Abstract: An acoustic wave imaging system comprises a prism for mounting to the back surface of a piezoelectric substrate of an acoustic wave device. The piezoelectric substrate comprises a front surface on which metallic interdigitated input and output transducers mount for generating acoustic waves on or below the front surface. An electric signal source connects to the input transducer while a load connects to the output transducer. The device may also include spaced metallic reflectors. A large laser beam propagates through an entrance face of the prism, passes through the back surface of the piezoelectric crystal and internally reflects off the front surface of the piezoelectric crystal. The laser beam diffracts into a number of components due to the creation of periodic surface corrugations and or periodic refractive index perturbations beneath the surface, which are caused by the acoustic waves. The beam components exit the prism and are focused by a lens onto its image plane.

Abstract: The use of electrically conducting oxides, that permit the diffusion of hogen through the electrode material, as electrodes in the air-or H-sweeping of quartz.

Abstract: Methods are shown for deducing the point of impingement of a beam, such as particle or electromagnetic beam, on a planar detector which is much larger than the beam cross-section. The methods involve chopping the beam before it reaches the detector by means of a chopper which periodically obscures the field of view of the detector as a known function of the chopper motion, and then determining the point of impingement from output measurements of the detector and from the known geometry of the chopper and the detector.

Abstract: Single crystals of neodymium pentaphosphate greater than one centimeter in size and of high purity and quality are grown from polyphosphoric acid solutions using the combination of a dilute solution, seeding, growth temperatures of 500.degree. to 650.degree. C, and a double crucible configuration.

Abstract: A quartz surface is prepared for sweeping by a method including the steps : f(A) cleaning the quartz surface,(B) depositing a metal electrode onto the cleaned quartz surface, and(C) creating periodic openings in the metal electrode in such a manner that the metal is not disconnected by the arrangement of openings and all the metal is at one potential.