Fiber optics communications modules

Abstract

A fiber optics coupler module has a portion defining a spherical reflective surface characterized by a self-conjugate plane having the property that a point source of light in the self-conjugate plane is imaged in the self-conjugate plane. The coupler includes first and second optical transceiver terminals adapted to register a source, detector, or fiber end at each of first and second conjugate locations within the self-conjugate plane. The reflective surface passes a fraction of light incident thereon, whereupon a portion of light diverging from the first location passes through the reflective surface along a first optical path. Similarly a portion of light diverging from the second location passes through the reflective surface along a second optical path. The coupler further includes focusing means on the side of the reflective surface remote from the first and second locations for imaging light travelling along the first optical path at a third location, and also for imaging light travelling along the second optical path at a fourth location. In a first series of embodiments, the reflective surface is partially transmissive, partially reflective for wavelengths in a given range. In a second series of embodiments, the reflective surface is a dichroic surface. In a third series of embodiments, the coupler uses a plane reflection grating and collimated light.