摘要 |
A light branching and coupling device, having a light focusing transmission body, in which the refractive index distribution of the body gradually decreases from the center towards the periphery of the body in a cross-section thereof, said cross-section being perpendicular to the center axis of the body. The light focusing transmission body has a length substantially equal to a positive integral multiple of 1/4 pitch with a reflective surface positioned from an end face of the body at a predetermined distance substantially equal to an odd number multiple of 1/4 pitch. Light incident on one of two end faces perpendicular to the center axis of the body propagates undulatingly to the other end face at a predetermined pitch. |