Abstract: A polarizing point-diffraction plate is used to produce common-path test and reference wavefronts with mutually orthogonal polarizations from an input wavefront. The common-path test and reference wavefronts are collimated, phase shifted and interfered, and the resulting interferograms are imaged on a detector. The interference patterns are then processed using conventional algorithms to characterize the input light wavefront.
Type:
Grant
Filed:
August 29, 2003
Date of Patent:
June 6, 2006
Assignee:
4D Technology Corporation
Inventors:
James E. Millerd, Neal J. Brock, John B. Hayes, James C. Wyant
Abstract: A method of obtaining particulars or characteristics of an ophthalmic lens by detecting a fluorescent light which is emitted from the ophthalmic lens upon exposure to an excitation light (UV light). The particulars or characteristics of the ophthalmic lens include, for instance, identifying marks such as characters, figures, symbols, etc. which are formed in the ophthalmic lens to identify the ophthalmic lens, a thickness of the ophthalmic lens such as a contact lens and an intraocular lens, and an angular position of the ophthalmic lens, particularly of a special contact lens having circumferential portions having respective different thickness values.
Abstract: A light pulse from an ultrashort pulse light source 11 is split by a beam splitter 12 and guided, to a detection medium 4, as an excitation pulse and probe pulse having respective predetermined linearly polarized states by an excitation optical system 2 and probe optical system 3, respectively. A light track region which is generated in the detection medium 4 by incidence of the excitation pulse, and in which the refractive index is changed by a nonlinear optical effect, is irradiated with the probe pulse. Of components which have passed through the detection medium 4, a probe pulse component whose polarized state has changed through the light track region is detected by a camera 53 via an analyzer 51 in a photodetection part 5. This realizes a light track observation apparatus capable of directly observing the light track of an excitation pulse.
Abstract: An interferometric measuring method and device for measuring the shape of, or the distance to, surfaces are provided, in which light is generated, modulated with respect to its frequency, conducted to both an object surface and a reference surface, brought to interference, and conducted to a photodetector, and, to detect the particular distance, a phase of the photodetector signal is evaluated. A simple, rugged configuration, with the capability of taking a high-resolution measurements in the context of a large unambiguity range, is achieved in that the phase is considered in at least two different instants with the wavelengths that correspond on the basis of the frequency modulation, and the results are fed to the evaluation.
Abstract: A fiber optic sensing coil is formed by winding a non-coated optical fiber in a substantially circular loop. The non-coated optical fiber includes a core and a cladding. Once the non-coated optical fiber is wound, turns of the non-coated optical fiber are fused so that the cladding of the individual turns of the optical fiber are fused to one another at points of mutual contact.
Abstract: A scanned optical system for use in optical probing applications provides a large Field of View (FOV) for objective lenses having high Numerical Aperture (NA), such as Solid Immersion Lenses (SIL's). This enables high resolution imaging of semiconductor devices for such applications as laser probing, TIVA/LIVA, OBIRCH, and photon emission timing analysis. A hybrid scanning optics configuration is disclosed to provide high resolution imaging over a small area along with low resolution imaging over a large area.
Abstract: A virtual-tight-wire system is provided for determining a centerline in a large rotary machine (10). The virtual-tight-wire system includes a columnar light source (30) that is positioned at one end of the rotary machine (10). A columnar beam of light (32) is emitted from the light source (30) toward light receivers (26) in a first and second centering tool (24). The beam of light (32) is adjusted to impact the center of the light receivers (26). Once the beam (32) has been aligned, the beam acts as a virtual tight-wire for identifying a centerline of the rotary machine (10).
Abstract: In accordance with the preset invention, an optical interferometer employed as a current sensor is provided with visibility compensation and scale factor compensation. In accordance with the present invention, the interferometer is constructed so as to propagate a pair of optical beams along a defined optical path, where the optical interferometer includes a pair of optical beams that travel along at least a portion of the defined optical path such that a phase shift is induced between the pair of optical beams in response to a measureand, for example electrical current. At least one photodetector is responsive to at least a portion of the sum of the pair of optical beams and provide a beam output signal indicate thereof. From the beam output signal, a first signal is derived that is indicative of the visibility of the interferometer.
Abstract: Spectrometer instruments are characterized by classifying their spectra into previously defined clusters. The spectra are mapped to the clusters and a classification is made based on similarity of extracted spectral features to one of the previously defined clusters. Calibration models for each cluster are provided to compensate for instrumental variation. Calibration models are provided either by transferring a master calibration to slave calibrations or by calculating a separate calibration for each cluster. In one embodiment, a simplified method of calibration transfer maps clusters to each other, so that a calibration transferred between clusters models only the difference between the two clusters, substantially reducing the complexity of the model.
Type:
Grant
Filed:
June 16, 2004
Date of Patent:
May 2, 2006
Assignee:
Sensys Medical, Inc.
Inventors:
Kevin H. Hazen, Thomas B. Blank, Stephen Monfre, Timothy L. Ruchti
Abstract: A system for inspecting seal integrity of a sealed package including a visual inspection system and a medical packaging system having an integral peel testing device.
Abstract: Time-correlation methods for determining pulse characteristics from a modelocked ultrafast laser include a cross-correlation method and an auto-correlation method. In the cross-correlation method, pulses from the laser and pulses from another modelocked laser are incident on a two-photon detector that responds when the pulses overlap in time. The lasers are synchronized to the same frequency and the phase difference between pulses from the two lasers is varied to vary the temporal pulse overlap while recording the detector response. Pulse characteristics are determined from recorded data representing the detector response as a function of phase difference. In the auto-correlation method, pulses from one laser are divided into two components. One component follows a fixed delay path before being temporally overlapped at the detector with another component that has not been delayed. The temporal overlap is varied by varying the pulse repetition frequency.
Abstract: A polarimeter simultaneously measures the Stokes vectors of a light beam using an optics unit with a slit with a slit axis, a foreoptics that focuses the light beam from the point location through the slit, a collimator that receives the light beam from the slit and collimates the light beam, a cylinder lens that receives the light beam from the collimator, wherein the cylinder lens has a cylindrical axis parallel to the slit axis, a re-imaging lens that images the light beam from the cylinder lens onto a focal plane, and a set of polarizing filters including three polarization filters having three different polarizations. The polarization filters are adjacent to each other in a direction perpendicular to the slit axis and lie between the cylinder lens and the focal plane so that the light beam is directed onto the set of polarizing filters.
Abstract: The present invention relates to an FTIR spectrometer comprising a single-element detector to analyze a detector light beam emitted by a sample, with a unit to digitize the voltage available at the detector output and with a unit to process the digitized voltage. The single-element detector and the dedicated unit to digitize the detector voltage are located immediately adjacent to each other.
Abstract: Interference measuring apparatus for detecting a plurality of different interference phase signals. The apparatus has a light dividing member for dividing linearly polarized light beams superposed one upon another into a plurality of light beams. The apparatus also includes a light transmitting member with a plurality of light passing portions having different light transmitting properties in conformity with the incidence positions of the plurality of light beams divided by the light dividing member. In addition, the apparatus has a polarizing plate to receive the plurality of light beams that passed through the light transmitting member.
Abstract: A method, includes illuminating a first portion of a colored region with first light from a gas discharge tube and generating a first output using a diffuse reflection of the first light from the first portion. The method further includes illuminating a second portion of the colored region with second light from a first solid state lamp and generating a second output using a diffuse reflection of the second light from the second portion. Additionally, the method includes illuminating a third portion of the colored region with third light from a second solid state lamp and generating a third output using a diffuse reflection of the third light from the third portion.
Type:
Grant
Filed:
January 7, 2002
Date of Patent:
April 25, 2006
Assignee:
Hewlett-Packard Development Company, L.P.
Inventors:
Algird M Gudaitis, Sam M. Sarmast, Tod S. Heiles
Abstract: A fiber-optic interferometer is provided. The interferometer includes a first dual-mode optical fiber for receiving a light input and exciting a first and a second spatial, modes, a first modal processor connected to the first dual-mode optical fiber for selecting the first and the second spatial modes, a second dual-mode optical fiber connected to the first modal processor for propagating the first and the second spatial modes and producing a phase shift (??) between the first and the second spatial modes in response to an external perturbation effect, a second modal processor connected to the second dual-mode optical fiber for re-selecting the first and the second spatial modes and producing a first light output interference pattern, and an analyzer connected to the second modal filter for adjusting the first light output interference pattern to produce a second light output interference pattern.
Abstract: An interferometer for receiving a measurement beam from a target location on a stage of a semiconductor lithography machine and a reference beam from a reference location separated from the target location by a separation distance. The interferometer has a reference path to be traversed by the reference beam within the interferometer and a measurement path to be traversed by the measurement beam within the interferometer. Both the measurement path and the reference path are at least as long as the separation distance between the reference location and the target location.
Abstract: A phase measuring apparatus for measuring phase characteristics of a film applied onto an object to be measured includes a shearing interference system for providing incident light onto the object or light reflected on the object with shearing interference, a detector for detecting shearing interference information, and a computing unit for calculating the phase characteristics of the film based on the shearing interference information.
Abstract: A photosensor apparatus includes a light receiving element that receives reflection light of light which is illuminated onto a reference pattern image formed on a moving member, a first illuminating unit that enters regular reflection light to the light receiving element, a second illuminating unit that enters diffuse reflection light to the light receiving element, and a light receiving optical system that conducts the regular reflection light and the diffuse reflection light to the light receiving element. Preferably, the light receiving optical system includes a lens, constitutes an image forming optical system that forms the reference pattern image on a light receiving plane of the light receiving element with respect to the diffuse reflection light, and enters to the light receiving plane of the light receiving element only a part of regular reflection light, which is reflected from substantially the same region where the diffuse reflection light is received.
Abstract: An improved differential refractometer incorporating a photodetector array is disclosed. Using a multi-element photo array provides the basis for measurement of differential refractive index values with a heretofore unattainable combination of sensitivity of measurement and concurrent range of measurement. Within the large dynamic range attainable, the detector structure provides equal sensitivity irrespective of deflection within the range. The transmitted light beam is tailored to provide a spatial variation of the light intensity at the array improving thereby the precision of measurement of its displacement. This in turn results in improved precision in the reported differential refractive index and in the calculation of the differential refractive index increment dn/dc. Integrating the detector array into the flow cell structure of the parent case results in a detector of exceptional sensitivity and range for sample quantities far smaller than required by conventional differential refractometers.