Abstract: A needle-shaped terminal, i.e., a probe tip, is brought into extremely close proximity with an object being measured. This probe tip is formed from an optically active material and in itself is electrically non-conductive, so that it has no electrical influence whatsoever on the object being measured. When optical pulses are beamed onto this probe tip, the probe tip becomes an electric conductor and a current flows between it and the object being measured, so that the electric potential of the object can be measured. This facilitates previously impossible measurements of high-speed electric waveforms. It also facilitates high spatial resolution monitoring and control of probe tip position and characterization of measurement sites, and enables highly reliable measurements to be made inexpensively.

Abstract: A fiber-optic coil for use as the sensor loop of a fiber-optic gyroscope includes a first optical fiber segment wound as radially successive coiled layers around a coil bobbin in a first region thereof, and a second optical fiber segment wound as radially successive coiled layers around the coil bobbin in an axially adjacent second region thereof. The first and second optical fiber segments are joined to each other through a longitudinal middle portion, which is positioned in the radially innermost coiled layers of the first and second optical fiber segments adjacent to a longitudinal center of said coil bobbin. Each of the first and second optical fiber segments is wound in alternate axial directions in the radially successive coiled layers. The first and second optical fiber segments may be integrally joined to each other by the longitudinal middle portion, or may be separate from, but joined to, each other by a depolarizer across the longitudinal middle portion.

Abstract: In an infrared detector, a shutter is employed in an elastic wave element of a feedback type of oscillator containing the elastic element so that the elastic element receives infrared light intermittently. The period during which the number of peaks of the oscillation output waveform from the oscillator exceeds a predetermined value is set to be the opening or closing period of the shutter, the number of clock pulses from a clock signal generator is counted during the shutter opening or closing period, and the difference between the counted values is obtained, thereby detecting the energy of the infrared light. This detector features not only an extremely high sensitivity, but a high detection accuracy, as well as the production of a digital output.

Abstract: An electrostatic voltage sensor which includes a surface acoustic wave propagating medium and transmitting and receiving transducers coupled to the medium. The voltage sensor is provided with a separate voltage collecting member different from the electrode for applying a voltage or electric field, and the voltage obtained in the voltage collecting member is varied by a predetermined frequency for being applied to the electrode so as to detect external voltage by the variation component of the oscillating frequency.

Abstract: A method of making a polycrystalline sulphide ceramic body by sulphurizing an oxide material in a carbon disulphide atmosphere at a temperature in the range of 400-1000.degree. C and less than the transforming temperature of the sulphide, which transforming temperature represents either the decomposition temperature or the sublimation temperature inherent to the sulphide. One of the advantages of this method is that sulphides can be easily made by the very strong reduction action of carbon disulphide. This application also relates to sulphides made thereby.

Abstract: A method of making a zinc sulphide ceramic body having a low electrical resistance characterized by sulphurizing a starting oxide material consisting essentially of zinc oxide and from 0.01 atomic % to 6.0 atomic % of at least one oxide of a metal selected from the group consisting of aluminum, magnesium, nickel, cobalt, cadmium, lead, indium, bismuth, antimony, titanium, zirconium, silicon, tin, niobium, tantalum, tungsten, and the rare earth element metals in a carbon disulphide atmosphere at a temperature in the range of 700.degree. C to 1000.degree. C. This zinc sulphide ceramic body can be formed into non-linear elements such as phosphors, photoconductors, luminescent elements, varistors, piezoelectric transducers, capacitors and combinations thereof. Particularly, by using this zinc sulphide body in light emitting elements, the luminous efficiency as well as the working voltage can be improved.