Abstract: Planar optical waveguide comprising a nonmagnetic substrate with a first magnetooptical layer produced epitaxially on the substrate, and a second magnetooptical layer produced epitaxially on the first magnetooptical layer. Both magnetooptical layers are composed of an iron garnet-based material. The second magnetooptical layer has a refractive index n which is approximately 1.times.10.sup.-3 to 1.times.10.sup.-2 greater than the refractive index of the first magnetooptical layer. The material of the magnetooptical layers contains at least one substituent at the dodecahedral sites of the garnet lattice, in particular lead. The proportions of lead are different in the materials of the first and the second magnetooptical layer. The optical waveguide can be used for optical single mode waveguides in the near infrared spectral range (0.8.ltoreq..lambda..ltoreq.1.6 .mu.m).

Abstract: An infrared intruder detection system has two separate channels A and B. Each channel has its own pyroelectric detector device and threshold level comparator. The comparator is responsive to dual polarity pyroelectric voltage outputs produced by the associated detector device as a result of an intruder-related infrared image moving thereacross. A logic circuit analyzes the comparator outputs and responds to the identification of particular intruder-indicative sequences of comparator outputs in both channels to generate an alarm and/or switching output. The logic circuit may also identify shock-induced comparator outputs. The system offers a high intruder detection capability with immunity from false triggering.

Abstract: A thermal radiation detector comprises detecting means supported by a flexible film.To improve the absorption of incident radiation by the thermal radiation detector, the detector comprises an electrically resistive layer which is immediately adjacent the flexible film, and to which the detecting means are thermally coupled. The optical thickness of transparent dielectric material preceding the detecting means (suitably consisting only of the flexible film) is one fourth of a selected wavelength in a given wavelength range to be detected. The wavelength is selected so that the absorption of incident radiation by the resistive layer is substantially a maximum at the selected wavelength. The resistive layer may be between the flexible film and the detecting means, or it may precede the flexible film. In the latter case, an electrically conductive, reflecting layer is disposed between the flexible film and the detecting means.

Abstract: In an opto-mechanical scanner combining scanning and ranging functions the scanning beam, obtained from line-scanning means and frame-scanning means, and the ranging beam converge on a scanning detector array and a ranging detector, respectively. In accordance with the invention, the scanning beams and the ranging beams traverse an arrangement of fixed optical elements which are arranged to ensure that the beam each follow two different optical paths such that the ranging beam bypasses the line-scanning means. This ensures that the ranging beam has a fixed spatial orientation which is independent of the line-scanning means.

Abstract: The invention relates to an optical branching device which may be used as an optical isolator, circulator or switch. The device comprises two polarization-sensitive beam splitters. Each beam splitter comprises a prism and a rhombohedral plate between which a liquid crystal film is interposed. An optical device for rotating the plane of polarization of linearly polarized light is arranged between the two beam splitters. The polarization rotation device may comprise a Faraday rotator with a constant or a switchable direction of magnetization and a half-wave plate. Alternatively, the polarization rotation device may comprise a liquid crystal film interposed between two electrodes.

Abstract: Method of automatic focussing of a video pickup device having an objective and producing a digital image. According to the invention, this method comprises analyzing the image, within a window, with the aid of at least one digital operator. The digital operator takes the derivatives, in a given direction, of the contours of the image. Thereafter, the absolute values of these derivatives are computed. Finally, a quality parameter defined by the sum, in the window, of the absolute values of the derivatives is calculated. The position of the objective of the pickup device is controlled so as to maximize the value of the quality parameter.

Abstract: An image enhancement circuit for eliminating noise from a series of image signals g.sub.i (t) representing images of a quasi-stationary object in a noisy environment. The image enhancement circuit is provided with an accumulator circuit and a weighting circuit. The weighting circuit receives a difference signal indicating the difference between the actual image signal g.sub.i (n) and the output signal h.sub.i (n) of the accumulator circuit. In the weighting circuit, the difference signal is multiplied by a weighting factor k(i) which is dependent on the ordinal number i of the actual image signal g.sub.i (n). For example, k(i)=1/i. The weighted difference signal is then added to the accumulator.

Abstract: An image sensor device comprising a semiconductor substrate having a number of surface-adjoining channel regions. The channel regions are separated from each other by surface-adjoining channel separation zones. The channel regions further adjoin an underlying semiconductor zone extending substantially parallel to the surface. The channel regions have doping concentrations which exceed that of the semiconductor zone. The semiconductor zone has a dopant concentration which exceeds the dopant concentration of the semiconductor substrate. The semiconductor zone has a varying thickness which has minima at the areas of the centers of the channel regions. In such an image sensor device, a potential distribution can be obtained which strongly suppresses blooming realized at right angles to the surface that the occurrence of blooming is strongly suppressed. The invention also relates to a method of manufacturing this image sensor device.

Abstract: A method of manufacturing a passive fiber optic component, in which two or more fibers are each bared at one end by removal of the outer coating of the fiber the bare portions of the fibers are etched to produce a cylindrical end portion which adjoins a conical portion. Subsequently, the fibers (1) are arranged with their etched portions in a capillary tube which is sealed at one end. The tube is then evacuated and is fused with the etched portions of the fibers to form a solid rod with a rotationally symmetric distribution of the end portions of the fibers. The fibers are etched to such a diameter that after fusion of the fibers with the tube, the fused fibers ends have a circular cross-section substantially equal to the cross-section of a single fiber core. An end face is formed on the rod by cleaving or by grinding, and by polishing to obtain a fused fiber head.

Abstract: An infrared radiation detector device, for example, for an intruder alarm, comprises two dual detectors. Each dual detector constitutes a separate detection channel and has two pyroelectric detector elements. The detector elements are formed from pyroelectric material with electrodes on opposite surfaces. The detector elements of each dual detector are spaced apart from one another and connected in a circuit differentially to cancel out the effects of temperature changes common to both elements. One detector element of one dual detector is interdigitated with a respective detector element of the other dual detector, thus enabling the two dual detectors to respond to incoming radiation and provide outputs at, or very nearly at, the same time. In this way, when used in an intruder alarm, the risk of false triggering is reduced. The other detector elements of the dual detectors may similarly also be interdigitated.

Abstract: A container for generally flat, rectangular electronic components (so-called chips). The container comprises a tubular housing which can be closed on at least one of its ends by means of a closure member. The closure member can be clamped in at least one recess in a wall of the housing. The closure member is in the form of a key having a shaft and a handle. The shaft has, viewed in the longitudinal direction of the handle, a thickness substantially equal to the distance between the wall of the tubular housing provided with the recess and the opposite wall. The shaft has a thickened part in a direction at right angles to the longitudinal direction of the handle. The thickened part has a cross-section substantially corresponding to the dimensions of the recess. Furthermore, the distance of the handle from the thickened part corresponds to the distance of the end of the tubular housing from the recess. Consequently, the key is inserted into the tubular housing and then rotated 90.degree.

Abstract: A portion of a fiber to be positioned is transversely irradiated by means of an ultraviolet light source. The source emits ultraviolet light of such a wavelength that fluorescence is produced in the core of the fiber. The visible light produced in the core by the fluorescence is used to make observations for visually controlling the position of the fiber. In this manner, cores of light conducting fibers can be positioned very accurately even when they are arranged eccentrically in the cladding.

Abstract: Glass optical fiber having a primary coating constructed from two layers (having a total thickness 50-70 .mu.m), in which the first layer on the fiber consists of UV cured acrylate resin having a modulus of elasticity at 25.degree. C. less than or equal to 5 N/mm.sup.2. The second layer is also a UV cured acrylate resin, but has a modulus of elasticity at 25.degree. C. of from 25 to 1500 N/mm.sup.2. The ratio of the thickness of the first layer to the thickness of the second layer is between 0.5 and 2.

Abstract: An integrated optical wavelength multiplexer/demultiplexer device for monomode systems is provided in order to fully utilize the large transmission capacity of monomode transmission systems. As shown in FIG. 1, the multiplexer/demultiplexer consists of a lateral two-mode strip waveguide, to which are connected, on both sides, two monomode strip waveguides. The wavelength selectivity of this element is attained by the different mode dispersions of the two modes capable of propagating in the two-mode strip waveguide. These modes are coupled to the monomode strip waveguides by adiabatic mode conversion. The element has a periodic wavelength dependence based on the operating principle of the two-mode interference. This dependence is utilized to construct compact multichannel multiplexer/demultiplexer devices in the form of cascaded, branching multiplexer/demultiplexer elements.

Abstract: The invention relates to an image detector for a camera operating in a "day" mode and a "night" mode. The detector comprises an evacuated envelope containing a semitransparent photocathode for the transmission of incident photons or for converting photons into photoelectrons, depending on whether the mode is "day" or "night", respectively. The detector also comprises a detector capable of converting the incident photons or the photoelectrons into an electrical image signal. The image detector further includes electronic means for focussing the photoelectrons onto the detector, and optical means for focussing the photons onto the photocathode or onto the detector. The photocathode comprises a thin layer having at least one active layer of a III-V n-type material. The detector consists of a two-dimensional charge transfer device. The electronic means for focussing the photoelectrons on the charge transfer device comprises proximity focussing means.

Abstract: A device for coupling a light source and an optical waveguide. The light source has an emissive surface whose dimensions are of the same order of magnitude as or smaller than the cross-sectional dimension of the waveguide. The coupling device comprises a ball lens, which is contact with the light source, and a convergent optical transfer system. The optical transfer system images the input face of the waveguide to the optical center of the ball lens with a magnification of approximately -1. The radiation issuing from any point of the emissive surface of the light source enters the waveguide as parallel rays.

Abstract: Method of manufacturing a semiconductor device and semiconductor device manufactured by the use of such a method.A method of contacting narrow regions, such as narrow polysilicon gates of a CCD, having widths of, for example, 4 .mu.m. Upper layers, which are required for the CCD electrodes, are used as etching masks for contacts to the lower electrode layers. Two upper layers define two contact openings of 4 .mu.m which are displaced both with respect to each other and with respect to the region to be contacted. Therefore it is possible to define a contact opening which is smaller than 4 .mu.m and which is aligned accurately above the gate to be contacted.

Abstract: A television camera tube comprising in an evacuated envelope, an electron gun for generating at least one electron beam. The electron beam is focused onto a target, and is deflected over the target. A grid electrode having hexagonal apertures is provided in front of the target.The apertures in the grid electrode are arranged in a honeycomb structure. Each aperture has the form of an equilateral hexagon having angles of 120.degree.. As a result, the susceptibility to Moire effects is reduced, the microphonic properties are improved, and the mesh obtained has a high transmissivity while it can more readily be tensioned and is easier to handle.

Abstract: An optical connector for coupling pairs of optical fibers. The connector comprises a multi-part housing accommodating two pin holders. Each pin holder encloses one or three pins which enclose an elongate duct for accommodating one end of an optical fiber. The pins are aligned with respect to each other by means of a coupling bushing. A set of pins projects beyond a first housing part and is protected by a protective cap which is detachably mounted on the housing part and which projects beyond the end of the set of pins. A coupling bushing is arranged on the pins inside the protective cap. A collar formed on the protective cap keeps the coupling bushing in position. The protective cap also serves for precentering during the assembly of the connector. To this end, the protective cap forms a smooth fit with a recess in a second housing part within which the second, mating pin holder is accommodated.

Abstract: A magnetic device comprising a first and a second plate of a magnetic material between which domains are situated. An interaction force occurs between the domains in the two plates. Stable domain positions in a second plate define equally stable domain positions in a first plate. One or both plates can be provided with domain guiding structures. Domain displacement in one plate can control a domain displacement in the other so that a variation in the interaction force is produced.