12 and an upper cladding layer 14 which are in contact with both surfaces of up and down sides of a square core 15 is made different from that of intermediate cladding layers 13 which are in contact with both surfaces of right and left sides of the core and the specific refractive index differenceΔ<SB>1</SB>in a horizontal direction and the specific refractive index differenceΔ<SB>2</SB>in a vertical direction are made to be in a relation ofΔ<SB>1</SB>>Δ<SB>2</SB>. Since the allowable bending radius is made to be a small radius and the splicing loss in the vertical direction is relatively small by setting the specific refractive index differenceΔ<SB>1</SB>in the horizontal direction large, increase of splicing loss is suppressed. Moreover, in the case of attaining the reduction of the splicing loss by setting the specific refractive index difference small, since the specific refractive index differenceΔ<SB>1</SB>in the horizontal direction is relatively large, the allowable bending radius is prevented from becoming large, to be effective in miniaturizing a device equipped with an optical waveguide and in lowering the loss of the device. COPYRIGHT: (C)2005,JPO&NCIPI |
