Abstract: Acoustic imaging apparatus wherein a beam of high frequency acoustic energy is directed to the object to be imaged to create variations in the transmitted acoustic energy which variations are then detected by a plurality of small particles suspended in the beam path for motion in response to radiation pressure produced by the incident acoustic energy, thus providing a visible image with high contrast sensitivity and excellent image resolution.

Abstract: Method and apparatus for causing light to interact with surface acoustic waves so that the light is either scattered out of or coupled into an optical wave guide. In the case of scattering when the light is propagating in an optical wave guide and chirped surface acoustic waves interact with the light, the light is scattered out of the optical wave guide into a focused beam. The focused beam of light travels in a path parallel to the surface acoustic waves and at the same velocity as the acoustic waves. The focused beam can scan objects to obtain electrical signals corresponding to the optical image of the objects and also the beam can be focused on a plurality of photodetectors to multiplex the light. In the case of coupling when the light is incident on an optical wave guide and the frequency of the chirped surface acoustic waves is selectively varied, the light is selectively coupled into the optical wave guide in a corresponding manner.

Abstract: An improved electronically focused imaging system for focusing transmitted acoustic waves into a focal line and for scanning the focal line for waves either reflected or transmitted from an object of interest. The system includes N transducer elements in a transmitter array and N transducer elements in a receiver array. These 2N elements can resolve N.sup.2 locations on the object of interest. In one embodiment the transmitter array is pulsed through a delay line that is activated by two, independent, frequency varying chirp signals. In this embodiment the receiver array is focused to scan the focal line and to develop a rectangular raster so that the output of the system is viewable on an oscilloscope or a television screen. In another embodiment the transmitter array is pulsed by a delay line activated by one chirp signal and a 45.degree. raster is developed.

Abstract: Charge storage and monitoring apparatus including a barrier electrode capable of supporting a charge adjacent a piezoelectric semiconductor to control the depletion layer and provide an output signal related to an acoustic wave in the semiconductor and the applied charge.