Abstract: A method and a measuring device for determining the spatial distribution of a magnetic field vector. At least a pair of sensor elements is provided. Each sensor element measures a component of the magnetic field vector. The sensor elements are aligned in a parallel, spaced-apart relationship along an axis parallel to the measured components.

Abstract: The optical response of high-quality epitaxial copper-oxide perovskite films on substrates such as LaGaO.sub.3 and SrTiO.sub.3 exhibits a nonbolometric component to a photoresponse at certain temperatures below the onset of the superconducting transition and when carrying bias currents of a certain magnitude. A nonbolometric superconductive photoresponsive cell and method employ such films. The photoresponsive cell and method of the invention can be used to detect electromagnetic radiation incident on the film and to switch or modulate electrical signals passing through the film.

Abstract: An apparatus and method for imaging the magnetic structure and the magnetic domains of a sample is described incorporating a scanning tunneling microscope (STM), a voltage generator for varying the voltage on the tip, an ammeter for measuring the current through the tip, circuitry to determine the tip voltage at zero current and a current source for passing current longitudinally through the sample. The invention may further include an applied magnetic field in the plane of the sample and orthogonal to current passing through the sample. A high density non-volatile memory is described incorporating the above apparatus except for the applied magnetic field and further incorporating a layer of ferromagnetic material having magnetic domains therein indicative of information.

Abstract: An optical apparatus and method for measuring the diffusion length in an insulating photoconductor or a semiconductor sample material, that includes a source of coherent light; means for splitting the light source and providing transmitted and reflected beams each having a variable light intensity, one of the transmitted and reflected beams being incident as a background beam at a location on the sample material, means for directing the other of the transmitted and reflected beams so as to be incident at the location as a probe beam, the directing apparatus establishing a predetermined angle between the background and probe beams at the location, polarizing means disposed in the path of the background beam and having one of two predetermined orientations corresponding to polarized and non-polarized states of the beam passing therethrough, means disposed in the path of the probe beam for periodically blocking the passage thereof; and means for measuring changes in the periodic photocurrent supplied by a power