Unitary body optical coupler

Abstract

A fiber optic coupler easily molded as an optically transparent body and adapted to provide bidirectional transmission, multiplexing, demultiplexing, fail safe relaying, or other functions from a single coupler. The body may be molded without side actions for simplicity and accuracy of placement of critical surfaces. The body includes first and second cavities for positioning light sources, such as a solid state emitter or fiber termination, and third and fourth cavities for positioning a light receiver, such as a solid state detector or fiber in a fiber connector. Opposite each source and receiver cavity is located a reflector cavity terminating in a reflecting face formed by the air-coupler body interface and operating by total internal reflection. A slot extends into the body to position a filter such as a dichroic mirror or beam splitter between the cavities. The filter, source and receiver cavities, and reflecting faces are positioned to provide light paths from one or both sources, reflected by the associated reflective face, and passing through or reflecting off the filter. The transmitted or reflected light is then reflected off one or both of the remaining reflective faces to one or both of the receiver cavities. The reflective faces may spherical, aspheric concave, ellipsoidal, paraboloidal or flat.