Abstract: A recognition light includes a reflector having an axis and first and second annular semi-parabolic reflective surfaces which have respective focal points axially spaced apart from one another, and first and second annular lamps respectively disposed at the focal points. A cover surrounds the reflector and lamps and includes a lens for focusing the light along a plane perpendicular to the axis of the reflector, the lens including first and second Fresnel lens portions each including a convex lens and a prism lens, the convex lenses being disposed adjacent one another and transaxially aligned with the first and second lamps, respectively. A light detector detects light emitted from at least one of the lamps, a monitor circuit provides a fail signal when a characteristic of the light output of at least one of the lamps does not satisfy a specified criteria, and a control circuit first activates the first lamp and then the second lamp in response to receipt of the fail signal of the monitor circuit.

Abstract: The present invention includes a vehicle light and method for use in applications experiencing vibrational loading and wide temperature variations. The light includes a solid state illumination device and a thermal compensator in thermal communication with the solid state illumination device. The thermal compensator operates to maintain the solid state illumination device above a temperature threshold.

Abstract: A permanent magnet electric motor including a rotor having an annular arrangement of field magnets for rotation around an axis relative to a stator. An annular FG magnet arrangement affixed to an end of the rotor cooperates with an adjacent FG coil to produce a signal indicative of the rotor speed. A shunt washer of magnetically permeable material is interposed between the field magnet arrangement and the FG magnet arrangement.

Abstract: A hyperfrequency semiconductor device having external beam-lead connectors is provided with a capacitance connected in series with the inductance produced by said beam-leads, said capacitance being integrated in at least one of the latter and its value being so selected that at operating frequency of the device said capacitance compensates said inductance.

Abstract: A diode structure having connections utilizing beam leads as disclosed wherein two beam-leads are spaced apart by a diode chip and by a glass stud which is spaced away from the diode chip. Contacts are taken from the diode on its two main faces. One of the two lead-beams is formed in two separated parts in order to provide for an assembly of two metal portions and of a glass stud which forms three adjustable coupling capacitors.

Abstract: A process of aligning electro-optical devices that associate a semiconductor, laser diode or electroluminescent component with an optical component, such as an optical fiber. These devices must be aligned with a precision of from .+-.1 to .+-.10.mu.. The semiconductor component is integral with a centering part through the intermediary of a first bracket. The optical component, through the intermediary of a second bracket, is integral with a container in which is placed a hardening material. The centering part is plunged in the hardening material, with three degrees of mobility. The alignment is dynamic. When adjustment has been made, the hardening material is rapidly and rigidly fixed.

Abstract: A millimetric electromagnetic waves switch is constituted by a ridged waveguide associated to a PIN diode of which the layers P.sup.+ and N.sup.+ are very thin, of about 2 to 5 microns thickness. The width of the diode is inferior to that of the ridged part of the guide and its dimension according to the longitudinal axis of the guide is a multiple of the half-length of the guided wave.

Abstract: A high-power limiter comprising silicon PIN diodes for millimeter waves is formed by a waveguide associated with a silicon substrate wherein is formed a matrix of PIN diodes. The PIN diodes are formed throughout the thickness of the silicon substrate.

Abstract: A light emitting diode (LED) is provided which has light emission taking place through the surface of a window layer and which consist of at least one active layer between a substrate and a window layer. Under biassing, the active layer emits isotropic radiation of wave length .lambda.. The LED of the invention comprises a re-emitting layer which absorbs the part of the radiation which is emitted in the direction of the substrate and re-emits it isotropically with a wave length very close to that of the active layer. For that, the re-emitting layer is made from a material whose prohibited band height is very close to but less than that of the active layer. If the substrate is transparent, it may be situated between the emitting layer and the re-emitting layer.

Abstract: A process allowing the centering of an optical fiber in an opto-electronic head or the fiber-holder of a head in an adapter between the head and optical cable. To this effect, a certain clearance is left between the cover of the head and the main part of the fiber-holder. Then a tool is used having micrometric screws for producing permanent deformations on the periphery of the cover made from a ductile alloy, while checking the result by "dynamically" effected measurements. In the case of a fiber-holder in an adapter, a certain clearance is left between the end of the fiber-holder on the cable side and the adapter is provided with a skirt made from a ductile alloy which is deformed at certain points in a manner similar to that of the first case.

Abstract: The impedance value of the semiconductor device usable at very high frequencies is preset during manufacture.The device comprises a Gunn or Zener diode coupled to a coaxial line. The central conductor of the line is constituted by a metal wire mandrel or a metal coating deposited on a glass fibre section.The outer cylinderical conductor is a cylindrical metal coating deposited on a ring of dielectric material, such as glass and which surrounds the diode.Application to microstrip, transmitting antenna and radial cavity circuits.

Abstract: A method for fitting an optical fiber in an end fitting, the end fitting obtained constituting a connection device for connecting to another connecting device incorporating an optical fiber. A hollow cylindrical support whose lateral surface constitutes the reference surface for the position of the fiber is machined and the terminal portion of the fiber is coated with electrolytic gold deposit in the form of a frustum. Then the fiber is self-centered by force inserting the frustum and the terminal portion of the fiber which it covers in the hollow support. Levelling then occurs at the butting face of the fiber by sawing and/or grinding the projecting portions of both the frustum and fiber.

Abstract: A method of optical coupling between an optical fiber and an optoelectronic component for an optical-fiber telecommunications link is applied to the fabrication of a transmitting and/or receiving optoelectronic head. In a semiconductor wafer having a p.sup.- layer and a p.sup.+ layer, chemical etching of the p.sup.- layer is followed by n-type doping of an n.sup.+ layer at the bottom of the cavity and on the edge of the cavity. Highly accurate positioning of the optical fiber is thus ensured as well as excellent coupling between the fiber and the light-emitting diode or photodiode thus provided.

Abstract: An opto-electronic coupling head ensuring the accurate positioning, in an hermetic device, of the endmost face of an optical fiber and of the active face of an opto-electronic component. With the fiber secured in the axial bore of a fiber-holder, a system of wedges provides a bearing plane for the support of an opto-electronic component. A plate serves as a base for a cover provided with sealed through-leads for the electrical connection of the component, and mechanically independent of the component and of the fiber.

Abstract: A sealed enclosing system for coupling an emitting or receiving optoelectronic device with an optical fibre. A metal cap has an optical fibre passing therethrough in a sealed manner. A bellows tube is mounted on a base and thus provides an elastic element for connecting the fibre to an optoelectronic diode mounted on the tube. The seal is completed by a welding of the cap to the base and by passing electric supply connections through the passage ways formed by glass beads.

Abstract: A process intended for avoiding the "flip chip bonding" technique, well known for planar diodes, is provided. It is further applicable to mesa diodes and planar transistors. It comprises an essential step: the lapping of the substrate up to reduce its thickness to the same order of magnitude as the upper active layer of a semiconductor device, thus facilitating the cooling of the device through the substrate towards a heat sink. This essential step is made possible by virtue of a preliminary bonding on the upper layer of the semiconductor device of a block of silicon. According to a first alternative of the invention the block is finally eliminated and the device is a conventional one with a very thin substrate. According to a second alternative of the invention, the block is retained and lapped after addition of the heat sink, then metalized to provide a secondary way to the thermal flux.

Abstract: A method of fabricating highly miniaturized semiconductor devices which must be electrically but not thermally insulated from ground, by replacing the conventional disk of beryllium oxide with a portion of the substrate itself so as to decrease the thermal resistance. To this end one starts with a disk of "PIN"-structure silicon. On one of its faces (P or N as the case may be) one deposits by epitaxy, or forms by successive diffusions, the active layers of the device and the surdoped zones. The "PIN" diode may be reverse biased if it is desired to create a capacity between active layers and metallic support serving as heat sink. Diodes and transistors in high-frequency microelectronics obtained by the method are also described.

Abstract: A process intended for combining the "flip-chip bonding" technique with a method yielding diodes of very thin substrate forming mesa units or clumps etched out in a dielectric block embedding the semiconductor body. The process comprises, starting from a semiconductive wafer, a double mesa etching and a double lapping, each of them carried out on each side of the wafer, due to a thick dielectric layer and a thick metallic support respectively brought in at the right moment.

Abstract: Provided are compounds of the formula ##STR1## wherein R and R.sub.1 are the same or different lower alkyl groups and R.sub.3 is hydrogen or CHO--.

Abstract: Bit rate compression in a digital communications system is provided by transmitting voice information from n telephone circuits over the capacity conventionally allocated for transmission of voice information from n/2 circuits without appreciable degradation in quality. Alternatively, a doubling of the number of voice circuits may be provided with transmission at the same bit rate required for conventional transmission of voice information. Each frame period, at the transmitter, all n circuits are serviced and, utilizing an adaptive predictive encoding scheme, a maximum of only 3/8 n unpredictable samples in the given frame are transmitted over the available channel capacity.A sample assignment word (SAW), which identifies the circuits corresponding to the unpredictable samples, is transmitted therewith.