Abstract: A pressure sensitive field effect semiconductor device which is one element of an integrated array is disclosed. The device employs a layer of elastomer material located substantially between the gate and the current carrying channel, to effectuate the conversion of a longitudinal pressure variation to an electrical variation. The device may inherently include amplification of the electrical variation. One use for the device is in an acoustic wave detector array.

Abstract: An interferometer, that simultaneously employs two phase-quadrature reference beams of coherent light which interfere with a signal beam of coherent light reflected from a spot of a displaceable signal mirror insonified by an ultrasonic wave, permits an output signal to be derived which is proportional to the sum of the squares of the ultrasonic frequency component of the interference between the signal beam and each respective one of the reference beams. This output signal is inherently substantially proportional to the intensity of the ultrasonic wave then insonifying the spot of the signal mirror and independent of random phase drift and environmental vibrations in the interferometer. The interferometric technique of the present invention, which permits the ultrasonic wave to be in the form of pulse bursts of only a few cycles so that the output signal can be range-gated, is suitable for use in an ultrasonic-wave measurement and image display system.

Abstract: The present system permits image of internal structure of ultrasonic wave scattering object to be visually revealed on a cathode ray tube display with good contrast and good resolution, even when acoustic attenuation characteristics of object are relatively uniform and scattering points in object are due substantially to differences in acoustic index of refraction. This is accomplished by employing an acoustic quarter-wave plate to relatively phase shift unscattered wave energy passed through object with respect to scattered wave energy passed through object, thereby transforming a phase pattern manifesting the object's internal structure into an intensity image pattern thereof which insonifies a flexible pellicle mirror. The remainder of the system converts this pattern into a visual display on the cathode ray tube.

Abstract: A pressure sensitive field effect semiconductor device, which may be employed as a contactless switch is disclosed. The device employs at least one layer of an elastomer material which is also an electret to effectuate the conversion of a longitudinal pressure variation to an electrical variation and to create an electric field which regulates the conductivity of the current carrying channel.

Abstract: Detection of peak phase change at ultrasonic frequency in two mutually coherent interfering light components, one of which is obtained by reflection from a rigid reference mirror and the other of which is obtained by reflection from a spot of a flexible pellicle mirror which is insonified by an ultrasonic radiation pattern, will provide an output proportional to the displacement amplitude of vibration of the spot of the pellicle, if, as is the case, the round trip optical path to the rigid reference mirror is wiggled through an excursion greater than one-half the wavelength of the coherent light at a frequency which is much lower than the frequency of the ultrasonic radiation insonifying the pellicle and the displacement amplitude is very many times smaller than the light wavelength. By raster scanning the spot over the area of the pellicle in synchronism with the raster scanning of the electron beam of a C.R.T., and at the same time intensity modulating the electron beam of the C.R.T.

Abstract: A circumferential array of n transducers is used to image an object with resolution equal to that of an array over the entire bounded aperture. This is done by illuminating the object with m components of coherent wave energy, and coherently detecting the signal picked up by each of the n transducers for each of the m wave energy components to provide the coefficients of m complex numbers for each of the n transducers. Signal processing these coefficients, in the manner described in the disclosure, permits an image of the object to be displayed on a display device with resolution equal to that of an array filling the aperture.