Abstract: The present invention entails a phase mask for producing a plurality of volume gratings for use as optical couplers and method for creating the phase mask. The phase mask is produced by creating a plurality of volume gratings having predetermined characteristics which allow the phase mask, when excited by a coherent light wave, to produce a plurality of volume gratings in a recording material.

Abstract: A distributed resistor-capacitor device which is highly reproducible with near ideal electrical characteristics including a substrate, an insulating layer on a major surface of the substrate, and a polycrystalline semiconductor material on the insulating layer. The polycrystalline layer is the resistor and cooperates with the substrate as the capacitor. Fabrication of the device is compatible with integrated circuit fabrication and can be used with field-effect and bipolar junction transistors.

Abstract: A cascade charge coupled delay circuit including a plurality of serial delay line sections formed on a single semiconducter wafer, said delay line sections being directly coupled to one another through the wafer and means for independently clocking each section of said lines.

Abstract: An ultrasonic bidirectional transducer array, and an imaging system including said array, wherein the array comprises a plurality of transducer elements each having a major face capable of bidirectionally transmitting and receiving ultrasonic energy and an opposite face. The transducer elements have their major bidirectional faces arrayed in a predetermined surface. Means is carried by the opposite face of each element for bidirectionally providing and receiving electrical energy across each transducer element. In the imaging system the array may be selectively scanned to provide successive displays of moving objects at a rate which gives the impression of continuous motion to a human observer.