Abstract: An apparatus and method measures and controls crosslinking treatments on a glass surface from the measurement of reflection of polarized radiation from the surface of the glass.

Abstract: A fluid monitor determines the quality, intensity and/or level of a fluid by transmitting a beam of light through the fluid and evaluating any changes to the shape of the beam as a result of being transmitted through the fluid. The monitor includes a light source and a lens which generate an incident beam of light having a predefined cross sectional shape. The beam is transmitted through a volume of the fluid, which modifies the shape of the beam as a function of the fluid quality, intensity and/or level. The beam can be polarized before being transmitted through the fluid or after beam transmission. The polarized beam is directed to a detector which evaluates the horizontal and vertical components of the beam and provides a shape signal to a detection circuit. The detection circuit processes the shape signal received from the detector to determine the quality, intensity and/or level of the fluid based on any variations from the predefined shape of the incident beam.

Abstract: A method for temperature calibration of an optical magnetic field measurement array and a measurement array calibrated by the method include an optical series circuit having a first optical transmission path, a first polarizer, a Faraday sensor device, a second polarizer, and a second optical transmission path. The optical series circuit is temperature-calibrated by adjusting the polarizer angles of the two polarizers in a special way. The calibration method functions even if the intrinsic axis of the linear double refraction in the sensor device is unknown.

Abstract: A polarizing filter control mechanism used in a camera that automatically rotates a polarizing filter in order to minimize the effects of reflected light on a photographic image. An image signal is obtained by an imaging element that converts image light of a photographic subject into an electrical signal. A level detection unit outputs a level detection signal that corresponds to the electrical signal. A minimum value detection unit compares the level detection signal with a reference signal. Using this comparison, the minimum value detection unit outputs an error signal based on a difference between the level detection signal and the reference signal. A drive control unit rotates the polarizing filter until the difference between the level detection signal and the reference signal is minimized.

Abstract: Provided is a polarization characteristic measuring method and apparatus for accurately measuring a polarization characteristic of fluorescence or Raman-scattered light emitted when a sample is exposed to light. The sample is exposed to excitation light radiated from a pulsed excitation light source and converted to p-polarized light by polarizer and half-wave plate, and photodetectors measure an intensity I.sub.pp of a p-polarized component and an intensity I.sub.ps of an s-polarized component of fluorescence emitted from the sample under irradiation with the excitation light. In similar fashion, the sample is exposed to the excitation light of s-polarized light and the detectors measure an intensity I.sub.sp of a p-polarized component and an intensity I.sub.ss of an s-polarized component of fluorescence emitted from the sample under irradiation. From these measured values, G factor is calculated according to the following equation:G=[(I.sub.pp .multidot.I.sub.sp)/(I.sub.ps .multidot.I.sub.ss)].sup.

Abstract: A method of measuring the polarization mode dispersion of a chromatic dispersion compensating optical waveguide device is provided. A force is applied multiple times to the spool flanges of a chromatic dispersion compensating optical waveguide device in order to obtain a plurality of polarization mode dispersion values which have a distribution characteristic of a Maxwellian distribution and provide a mean polarization mode dispersion value for the optical waveguide device.

Abstract: Methods for analyzing polarization mode dispersion of an optical device is provided. Various desired qualities of the device, including position dependent optical and physical qualities, can be determined. Experimental wavelength-dependent PMD data are provided that characterizes the entire optical device. The experimental data are Fourier transformed and an experimental Fourier transform is constructed. A theoretical Fourier transform is calculated and fit to the experimental transform by varying at least one parameter. Based on the fit parameters, one or more qualities, including a PMD profile of the device, can be determined. An apparatus for use with this method is also provided.

Abstract: A media detector for use in a printing device and method of differentiating between glossy-finish and matte-finish print media are disclosed. An embodiment of the media detector includes a source, sensor, and polarized filter. The source transmits an unpolarized first light signal and is positioned so that this signal is transmitted toward a sheet of print media at a first angle with respect to a normal to a surface of the sheet of print media. The sensor is positioned to detect an intensity of a reflected light signal from the sheet of print media. The polarized filter is positioned between the sensor and the sheet of print media so that the intensity of the reflected light signal detected by the sensor is less for a polarized reflected light signal than for an unpolarized reflected light signal. Polarization of the reflected light signal is dependent upon the first angle.

Abstract: For the purpose of providing a solar module which has a fixed type solar concentrator of high converging magnification, a solar cell 12 is installed on the bottom face of an extension 30 which is extended further from the apex of a V shape formed by a pair of prisms having a refractive index larger than that of air, and a mirror surface 18 is formed on the back side of an incident surface 20 on which sunlight 10 falls. The mirror surface 18 and the incident surface 20 are formed in such a manner that their distance widens toward the apex of the V shape. The sunlight 10 incident on the prisms 16 performs reflection on the mirror surface 18 and total internal reflection on the incident surface 20, respectively. After repeating such reflection, the sunlight 10 reaches the bottom of the extension 30, where it emerges as outgoing light 22 to the solar cell 12.

Abstract: An ellipsometer, and a method of ellipsometry, for analyzing a sample using a broad range of wavelengths, includes a light source for generating a beam of polychromatic light having a range of wavelengths of light for interacting with the sample. A polarizer polarizes the light beam before the light beam interacts with the sample. A rotating compensator induces phase retardations of a polarization state of the light beam wherein the range of wavelengths and the compensator are selected such that at least a first phase retardation value is induced that is within a primary range of effective retardations of substantially 135.degree. to 225.degree., and at least a second phase retardation value is induced that is outside of the primary range. An analyzer interacts with the light beam after the light beam interacts with the sample. A detector measures the intensity of light after interacting with the analyzer as a function of compensator angle and of wavelength, preferably at all wavelengths simultaneously.

Abstract: A method to obtain polarization characteristics of an optical transmission medium is disclosed. Sequentially plural different states of polarized light are launched into the optical transmission medium. Intensities of light emerging from the optical transmission medium through combinations of optical elements are measured to obtain Stokes parameters from which Stokes vectors describing the emerging light corresponding to each of the plural sequentially launched states of polarization are obtained; for at least three different launched states of polarization, descriptors are used of these launched states of polarization and the Stokes vectors describing the corresponding emerging light to calculate a Jones matrix which mathematically models the changes that the launched light when described in terms of a Jones vector is subject to when passing through the optical transmission medium; and, the Jones matrix is used to describe the polarization characteristics of the optical transmission medium.

Abstract: An optical power regulator employs a variable optical attenuator having a first birefringent element that spatially separates the input optical beam into two orthogonally-polarized beams. Both beams pass through a polarization modulator (e.g., a liquid crystal material) that rotates their polarizations to an extent determined by the control voltage applied across the polarization modulator. A final birefringent element spatially separates both beams exiting the polarization modulator into two pairs of orthogonally-polarized beams (i.e., two horizontally-polarized and two vertically-polarized components). The thicknesses and optical properties of the birefringent elements are selected so that two of the four beams are combined by the final birefringent element to exit at the output port of the regulator, while the remaining two beams are blocked.

Abstract: Disclosed are laterally compact ellipsometer, polarimeter, reflectometer and the like material system investigating systems, and methods for their use. Input and output optical elements effect changes in orientation, (propagation direction), of a beam of electromagnetic radiation caused to pass therethrough by an essentially total internal reflection therein. In addition, a propagation direction diverted beam of electromagnetic radiation can be simultaneously, optionally, caused to have a phase retardation entered between orthogonal polarization components thereof by at least one of the input and output optical elements. The present invention enables relatively simple investigation of a sample system with a polarized beam of electromagnetic radiation which impinges thereupon at a less than Brewster Angle, small "spot" size effecting angle-of-incidence, with respect to a normal to a surface of an investigated material system.

Abstract: Two Faraday elements connected via optical connection means are assigned to a conductor. The Faraday rotation of the linearly polarized measuring light that has traversed the first Faraday element only is used as the measure of a current in a first measuring range. The Faraday rotation of the linearly polarized measuring light that has traversed both Faraday elements is used as the measure of a current in a second measuring range.

Abstract: An optical write apparatus includes a light source unit, a first image-forming optic, a beam deflector, a transparent plate, a second image-forming optic, and a photosensitive body, the transparent plate being provided at a predetermined angle .alpha. with respect to a main-scanning direction on a scanned surface so that charge is built up evenly on the scanned surface.

Abstract: A glass disk substrate inspection tool uses a polarized laser beam that is directed to the first surface of the disk substrate at Brewster's angle and is then transmitted through the disk substrate to a light detector that generates a signal representative of the intensity of the light received. Because the light polarized parallel to the plane of incidence, i.e., the plane formed by the line of the incident beam and a line perpendicular to the surface of the disk substrate, is completely transmitted, there is no surface reflection at either the first or second surfaces of the disk substrate. The polarized beam is directed by a first rotating scanner to the input of a telecentric lens assembly that provides an output beam parallel to its optical axis as the beam is being scanned. The beam is then directed by a first fixed mirror to strike the first surface of the disk substrate at Brewster's angle as the beam is scanned along a line across the first disk surface.

Abstract: An optical pickup system reads an information signal stored on a recording surface of an optical disk. The optical pickup system comprises a light source for generating a light beam including a P and an S polarization component with a wavelength .lambda..sub.1, a 1/4.lambda.

Abstract: A high contrast imaging system (10) having an adaptive focal plane (52). The system (10) includes receiver optics (32) that receive radiation (30) from both a detected target (16) and a laser beam (14) incident thereon, and a polarizing beam splitter (44) that splits the radiation into a first beam of reflected laser radiation and a second beam of radiation (46). The polarizing beam splitter (44) linearly polarizes the second beam of detected target radiation (46). A beam polarizer (48) circularly polarizes the second beam of detected target radiation (46). An adaptive focal plane or micromirror array (52) reflects the circularly polarized detected target radiation back through the beam polarizer (48) to linearly polarize the reflected, second beam of radiation (46). A detector array (56) detects the reflected, second beam of radiation (62) and outputs a signal to tracker electronics (22) in accordance with the intensity of radiation.

Abstract: Two light signals pass through a series connection of a first multimode optical fiber, a first polarizer, a Faraday sensor device, a second polarizer an a second multimode optical fiber in opposite directions. The polarization axes of the two polarizers are set at a polarizer angle .eta. or .theta. to the natural axis of the linear birefringence in the sensor device with cos(2.eta.+2.theta.)=-2/3. The measuring signal is derived as the quotient of two linear functions of the light intensities of the two light signals after passing through the series connection.

Abstract: A method and apparatus for optically assaying a targeted substance in a sample using a diffraction anomaly grating sensor. The optical sensor has a diffraction grating coated with at least one dielectric layer such that the sensor is sensitized to interact with the targeted substance. Upon interaction, light incident upon the sensor at a particular angle propagates through the dielectric, thereby exhibiting a dip in zero-order reflectance. Advantages of the present invention include facilitating increased sensitivity while protecting the metal grating from tarnishing and degradation. The present invention also allows for the construction of sensors that are sensitized to a plurality of substances, thus eliminating the need for an operator to reconfigure the sensing system in order to assay different substances.

Abstract: The illumination method and apparatus used to form micro patterns, which can determine an ellipticity exhibiting optimum contrast gap and contrast by deriving a polarization distribution function by use of equations induced in accordance with the vector image theory and deriving S and P-polarized components (S.sub.com and P.sub.com) (these components are perpendicular to and parallel to a meridional plane, respectively) of polarized light having x and y-directional components entering an illumination mask, thereby, preventing a contrast difference resulting from a contrast gap generated in the conventional linear polarization method, namely, an inconsistency between the longitudinal direction of the pattern and the polarization direction. Accordingly, it is possible to easily use appropriately elliptically polarized light, thereby being capable of achieving a reduction in contrast gap while achieving an improvement in contrast.

Abstract: Two Fabry-Perot interference filters are used as tandum polarizers for a h-power laser beam counter measure in an optical scene. The scene radiation is directed on one polarizer; one plane of polarization of the laser beam is transmitted thereby and the other scene radiation is reflected to the other polarizer. The other polarizer transmits the other plane of polarization of the laser beam and reflects the other scene radiation to a photodetector, such as an image intensifier, infrared imager, television camera tube, or a human eye. The laser beam transmitted by the polarizers is trapped by absorbers and cannot harm the photodetector.

Abstract: A portable, low cost, laser detection system which generates an alarm signal that can be used to produce visual and/or audible warnings indicating the range, location and type laser energy detected. Such laser detection system utilizes a cooperating quadraplex sensor assembly, to provide a complete 360 degree laser detection coverage, mounted on a helmet assembly which includes a helmet shell, a cushioned impact liner coextensive with the interior surface of the helmet shell and a suspended crown support liner the combination of which provides enhanced protection of the user and stabilization of the laser detection system.

Abstract: A surface plasmon resonance sensor includes a light source 10 and a polarizer 18 for producing polarized light which passes through a transparent body 12 and strikes a thin conductive film 26 disposed on the exterior surface of the body 12. The film 26 exhibits surface plasmon resonance when the light strikes the film at a "resonance angle". By determining the angle at which surface plasmon resonance occurs, the refractive index of the material on the side of the film 26 opposite to the side which reflects the polarized light can be measured.

Abstract: A pressure sensor includes two birefringent media, one of which is exposed o pressure to undergo pressure-variable birefringence. Polarized light passes through the birefringent media to be modulated in accordance with the pressure and is then made incident on a photodetector to detect the modulation. The use of two birefringent media provides temperature compensation.

Abstract: An object reflector detecting apparatus for identifying an object reflector by emitting a light from a polarized light source toward the object reflector and then detecting a reflected light from the object reflector characterized in that the light emitted from said polarized light source is a polarized light of which direction of polarization is specially defined, the polarized lights between said reflected light and said emitted light are different in the direction of polarization, and said object reflector detecting apparatus is adaped to detect only a component of the direction of polarization from said object reflector.

Abstract: An optical pickup system reads an information signal from stored on a recording surface of an optical disk. The optical pickup system includes a light source for generating a light beam including a P and an S polarization component with a wavelength .lambda..sub.1, a 1/4.lambda. plate for changing the polarization component of the light beam transmitted therethrough, an optical detector for detecting the information signal off the optical disk, and a beam splitter, provided with a first and a second surface, the first surface being capable of reflecting one of the polarization components to the optical disk through the 1/4.lambda. plate and transmitting the light beam reflected from the optical disk changed its polarization component by passing through the 1/4.lambda. plate to the second surface being capable of reflecting the light beam impinging thereon to the detecting means, thereby allowing the optical pickup system to read the information signals off the recording surface.

Abstract: An optical anisotropy measurement apparatus including a light source emitting a light beam and a photodetector disposed opposite to the light source is provided for measuring an optical anisotropy of an object to be examined disposed between the light source and the photodetector so as to intersect a straight line connecting the light source and the photodetector. The apparatus further includes: a supporting member for supporting the object to be examined rotatably about a rotation axis extending perpendicular to the straight line, a polarizer positioned between the light source and the object to be examined, an analyzer positioned between the object to be examined and the photodetector, and an optical member disposed between the light source and the object to be examined so as to cause the beam to pass through an intersection of the straight line and the rotation axis.

Abstract: A method and apparatus for inspecting a reflective surface, or material on such surface, such as lubricant and planarizing layers on a substrate surface. A beam of controlled polarization impinges obliquely at a spot in the plane of the substrate. A collector such as an integrating sphere is spaced away from the substrate and has an opening oriented to catch the oblique specular reflectance from the surface. Preferably the opening is substantially larger than the beam, so that substrate run out does not send the beam astray or defeat its measurement, and the oblique beam is aimed at an angle lying between the Brewster angle of the lubricant and that of the adjacent layer. A temperature-controlled laser diode with constant-current driver provides a beam that is free of wavelength hops and amplitude changes, making beam aiming repeatable and allowing point-by-point comparisons of the detected reflectance.

Abstract: A light intensity controlling device has a beam splitter which splits light fluxes emitted from a plurality of independently controlled semiconductor lasers, guided by optical fibers, into monitor light fluxes and main light fluxes. A gain adjusting circuit corrects the changes of output of light receiving elements depending on the polarization states of the light fluxes incident into the beam splitter. The changes result from the polarization characteristics of the optical fibers and/or the beam splitter. Alternatively, a filter is provided at one of the light receiving elements to compensate for the changes, thus providing a corrected output signal. Laser control circuits control the light emitting intensity of each semiconductor laser based on corrected output signals. The light receiving elements are set at an angle to the incoming light as so to avoid directing reflected light back toward an imaging system or the lasers.

Abstract: A bill or security discriminating apparatus includes at least one irradiating device for irradiating a surface of a bill or security at a predetermined angle with the surface thereof, at least one polarization separating device for receiving light reflected by the surface of the bill or security and separating the received light into P-polarized light and S-polarized light, at least one first light detector for photoelectrically detecting the P-polarized light separated by the at least one polarization separating device and generating an electrical signal in accordance with intensity of the detected light, at least one second light detector for photoelectrically detecting the S-polarized light separated by the at least one polarization separating device and generating an electrical signal in accordance with intensity of the detected light, and a discriminator for discriminating the bill or security in accordance with the intensity of the P-polarized light and S-polarized light based on the electrical signals

Abstract: An apparatus and method for a multi-axis wheel transducer are disclosed. The apparatus of the invention comprises a wheel transducer for measuring the loads and moments acting on a vehicle wheel. Tubular load cells positioned in a radial fashion around the perimeter of the transducer hub join the rim and hub. Loads and moments acting on the rim of the wheel are transferred through the spoke-like load cells to the hub of the wheel. Sensors strategically positioned around the circumference of the tubular load cell monitor the intensity of the loads and moments. To detect angular position of the wheel, a light source generates a cone of polarized light to flood the wheel of the vehicle and detector-polarizing filter pairs detect an angle of the polarization relative to the wheel to determine its angular position. The transducer hub computer processes the sensor data and transfers the information via infrared signal to a computer located in the fender of the vehicle.

Abstract: An ellipsometer, and a method of ellipsometry, for analyzing a sample using a broad range of wavelengths, includes a light source for generating a beam of polychromatic light having a range of wavelengths of light for interacting with the sample. A polarizer polarizes the light beam before the light beam interacts with the sample. A rotating compensator induces phase retardations of a polarization state of the light beam wherein the range of wavelengths and the compensator are selected such that at least a first phase retardation value is induced that is within a primary range of effective retardations of substantially 135.degree. to 225.degree., and at least a second phase retardation value is induced that is outside of the primary range. An analyzer interacts with the light beam after the light beam interacts with the sample. A detector measures the intensity of light after interacting with the analyzer as a function of compensator angle and of wavelength, preferably at all wavelengths simultaneously.

Abstract: An optical pickup is provided which detects information contained in an optical disk. The optical disk includes a light source, a hologram device, an objective lens, a photodetector, and a single chip. The light source is formed of a first vertical cavity surface-emitting laser (VCSEL) diode and emits a light beam. The hologram device converts the light beam emitted from said light source into a polarized parallel light beam and diffracts a reflected parallel light beam reflected from said optical disk to produce a diffracted beam. The objective lens focuses the polarized parallel light beam on said optical disk and converts a corresponding reflected beam into the parallel reflected beam. The photodetector is formed of a second VCSEL diode and detects various characteristics of the diffracted beam. Finally, the light source and the photodetector are integrated on the chip.

Abstract: A Spectroscopic Rotating Compensator Material System Investigation System including a Photo Array for simultaneously detecting a Multiplicity of Wavelengths is disclosed. The Spectroscopic Rotating Compensator Material System Investigation System is calibrated by a Mathematical Regression based technique involving, where desirable, Parameterization of Calibration Parameters. Calibration is possible utilizing a single two dimensional Data Set obtained with the Spectroscopic Rotating Compensator Material System Investigation System in a "Material System present" or in a Straight-through" configuration.

Abstract: A detecting apparatus capable of supporting even narrow wire widths and of detecting defects of wires in a non-contact manner is provided. The detecting apparatus comprises an optical sensor, a sensor head, and a signal processing unit. The optical sensor comprises a transparent substrate, a transparent electrode disposed on the transparent substrate, a thin film of a polymer non-linear optical material disposed on the transparent electrode, and a reflective film disposed on the thin film, and is positioned in close approximation to and without contacting an electrode to be measured on the wiring board. The sensor head comprises a light source, optical means for guiding light from the light source into the optical sensor, and detecting means for detecting reflected light from the optical sensor. The detecting means supplies the signal processing unit with a signal corresponding to the intensity of the reflected light when the electrode on the wiring board is applied with a voltage.

Abstract: Apparatus for stabilizing multiple laser sources having distinguishable optical characteristics, e.g., in polarization field or operational wavelength, comprises a plurality of semiconductor laser sources having respective lasing cavities capable of lasing within a narrow bandwidth of wavelengths and providing spectral outputs at their respective laser exit facets having different optical characteristics from one another. The spectral output beams of the sources may be coupled to respective optical fibers and the beams combined via a beam combiner, e.g., a polarizing beam combiner or a WDM combiner. The beam combiner combines the beam outputs forming a single beam which is launched into an output optical fiber. At least one feedback fiber grating is provided in at least one of the optical fibers with the number thereof depending upon distinguishable optical characteristics of the multiple laser sources.

Abstract: Disclosed is a system, and regression-based method utilizing optical data, for use in identifying material systems which have been cut to have an optical axis oriented as desired with respect to a alignment surface. The present invention is particularly well suited to qualification of material systems such as optical compensators and retarders, which ideally have an optical axis oriented perpendicular to, or parallel to, an alignment surface.

Abstract: The invention relates to a method and arrangement for target seeking, where a rotatable instrument emits an electromagnetic radiation and automatically searches for a target reflector by detecting whether reception occurs of electromagnetic radiation received by the target reflector and reflected back to the instrument. In the beam path of the electromagnetic radiation, polarization of the electromagnetic radiation, polarization modulation of the polarization direction on the electromagnetic radiation by alternately changing it, and polarization of the electromagnetic radiation take place in sequence. At least on of these steps is performed at the target reflector. Checking of the detected reflector is carried out by testing if the received radiation changes at the same rate as the modulation of the polarization direction. Only targets are accepted which give different signal strengths at said rate for the received radiation.

Abstract: A plurality of inclined planes (1419) are formed in the same substrate (1406) and a polarizing optical thin film is provided on these inclined planes. These inclined planes are filled with a transparent material so as to form a small sized and complexed polarizer. This polarizer is excellent in transmission ratio and in extinction ratio. With this polarizer, it is possible to detect a magneto-optical signal with a high signal-to-noise ratio. This polarizer is used as a cover of a package (1408) of an optical head in which a light receiving device (1410, 1411) and a light emitting device (1409) are contained in the form of a single piece. There is also provided an optical element capable of adjusting optical paths so that the optical length of a returning optical beam may be different from the optical length of a forward optical beam. With this optical element, it becomes possible to delete the initial offset in a focusing error signal, and thus adjustment process becomes unnecessary.

Abstract: An optical pick-up head for reading writing information from on a magneto-optical record medium including a semiconductor laser, a multi-image plane parallel plate for separating an incident light beam emitted by the semiconductor laser from a return light beam reflected by the optical record medium and dividing the return beam transmitted through and refracted by the multi-image plane parallel plate into a plurality of return light beams, and a signal detecting photodetector receiving a plurality of return light beams, wherein the multi-image plane parallel plate is formed by first and second prisms made of birefringent material and is arranged such that major and minor axes of astigmatism introduced by the plane parallel plate are inclined by 45.degree. with respect to an information track.

Abstract: A method of measuring surface reflectance of a polarizing film product and for producing an antireflective polarizing film. The method includes placing a linear polarizer between a polarizing film product and a light supplying part, and measuring light reflected by the surface of the film.

Abstract: A silicon wafer measuring method includes: (a) a first step of measuring a light transmission characteristic (I.sub.OBS) of the pulled silicon wafer by utilizing parallel polarized light incident at the Brewster angle into the pulled silicon wafer, (b) a second step of measuring a light transmission characteristic (I.sub.O) of a floating zone silicon wafer functioning as a reference silicon wafer by utilizing parallel polarized light incident at the Brewster angle into the floating zone silicon wafer, and (c) a third step of calculating a substitutional carbon concentration ?C.sub.SC ! on the basis of the light transmission characteristic (I.sub.OBS) of the pulled silicon wafer measured during the first step and the light transmission characteristic (I.sub.O) of the floating zone silicon wafer measured during the second step, (d) a fourth step of comparing the substitutional carbon concentration ?C.sub.

Abstract: Disclosed is a dispersive optics system, in the context of sample substrate system investigating spectroscopic reflectometer and the like systems, which, in use, produce a plurality of "Orders" of essentially single wavelength beams of light from a polychromatic beam of light. In use the availability of more than one "Order" of essentially single wavelength beams of light allows simultaneous measurement of more essentially single wavelength beams of light, over a larger range, than would be possible were only one "Order" of essentially single wavelength beams of light present. Filters are present to reduce the effects of stray light on detector elements and to allow separating the wavelengths in overlapping regions of adjacent Orders. Also disclosed is a quadrant detector means of dispersive optics alignment, and a compensator means for reducing the effect of detector element polarization state dependence.

Abstract: Novel rotation sensors are disclosed, sensors with a temporal resolution of one measurement per rotation. A transparent or absorbing substrate can be coated with a transparent thin film to produce a linear response in reflectance versus angle of incidence over a certain range of angles. The best results were obtained when the incident light was s-polarized. For example, a Si substrate coated with an SiO.sub.2 film was used in constructing a reflection rotation sensor. Experimental results and an error analysis of this rotation sensor are presented.

Abstract: A fiber optic, Faraday-effect current sensor (optical current transducer) which has improved temperature sensitivity due to compensation for temperature-induced variations of the Verdet constant. Fiber optic sensing coils can exhibit shifts in their bias angle due to a number of reasons, including physical rotation of the fibers, an apparent circular birefringence attributable to the sensing coil shape (Berry's phase), circular birefringence in the sensing fiber, or a DC magnetic field or current. The present invention takes advantage of the change in bias angle by identifying a preferred channel from the two sensing axes of the output fiber, based on the manner in which these axes respond to the change in bias angle. One of the axes will exhibit a change in sensitivity that exacerbates the change in sensitivity due to the Verdet constant, while the other channel will exhibit a change that complements, or compensates for, the change in sensitivity due to the Verdet constant.

Abstract: In an optical current transformer, an optical sensor is made up of two optical sensor units which are independent of each other. Incident light beams are applied to the optical sensor units, and the emergent light beams from the latter are subjected to addition, to obtain a measurement signal which is proportional to a current under test which flows in a conductor. The optical sensor units are substantially U-shaped bars, which are Faraday effect glass bars which are rectangular in cross section and have 45.degree. reflecting surfaces at the corners.

Abstract: A method of accomplishing rotational alignment of laser arrays relative to an external optical axis is described. The method uses the laser polarization, which is oriented relative to the axis of the array, as the means of determining the laser array rotational orientation. The method can be rapidly executed in a manual or automatic procedure, has accuracy of better than 0.1 degree, and can be used to orient a laser array at any chosen angle with reflect to an external optical axis.

Abstract: A device for detecting polarization of light comprising a first photodetector tuned to absorb TE polarization, a second photodetector tuned to absorb TM polarization, and a circuit for comparing an output from the first and second photodetector for generating a polarization output. The first photodetector comprises a first reflector, an absorption layer on top of the first reflector, and a second reflector on top of the absorption layer. The second photodetector comprises a third reflector on top of an absorption layer, and a fourth reflector disposed under absorption layer.

Abstract: A method and system of operating a laser device includes utilizing an integral power-regulation sensor of the laser device to detect energy back reflected from an object of interest and then using the detected signal as a basis for determining a characteristic related to the object of interest. In the preferred embodiment, the determined characteristic is the position of the beam focus relative to a surface of the object. Also in the preferred embodiment, the integral power-regulation sensor is disconnected from power-regulation circuitry during the focusing operation. Interaction of the back reflected energy and the outgoing beam can be reduced by introducing beam rotation, such as by providing a quarter-wave plate along the beam path. Focusing sensitivity can be increased by locating reflective targets over the surface and by executing AC measurements to filter DC components from the signal.