Patent ID: 7027692

Claim:
An optical fiber coupling structure for optically coupling an emission-side optical fiber and an incidence-side optical fiber, comprising: an emission-side base comprising: a coupling end surface; and an incidence-side base comprising an abutting surface; and a slope, wherein the emission-side optical fiber is secured to the emission-side base, and an end of the emission-side optical fiber is exposed at the coupling end surface, wherein the incidence-side optical fiber is secured to the incidence-side base, an end of the incidence-side optical fiber is exposed at the slope of said incidence-side base, and said exposed end of said incidence-side optical fiber has a slope which corresponds to the slope of said incidence-side base, wherein the coupling end surface of the emission-side base is abutted against the abutting surface of the incidence-side base, the emission-side optical fiber exposed at the coupling end surface of the emission-side base and the incidence-side optical fiber exposed at the slope of the incidence-side base are spaced apart with a clearance, and the emission-side optical fiber and the incidence-side optical fiber are optically coupled; and wherein a core radius r 2 of the incidence-side optical fiber is larger than a core radius r 1 of the emission-side optical fiber.