Abstract: A multichannel light switch including a cylindrical-shaped light-focusing transmission body having a length equal to an odd multiple of one quarter of the pitch of light beam undulation within the body and having a total reflection coating applied to one end face thereof, which is normal to the axis of the transmission body. A stationary optical fiber bundle is arranged opposite to the other end face of the transmission body and is in parallel to the axis thereof. For light-path switching between the optical fibers, the transmission body is adapted to be displaced in a radial direction or to be rotated in a plane normal to the axis thereof.

Abstract: 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.