Abstract: An optical transducer for converting pressure variations to variations in amplitude of an optical signal. A first optical transmission line is positioned above a base in a manner to maintain its end face stationary while a second optical transmission line is positioned above the base in a manner to permit the axis to be displaced from the axis of the optical fiber with the stationary end face in accordance with variations of pressure applied thereto. Optical signals propagating in one of the optical transmission lines will couple to the other with a coupling factor dependent upon the axial displacement of the optical fibers. Under conditions of continuous pressure variations, such as that created by an incident acoustic wave, the coupled optical signal will be amplitude modulated in accordance with the pressure variations.

Abstract: Optical communication apparatus is disclosed whereby the voltage controlled load device typically requiring a relatively high energizing voltage is operated by means of a wide band step-up pulse transformer and a low voltage power source. The step-up transformer permits operation of the fiber optic communication system from a power source as low as 5 volts D.C. to obtain the necessary modulation potential required by the electro-optic and piezoelectric load device.

Abstract: A method and apparatus are provided for achieving substantially uniform charging of a single layer thermoplastic recording surface in either a positive or negative sense to a potential just below the frost threshold level, for exposing the thermoplastic surface to light in image configuration, and for applying a heat pulse to the thermoplastic surface for a time relatively short compared to the duration of the light exposure interval and during that exposure. The charging event is arranged so that the thermoplastic surface is raised only to a relatively low potential with respect to ground. More specifically, the consequent surface charge density on the thermoplastic surface is of a low enough magnitude that no frost is produced when the medium is cycled without exposure to light; furthermore, the quality of the recording is relatively insensitive to layer thickness.