Abstract: Methods and systems are disclosed for analyzing a scanning interferometry signal. A scanning interferometry signal is provided that is produced by a scanning interferometer for a first location of a test object (e.g., a sample having a thin film). A model function of the scanning interferometry signal is provided which is produced by the scanning interferometer. The model function is parametrized by one or more parameter values. The model function is fit to the scanning interferometry signal for each of a series of shifts in scan position between the model function and the scanning interferometry signal by varying the parameter values. Information is determined about the test object (e.g., a surface height or height profile, and/or a thickness or thickness profile for a thin film in the test object) at the first location based on the fitting.

Abstract: Apparatus and method for detecting an analyte in a sample based on optical interference. The apparatus includes a light source, detector unit and one or more disposable detector tips. The apparatus also includes an optical coupling assembly that couples light from the source to the detector tips, and from the detector tips to the detector unit.

Abstract: An interferometry method using a laser of nominally fixed—but unknown and changing—frequency and phase angle, for example, attributable to laser drift. The interference pattern is periodically sampled at a frequency considerably higher than the phase shift of the object. The wavelength is reconstructed from the sampled patterns using a correlation algorithm. The phase angle is determined using an n-bucket algorithm. After all of the complex information has been determined at all of the multiple wavelengths, the surface of the object is calculated using conventional interferometry techniques. Accordingly, laser drift—typically considered a negative attribute—is used positively.

Abstract: A spectroscopic method and system for the spectral analysis of an optical signal directed to a wavelength dispersive component having two interleaved dispersive devices. For a single wavelength, the optical signal exiting the interleaved dispersive devices includes two wavefronts generally disposed at an angle to one another and producing an interference pattern. The interference pattern is detected and subsequently analyzed via a Fourier transform to produce the optical spectrum of the input beam. The method and system are applicable in a planar waveguide environment, in reflection and transmission geometries.

Abstract: A system and method for recovering lost data in an electronic gyroscope sensor system are disclosed, which use a linear adaptive predictive technique for determining what data was lost by the gyroscope sensor system during a disruptive interval involved. More precisely, a system and method for recovering lost data in a fiber optic gyroscope sensor system are disclosed, which continuously predicts “N” future samples of sensor data and stores the last known good “L” sensor values and the calculated “L” coefficients in a non-volatile memory. In the event that the fiber optic gyroscope sensor system becomes inoperable (e.g., due to a temporary loss of power to the gyroscope or other cause of electromechanical failure), and once the gyroscope sensor system resumes operation (e.g., power is reapplied), the stored “L” coefficients are retrieved from the non-volatile memory, and are used to calculate the data lost by the fiber optic gyroscope sensor system during the inoperative period involved.

Abstract: In an optical movement information detector, light emitted from a laser diode (1) is split into a first beam (10), a second beam (11) and a third beam (12) by beam splitters (2a, 2b). The first, second and third beams are converged by a condenser lens (4) upon a surface of an object to be measured (5) to form a beam spot (13) thereon. Diffused light from the beam spot (13) is received by a photodiode (6) and an output signal of the photodiode (6) is processed by a signal processing circuit (20) including an analog-digital converter (8) and a Fourier transforming unit (9). A detecting section (21) obtains, for example, a moving velocity and a moving direction of the object based on spectrum peak frequencies obtained by the Fourier transform.

Abstract: A bandwidth meter apparatus and method for measuring the bandwidth of a spectrum of light emitted from a laser input to the bandwidth meter which may comprise an optical bandwidth monitor providing a first output representative of a first parameter which is indicative of the bandwidth or the light emitted from the laser and a second output representative of a second parameter which is indicative or the bandwidth of the light emitted from the laser; and, an actual bandwidth calculation apparatus utilizing the first output and the second output as part of a multivariable equation employing predetermined calibration variables specific to the optical bandwidth monitor, to calculate an actual bandwidth parameter; the multivariable equation comprising a symmetry sensitive term.

Abstract: A chip-size wavelength detector includes a film with laterally varying transmission properties and a position-sensitive detector. The film transmits a different wavelength as a function of lateral position across the film. The position of a spot of light transmitted through the film will shift, depending on the wavelength of the light. The shift is measured by the position-sensitive detector.

Abstract: A system, apparatus and method for performing low coherence ranging of a sample with high transverse resolution and large depth of focus can be provided. For example, an optical ranging system including a light source can be used. Certain exemplary arrangement can be provided, e.g., a first arrangement for directing light from the light source to the sample, a second arrangement for directing reflected light from the sample to a detector, at least one detector, and a third arrangement for processing light data received by the detector and which generates an image can be utilized. Further, for example, an optical element can be provided which can have a transverse resolution defined as .?ris less than or equal to about ?5 m, and a depth of focus ?z of at least about 50 ?m.

Abstract: A bandwidth meter method and apparatus for measuring the bandwidth of a spectrum of light emitted from a laser input to the bandwidth meter is disclosed, which may comprise an optical bandwidth monitor providing a first output representative of a first parameter which is indicative of the bandwidth of the light emitted from the laser and a second output representative of a second parameter which is indicative of the bandwidth of the light emitted from the laser; and, an actual bandwidth calculation apparatus utilizing the first output and the second output as part of a multivarible equation employing predetermined calibration variables specific to the optical bandwidth monitor, to calculate an actual bandwidth parameter. The apparatus and method may be implemented in a laser lithography light source and/or in an integrated circuit lithography tool.

Abstract: A fiber optic gyroscope (FOG) includes a sensing coil with a particular magnetic sensitivity magnitude and direction with respect to the geometric axis of the sensing coil. The FOG also includes a plurality of magnetic compensators. Each magnetic compensator is fabricated so as to have a particular magnetic sensitivity magnitude and direction, the magnitude being comparable to that of the sensing coil, with large tolerances relative to the magnitude and direction. The compensators are positioned relative to one another and to the sensing coil such that the combined magnetic sensitivities of the compensators cancel the magnetic sensitivity of the sensing coil.

Abstract: A motion system includes a first stage that is configured to rotate about a first axis and a second stage coupled to the first stage that includes an object carrier adapted to position an object in at least one other axis. The motion system has a novel arrangement of laser interferometer elements and axes of motion. The arrangement permits accurate and precise measurement of a position of the object carrier in up to three (or more) axes of motion even as the first stage of the motion system is tilted through relatively large angles. The novel arrangement of the axes of motion also enables very precise control of the position of the object carrier even at high tilt angles.

Abstract: The present invention includes an interferometer for VISAR. Optionally, the present VISAR system includes intracavity imaging design with converging beams and field elements to, among other possible purposes, image the array. An optional embodiment of the present VISAR system may also optionally include precision fiber arrays. Optionally, the present system may use non-collimated beams to allow intracavity access to individual channels for one or more additional delay paths.

Abstract: Adhesive system and method are provided for affixing a fiber optic coil to a hub with an adhesive in a fiber optic gyroscope. The adhesive system comprises a fiber optic coil, a substantially cylindrical hub configured to couple with the fiber optic coil, and an array of adhesive dots affixing the fiber optic coil to the substantially cylindrical hub. The method comprises forming an array of adhesive dots on an outer surface of the hub, and affixing the fiber optic coil to the outer surface of the hub via the array of adhesive dots.

Abstract: A system and method for improving the accuracy of a speckle-based image correlation displacement sensor provides ultra-high accuracy by ensuring that, in the absence of motion, the speckle image does not vary over time. In one embodiment, the speckle image is stabilized by reducing or compensating for laser diode wavelength changes. Various methods for stabilizing the wavelength include thermoelectric temperature control, measuring and correcting the wavelength by any suitable means, or providing a specific wavelength of light feedback from an external grating. Image stabilization may also be accomplished by monitoring the warm-up process of the system. Once the system is determined to have completed the warm-up process, an indicator is provided to the user to indicate that the system is ready for use. Sensor geometric configurations that reduce or eliminate wavelength-related errors are also disclosed.

Abstract: This disclosure describes fiber optic gyroscopes that have integrated power measurement capabilities, and related methods and apparatus. More particularly, it describes determining the optical power of a fiber optic gyroscope (FOG) by temporarily adjusting the phase difference between two counter-propagating light beams, measuring the change in light intensity caused by the phase difference adjustment, and using the measured change in light intensity along with known characteristics of the FOG to compute an optical power value. The temporary adjustment in phase difference is preferably done in such a manner not to disturb the normal operation of the FOG.

Abstract: An optical system includes a photolithography system, a low coherence interferometer, and a detector. The photolithography system is configured to illuminate a portion of an object with a light pattern and has a reference surface. The low coherence interferometer has a reference optical path and a measurement optical path. Light that passes along the reference optical path reflects at least once from the reference surface and light that passes along the measurement optical path reflects at least once from the object. The detector is configured to detect a low coherence interference signal including light that has passed along the reference optical path and light that has passed along the measurement optical path. The low coherence interference signal is indicative of a spatial relationship between the reference surface and the object.

Abstract: A method and an apparatus for the spatially resolved polarimetric examination of an imaging beam pencil (1) generated by an associated pulsed radiation source (9). A first and a second photoelastic modulator (6a, 6b) and a polarization element (5) are introduced serially into the beam path of the beam pencil. A control unit (8) activates a first modulation oscillation of the first photoelastic modulator and a second modulation oscillation of the second photoelastic modulator and drives the radiation source for outputting a respective radiation pulse in a manner dependent on the oscillation state of the first photoelastic modulator and/or the second photoelastic modulator. A detector (4) detects the beam pencil coming from the polarization element in a spatially resolved manner.

Abstract: An optical system includes a photolithography system, a low coherence interferometer, and a detector. The photolithography system is configured to illuminate a portion of an object with a light pattern and has a reference surface. The low coherence interferometer has a reference optical path and a measurement optical path. Light that passes along the reference optical path reflects at least once from the reference surface and light that passes along the measurement optical path reflects at least once from the object. The detector is configured to detect a low coherence interference signal including light that has passed along the reference optical path and light that has passed along the measurement optical path. The low coherence interference signal is indicative of a spatial relationship between the reference surface and the object.

Abstract: A system for detecting radiation events in a ring laser gyro is provided. The system includes one or more photodetectors, that produce photocurrent signals to monitor the ring laser gyro. Further, the system includes one or more comparator circuits actuating at one or more thresholds. The one or more comparator circuits are responsive to the photodetectors to detect when a radiation event occurs based on the photocurrent signal. The system further includes a path length control circuit responsive to the one or more comparator circuits, that restores operating conditions for the ring laser gyro when a radiation event occurs.