Abstract: A method and apparatus are disclosed which allow for the detection of an object (14) by the generation of a radiated beam (18) and a subsequent reflection by the object (14) of a portion (20) thereof. The detection of particulate object material (16) due to a reflection of a portion (22) of the generated beam (18) is minimized.

Abstract: A method for determining the amplified spontaneous emission noise of an optical circuit, such as an optical amplifier, in the presence of an optical signal includes applying a pulsed optical signal of prescribed intensity to an input of an optical circuit under test, and detecting an output signal from the optical circuit slightly after the pulsed optical signal is switched from on to off. The output signal immediately after the optical signal is switched off represents the amplified spontaneous emission noise of the optical circuit in the presence of an optical signal of the prescribed intensity. In a first embodiment, an optical spectrum analyzer is used for detecting the output signal. In a second embodiment, the output signal is passed through a narrow band optical filter to a photodetector. An electrical spectrum analyzer displays the detected waveform. When necessary, the observed output signal is extrapolated to a time immediately after the optical signal is switched off.

Abstract: Reflection microscopy process and apparatus for examining a surface which enable the injection of highly coherent electromagnetic wave, such as produced by a laser, in a waveguide whose outlet surface is flat and transparent, at least in the zone where propagation mode of the waveguide is emitted. The outlet surface is positioned above the surface to be examined at a chosen distance so that the coupling coefficient between the particular mode of propagation of waveguide and the propagation mode of the electric field of the wave reflected by the surface and guided in return by the waveguide, depends in an essentially exponential way on the distance or can be compared, at least locally, with an exponential variation function, or is rapidly decreasing, depending on the distance, and the surface is scanned with the waveguide. In particular, the field of the invention concerns scanning microscopy, by purely optical elements and with nanometric resolution.

Abstract: A single pass color optical scanner which produces multiple color component images of a scan line region of a document at different times, but which is nevertheless capable of selective scaling of image data through adjustment of scanning speed.

Abstract: An instrument for obtaining harmonics-free signals with the aid of a periodic measurement graduation and a nonperiodic scanning graduation, wherein the centers of scanning graduation markings are staggered in accordance with a modified arcsin function.

Abstract: A scanning optical apparatus is provided with a light source, a scanning device and a detector. A light beam generated from the light source is deflected by the scanning device to be scanned on a surface to be scanned. The light beam scanning on the surface to be scanned is detected by the detector. The detector is constructed such that three or more photosensors are closely arranged adjacent one another in the scanning direction. At least one of the photosensors is a division sensor which is arranged symmetrically with respect to the scanning direction.

Abstract: A gravity orientation device comprises a cylindrical casing, a shaft rotatably mounted in the casing along the longitudinal axis thereof and having pointed ends contacting bearing surfaces located in the ends of the casing, an encoder mounted within the casing and having a fixed portion secured to the casing and a rotary portion secured to the shaft, and a weight pendulum mounted on the shaft for rotation around the shaft under the influence of gravity.

Abstract: An optical receiver circuit for receiving optical signals is described incorporating a photodetector, two coupling capacitors for coupling each side of the photodetector to respective inputs of a transimpedance amplifier, two current mirror circuits for detecting current on each side of the coupling capacitor and injecting equivalent current to the other side of the other capacitor which is at the input of the transimpedance amplifier, two low pass filters, two current sources and a transimpedance amplifier having two inputs. An optical receiver for receiving optical signals is described incorporating a photodetector having one side coupled to a reference voltage, a current source, a coupling capacitor, a transimpedance amplifier, and a circuit for injecting AC current to the input of the amplifier from the voltage developed across the photodetector.

Abstract: An optoelectronic switching node is disclosed wherein two input optical beams can be switched in the sense that they can be regenerated in either one of two output spatial locations in response to input control signals. Each one of the input optical beams is coupled to a resonant cavity detector which generates a current when its corresponding optical beam impinges on its resonant cavity. Output optical beams are regenerated by two inversion channel lasers each one of which has emitter, source and sub-collector terminals and is bistable in the sense that it can be switched on and off by currents delivered into and taken out of its source terminal. Heterojunction field effect transistors are used to selectively couple the currents generated by the resonant cavity detectors to the source terminals of the lasers in order to turn them on.

Abstract: In a method of automatically determining flaws of an object of examination according to the invention, rays of light are transmitted through on object of examination, while adjusting the depth of observation to make it agree with the focal length of a detected flaw, go down deeper than the focal length and come up shallower than the focal length and the brightness of transmitted light for each depth of observation is converted into a corresponding electric signal. Portions of the generated signal that are found outside a predetermined range of intensity are taken out as flaw signals and the obtained flaw signals are compared with a number of binarized flaw patterns prepared from various flaws that have been detected in advance to accurately determine the type, number and size of the detected flaws.

Abstract: A system for characterizing the pressure, temperature, movement and flow patterns of a fluid under high pressure within a test cell. The test cell is lined internally with adjustable rock facings. Pressure is measured within the test cell using a device employing pressure-distortable optical fibers. Fluid velocity, flow direction, and filter-cake buildup are measured with laser Doppler velocimetry. The flow pattern of the fluid is viewed using corresponding arrays of transmitting and receiving optical fibers. Temperature of the fluid is estimated using a combination of thermal sensors. The pressure, velocity, viewing and temperature systems are integral to the rock facings of the test cell.

Abstract: A method and apparatus for precise control of a galvanometer patterning system is provided in which a patterning beam (12) is deflected off of a galvanometer mirror (14) toward a work piece (10). The position of the galvanometer mirror (14) is determined by generating a measurement beam (20), transmitting it through a cylinder lens (26) and deflecting it off of the galvanometer mirror (14). The deflected measurement beam (20) is filtered through grating filter (28) having two side-by-side gratings. Light passing through the side-by-side gratings filter (28) is focused on a detector (36) through an anamorphic condenser (32 and 34).

Abstract: A light-activated transducer includes a transparent electrically-insulating substrate (2) having on one surface an electrode structure. The electrode structure includes an electrode portion (5a) containing an aperture for passage therethrough of light which has passed through the substrate, a contact pad (5c) spaced from the electrode portion, and an electrical feedthrough (5b) connecting the electrode portion to the contact pad. An insulator layer (3) is adhered to the surface of the substrate and on the feedthrough, and surrounds the electrode portion while leaving uncovered the contact pad and the electrode portion and a corresponding region of the substrate. A conductive or semiconductive cover sheet (1) is adhered to the insulator layer and supported thereby in spaced overlying relationship with the electrode portion and the corresponding region of the substrate. The, cover sheet, insulator layer, and the substrate form a cavity that, when sealed, contains an ionisable gaseous filling.

Abstract: Apparatus with an element for detecting and focusing the electromagnetic radiation emitted by the flame of a burner, and with an element formed by a light-conductive bundle of fiber optics for transmitting and separating the radiation of different wavelengths, which are received and analyzed by separate sensors.

Abstract: A tracker controller system in which a pair of photo-resistive cadmium sulfide sensors mounted in the shadow of a shade pole generate a voltage signal proportional to their resistive values which signal is delivered to a comparator circuit that causes a tracker driver to operate when the voltage signal falls outside of a voltage window established by the comparator circuit.

Abstract: Apparatus for determining the distance, accurate to within an error of no more than 1 mm, from a first position to a second position. The apparatus includes a distance marker that includes a first strip having a sequence of uniformly spaced light-reflecting (or light-transmitting) regions in one embodiment and includes a second strip having a sequence of uniformly spaced light-reflecting (or light-transmitting) regions, the two strips being positioned parallel and adjacent to each other with the positions of the light-reflecting (or light-transmitting) regions of the first strip being translated relative to the positions of the light-reflecting (or light-transmitting) regions of the second strip by a fixed translation distance. The apparatus also includes a light sensor positioned adjacent to the strip to sense each such light-reflecting region (or light-transmitting region) and/or each non-reflecting region (or non-transmitting region) as that region moves past the light sensor.

Abstract: An optical device is provided for detecting the degree of obscuring moisture or precipitation on the windshield of an automotive vehicle. A source of light, such as a light emitting diode (LED) or a laser diode, is positioned to illuminate the windshield. An optical imager and detector array senses light emitted by the source, either transmitted or reflected by the windshield, and imaged on the array. The light source and detector may be positioned in convenient, out-of-the-way locations inside or outside the windshield. When the windshield is free of obscuring precipitation, light from the source is imaged on a sensor of the array aligned with the optical axis of the imager. When obscuring moisture or precipitation is present on the windshield, light is scattered such that significant portions are imaged on sensors off the optical axis of the imager.

Abstract: An optical transmitter including a laser diode (10) and achieving automatic slope variation compensation thereof. A photodetector (12) detects the output optical signal of the laser diode. One control loop (1) maintains the mean optical signal power output constant by adjusting the bias current Ib appropriately. Another control loop (2) adjusts the modulation current Imod to maintain the a.c. optical signal power constant. This is achieved by determining a voltage V2 corresponding to the mean a.c. optical signal power by rectification and comparison with a reference Vref2 to produce an error signal .DELTA.V2. The a.c. optical signal power is thus used to indicate a reduction in slope efficiency.

Abstract: A system comprises an apparatus (20) and a cassette (1) adapted to cooperate with each other. The apparatus comprises a magnetic-head unit (32) with a magnetic head (38), further tape guides (42, 44) and projections (48, 52). The cassette comprises a magnetic tape (3) and a resilient element (100) with tape guides (101, 102). During cooperation of the apparatus with the cassette the tape guides (101, 102) are situated between the magnetic head (38) and the further tape guides (42, 44), and the tape guides (101, 102) are in contact with the projections (48, 52). This provides an additional guidance for the magnetic tape at the location of the magnetic-head unit, which improves the contact between the magnetic tape (3) and the magnetic head (38) and the further tape guides (42, 44).

Abstract: A photolithography mask structure having a novel optical focus test pattern is described. The mask structure has a non-phase-shifted, transparent substrate and includes a phase shifter of other than 180.degree. disposed between spaced, parallel opposing lines such that an alternating pattern of non-phase-shifted material and phase-shifted material is defined transverse said parallel lines. When projected onto the surface of an object measurable shifts of the test pattern corresponds in direction and magnitude with the extent of system defocus. Various alternating test pattern embodiments are presented, all of which include at least one phase shift window of other than 180.degree. in relation to the mask substrate. Further, a monitoring system and a monitoring process are discussed employing the presented mask structures.