Abstract: Optical waveguide and the method for making the same, in which a semiconductor laser diode and an optical isolator are formed on one substrate in a monolithic manner. At the moment, a semiconductor laser diode is made by a III-V compound semiconductor crystal, such as GaAs, InP, etc., and an optical isolator is made of iron garnet to fabricate these in monolithic, and this invention was established by developing the technology to monocrystallize at least a small part of the garnet film containing no iron which is deposited on the semiconductor substrate and to use this as the seed crystal for the said phase epitaxial growth of the iron garnet film which forms the iron garnet optical waveguide.

Abstract: A gamma ray detector suitable for use in a positron CT and others is disclosed which comprises a scintillator formed of a single crystal of cerium activated gadolinium silicate which is expressed by a general formula Gd.sub.2(1-x-y) Ln.sub.2x Ce.sub.2y SiO.sub.5 (where Ln indicates at least one element selected from a group consisting of yttrium and lanthanum, and x and y lie in ranges given by formulae 0.ltoreq.x.ltoreq.0.5 and 1.times.10.sup.-3 .ltoreq.y.ltoreq.0.1).

Abstract: An apparatus for measuring electric field by making use of electrooptic effect includes an electrooptical crystal having a crystallographically eulytite structure such as Bi.sub.4 Ge.sub.3 O.sub.12, Bi.sub.4 Si.sub.3 O.sub.12 or Bi.sub.4 (Ge, Si).sub.3 O.sub.12 as a material with electrooptic effect. The optical electric-field measuring apparatus has an increased measuring sensitivity and a stabilized temperature characteristic and scarcely disturbs the distribution of electric field to be measured.

Abstract: An ON-OFF switch device is mounted in an emergency spare tire container and assumes its ON-condition when the tire is absent from the container. A warning device is electrically actuated by the switch in such a mannner that when the switch assumes the ON-condition due to absence of the tire from the container, the warning device gives a warning.

Abstract: A scintillator formed of a ZnWO.sub.4 single crystal having an absorption coefficient less than or equal to 1.8 cm.sup.-1 for the light having a wavelength of 520 nm is disclosed which has a luminescence wavelength of 480 nm and therefore can be combined with a photodiode, and which is high in radiation detection sensitivity, short in decay time, and specifically suitable for use in computed tomography.

Abstract: A voice warning system for an automotive vehicle informs the driver of the amount of remaining fuel in voice form whenever the driver inserts the ignition key. The system comprises a fuel amount sensing unit, a ready-to-drive sensor, a voice output selector for selectively outputting a voice output designation signal according to the signal from the fuel amount sensing unit, and a voice memory where various voice outputs are stored and are outputted in accordance with the designation signal. The ready-to-drive sensor may be a key sensing switch, a seat switch, or the ignition switch. In addition, a voice warning volume is set in accordance with the car radio system volume setting via a volume memory and a voice volume selector. The voice warning sound volume is adjusted and outputted by an electronic volume controller and a speaker of the car radio system. Additionally, a timer may be used to disenable the system for a predetermined delay interval or according to a predetermined schedule.

Abstract: A fully-automatic antenna driving device comprises a radio switch consisting of a push type switch which is on only during being pushed, a self-holding circuit for self-holding an excited condition by the turning on of the push type switch, and a further push type switch which is off only during being pushed, thereby preventing an antenna from being extended only by turning on an ignition switch.

Abstract: A crystal for a scintillator is a single crystal of Bi.sub.4 Ge.sub.3 O.sub.12 containing up to 0.5% by weight of Bi.sub.4 Si.sub.3 O.sub.12 and/or up to 50 ppm of Gd. The light output of this crystal as a scintillator can be increased by about 20% as compared with the light output of the conventional crystal of additive-free Bi.sub.4 Ge.sub.3 O.sub.12.

Abstract: In growing single crystals of gadolinium gallium garnet, dysprosium gallium garnet and the like according to the Czochralski method, when the velocity of rotation of the crystal during growth of a slender part is made lower than the velocity of rotation of the crystal during growth of a body portion, single crystals free of defects such as dislocation or facet can be obtained.