Magnetic Controls Company

Adc Fiber Optics Corporation

Harold Roberts

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.

Unitary body optical coupler

A coupler for light between the termination of an optical fiber and one or more detector or emitter elements in which the optical path between the termination and the detectors and emitters includes one or more focussing surfaces. The coupler is designed as a molded plastic body adapted to precisely position the optical fiber termination and the emitters and detectors so that the optical path between them via the focussing surfaces couples light efficiently. The focussing surfaces are molded into the coupler during manufacture and are preferably angled to the radiation to provide total internal reflection, avoiding reflective coatings. In the case where the focussing surfaces are reflecting, they are preferably ellipsoidal or paraboloidal in shape. In a second case, one surface is beam splitting and a second surface provides focussed reflection. In another case one focussing surface is reflecting while a second focussing surface is refracting. The coupler permits the realization of various features including precise alignment between the fiber, emitters and detectors; physically separated surfaces; cross-talk elimination; insensitivity to variations in radiation wavelength, index of refraction and dimensions of the coupler; aberration correction; ease of molding without side actions in the mold; and design flexibility in the placement of the focussing surfaces.

Monolithic fiber optic coupler having total internal reflecting surface

A bi-directional, fiber optic coupler operative to receive from an optical fiber, modulated light for detection thereof, and for applying to the same fiber, modulated light for transmission to a remote location. The coupler comprises a body which can be conveniently and economically molded as a unitary plastic element and in which a V-channel is formed to receive and securely hold the optical fiber. The channel terminates in a slanted reflecting face which is readily coated with a dielectric layer to provide a beam splitting function, or in the case of dual frequency transmissions, a frequency dependent layer to provide multiplexing or demultiplexing. The slanted reflecting face is located at the bottom of an emitter cavity in which an emitter assembly is readily press-fit to provide predetermined alignment between light emanating from the emitter assembly and the reflecting face from which the light is reflected into the adjacent termination of the optical fiber. A detector cavity is formed within the body and positioned to receive light passing through the reflecting face. The transiting light is refracted downward toward the detector cavity which is positioned off axis. An index of refraction matching material may be applied between the optical fiber and reflecting face in which case the reflecting face passes the incoming light directly along the axis. A portion of the transmitted light is totally internally reflected by the bottom surface of the emitter cavity which is formed to provide a mirror surface that redirects that light toward the detector cavity. A lens may be molded directly into the coupler body to gather light passing through and refracted by the reflecting face. For the portion of light generated by the emitter and passing through the reflective face, a reflective wedge is provided in the bottom of the coupler body to direct that radiation away from the detector to reduce cross talk.

Growing community of inventors

Westboro, MA, United States of America

Harold Roberts