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.

Abstract: A wide bandwidth, high sensitivity optical accelerometer having a lever arm to amplify the mechanical displacement of the accelerometer mass element. The optical accelerometer includes a high resonant-frequency spring-mass system, wherein the acceleration forces up to several hundred Hz cause a linear displacement of the mass with force, which, through the lever arm, modulates the intensity of a beam of light with a large gain. The modulated light beam is in turn converted to an electrical signal which corresponds to the applied accelerating force. The accelerometer of the present invention may be largely fabricated from a single piece of material such as silicon, wherein the lever, mass, spring and supporting structure are etched from a single substrate according to known photolithographic processes. Alternatively, the accelerometer components may be molded from a sheet plastic or other material.