Patent ID: 7218813
Filing Date: 2007-05-15
Classification: G02B

Abstract:
1. An optical communication system comprising: an optical fiber having a spherical end surface at at least one end thereof, wherein radiant light emitted from the spherical end surface has a numerical aperture of not larger than 0.35; and an optical communication module which has a light receiving element and receives the radiant light emitted from the spherical end surface of the optical fiber, wherein, when the one end of the optical fiber is inserted in a prescribed portion inside the optical communication module, a light receiving surface of the light receiving element is located at a distance, d, from an apex of the spherical end surface of the optical fiber, and assuming that a diameter of the optical fiber is D, a radius of curvature, R, of the spherical end surface is r*D, a refractive index of a core of the optical fiber is n, and a refractive index of a substance that exists between the spherical end surface of the optical fiber and the light receiving element is n within a range of 0<d≦r*D/(n−n within a range of D≦d≦r*D/(n−n