Abstract: The present invention provides a method including measuring a wavefront aberration of the optical system to be measured on a measurement surface, measuring a pupil transmittance distribution of the optical system determining a pupil function of the optical system based on the wavefront aberration and the pupil transmittance distribution, and performing imaging computation using the pupil function to obtain a light intensity distribution formed on an image plane of the optical system, and calculating a flare, generated in the optical system, from the light intensity distribution.

Abstract: Measurement of Brillouin scattered light is enabled without an optical receiver having a wide reception band.

Abstract: An optical position-measuring device is arranged for recording the relative position of a scanning unit and a scale movable to it in at least one measuring direction. The scale is configured as a combined unit which includes at least one reflector element as well as a measuring graduation. A light source and one or more detector elements are assigned to the scanning unit. The scanning unit includes splitting device(s) which split the beam of rays, emitted by the light source, into at least two partial beams of rays in the measuring direction, which after being split, propagate in the direction of the scale.

Abstract: Apparatus and method for increasing the sensitivity in the detection of optical coherence tomography and low coherence interferometry (“LCI”) signals by detecting a parallel set of spectral bands, each band being a unique combination of optical frequencies. The LCI broad bandwidth source is split into N spectral bands. The N spectral bands are individually detected and processed to provide an increase in the signal-to-noise ratio by a factor of N. Each spectral band is detected by a separate photo detector and amplified. For each spectral band the signal is band pass filtered around the signal band by analog electronics and digitized, or, alternatively, the signal may be digitized and band pass filtered in software. As a consequence, the shot noise contribution to the signal is reduced by a factor equal to the number of spectral bands. The signal remains the same. The reduction of the shot noise increases the dynamic range and sensitivity of the system.

Abstract: A system for positioning a product, comprising a chuck for supporting the product, an intermediate stage supporting said chuck, and a stationary base supporting said intermediate stage. The chuck can move with respect to the intermediate stage in a first direction X, and the intermediate stage can move with respect to said stationary base in a second direction Y. The system furthermore comprises at least one laser interferometer for measuring the position of the chuck relative to the stationary base. The main part of the laser interferometer is attached to the intermediate stage, so that it can measure the distance between a reflector on the chuck and a reflector on the stationary base.

Abstract: A device for determining the position of a structure (3) on an object (2) in relation to a coordinate system is disclosed. The object (2) is placed on a measuring table (20) which is movable in one plane (25a), wherein a block (25) defines the plane (25a). At least one optical arrangement (40, 50) is provided for transmitted light illumination and/or reflected light illumination. The optical arrangement (40, 50) comprises an illumination apparatus (41, 51) for reflected light illumination and/or transmitted light illumination and at least one first or second optical element (9a, 9b), wherein at least part of the at least one optical element (9a, 9b) extends into the space (110) between the block (25) and an optical system support (100). The block (25) and/or the optical system support (100) separates the illumination apparatus (41, 51) spatially from the plane (25a) in which the measuring table (20) is movable.

Abstract: An exemplary embodiment of apparatus and method to measure and filter the spectrum of electro-magnetic radiation using multiple dispersive elements, such as diffraction gratings or VIPA etalons, concatenated in a cross-axis orthogonal arrangement can be provided. For example, it is possible to receive at least one first electro-magnetic radiation and generate at least one second electro-magnetic radiation using at least one first spectral separating arrangement. A first spectrum of the second electro-magnetic radiation can be dispersed along at least one first dispersive axis with respect to a propagation direction of the second electro-magnetic radiation. In addition, it is possible to, using at least one second arrangement, receive the second electro-magnetic radiation and produce at least one third electromagnetic radiation having a second spectrum dispersed along at least one second dispersive axis with respect to a propagation direction of the third electromagnetic radiation.

Abstract: Apparatus for providing Bias-Instability reduction in Fiber Optic Gyroscopes are provided. In one embodiment, an optical circuit for a fiber optic gyroscope having a broadband light source and an optical fiber loop comprises: a PM fiber of length v; an IOC coupled to the PM fiber via a pigtail of length d1, a second pigtail with length of d2, and a third pigtail with length of d3; a splitter that splits light received from the first pigtail into a first and second beams directed to the second and third pigtails; and a depolarizer circuit coupled to said fiber loop including a first fiber section of length x, a second fiber section of length z, a third fiber section of length w and a fourth fiber section of length y; and wherein the lengths of v, x, y, d1 and d3 are proportioned to avoid regions of high bias instability.

Abstract: A laser Doppler vibrometer for vibration measurement that employs active feedback to cancel the effect of large vibration excursions at low frequencies, obviating the need to unwrap phase data. The Doppler shift of a reflective vibrating test object is sensed interferometrically and compensated by means of a voltage-controlled oscillator driving an acousto-optic modulator. For frequencies within the servo bandwidth, the feedback signal provides a direct measurement of vibration velocity. For frequencies outside the servo bandwidth, feedback biases the interferometer at a point of maximal sensitivity, thus enabling phase-sensitive measurement of the high-frequency excursions. Using two measurements, one with a low bandwidth and one with a high bandwidth, more than five decades of frequency may be spanned.

Abstract: Exemplary systems and methods for obtaining a photoluminescence radiation from at least one portion of a sample can be provided. For example, using the exemplary embodiment, it is possible to receive a first radiation and disperse the first radiation into at least one second radiation and at least one third radiation. The second and third radiations can be provided to different locations of the portion. In addition, it is possible to receive the photoluminescence radiation from the portion based on the second and third radiations.

Abstract: A device for an interferometric measuring device having a first interferometer and a second interferometer, short coherent radiation being supplied to the first interferometer via a radiation source which is split into to beam components by a first beam splitter; and the optical path length in a beam component being longer than in the other beam component to the effect that the optical path difference is greater than the coherence length of the radiation; before emerging from the first interferometer, the two beam components being recombined and supplied to the second interferometer, which splits the radiation into two additional beam components; the optical path lengths of the two beam components being different to the effect that the optical path difference registered in the first interferometer is balanced again; the optical path length for the respective beam component in the first and the second interferometer being able to be set by at least one movable optical component, and the movable optical compone

Abstract: A method and optical module for measuring relative movement of an input device and object (15) along at least one measuring axis. A laser device (3) having a laser cavity is provided for generating a measuring beam (13) in respect of each measuring axis. The measuring beam (13) is used to illuminate the object (15) and measuring beam radiation reflected from the object (15) and re-entering the laser cavity generates a self-mixing effect in the laser and causes changes in operation of the laser cavity. A detector (4) is used to generate a measurement signal representative of these changes and an electronic processing circuit (18) selects, in dependence on the speed of relative movement, one of at least two parameters of the measurement signal for use in determining the speed and direction of relative movement.

Abstract: Methods include simultaneously diffracting a beam in a first direction and a second direction orthogonal to the first direction to form a once-diffracted beam, where the beam comprises a wavefront shaped by a test object, simultaneously diffracting the once-diffracted beam in orthogonal directions to form a twice-diffracted beam, overlapping at least two orders of the twice-diffracted beam in each direction to form an interference pattern at a detector, the interference pattern being formed by multiple copies of the wavefront laterally sheared in the first direction and multiple copies of the wavefront laterally sheared in the second direction; and determining information about the wavefront based on the interference pattern.

Abstract: An optical device for changing polarization comprises a waveguide having a waveguide end facet coupled to a quarter-wave plate/reflector combination to rotate the polarization of incident light to the waveguide by 90 degrees. In one embodiment, a polarization beam splitter/rotator combination (PBSR) uses a quarter-wave plate in reflection at the end facet of the waveguide. The polarization beam splitter/rotator combination and variations of that structure are applied in various useful topologies as polarization mode dispersion (PMD) compensators and polarimeters.

Abstract: A tunable optical spectrometer includes a medium configured to perform polarization rotation within a frequency band on a linearly polarized test beam, wherein the medium is circularly birefringent, and wherein the polarization rotation is achieved based on two-photon-absorption. The medium includes a gaseous substance, a first reference laser beam having a first reference frequency, and a second reference laser beam having a second reference frequency, wherein the first reference laser beam and the second reference laser beam have a same circular polarization state.

Abstract: In an optical tomographic imaging apparatus, a wavelength of a light beam emitted from the light source is selected by a light source section filter, and the light beam emitted from the light source is split into a measurement light beam and a reference light beam. The measurement light beam is reflected from a measurement subject when the measurement light beam is irradiated, is amplified. A specific wavelength from the amplified reflected light beam is selected by an amplifying section filtering mechanism having a filter characteristic identical to a time variation characteristic of the light source section filter, and then the reflected light beam is multiplexed with the reference light beam. A tomographic image of the measurement subject is acquired from detection result of an interference light beam between the reflected light beam and the reference light beam which have been multiplexed.

Abstract: The light wave interferometer apparatus is provided and includes: a luminous flux, which is sent from the light source and divided into two portions by the luminous flux separation and composition unit, are combined with each other again under the condition that the divided luminous fluxes hold wavefront information corresponding to the surface shapes of the aspherical lens to be inspected and the reference aspherical lens by the respectively corresponding basis spherical lenses. Therefore, a wavefront difference of the aspherical lens to be inspected with respect to the reference aspherical lens is made to be interference fringe information and formed on an image pickup plane of the interferometer CCD camera. The basis spherical lenses have the basis spherical surfaces, the curvatures of which are equal to each other.

Abstract: An apparatus has an optical system detecting spectral information and having an optical scanner and a driving unit changing the optical path length by moving an optical member, a monitor, a control unit obtaining a tomographic image by performing Fourier analysis on the information and displaying the obtained image, and a unit previously setting an image on the monitor, in which the member is moved from an initial position and presence or absence of the tomographic image is determined, when the presence is detected, whether the tomographic image is normal or inverted is determined, and when the tomographic image is not the set image, the member is moved to obtain the set image, and when the tomographic image is the set image, the member is moved so that a position of the tomographic image in the depth direction coincides with a predetermined adjustment position and the driving unit is stopped.

Abstract: A tunable optical spectrometer is disclosed that includes a medium configured to perform polarization rotation within a frequency band on a linearly polarized test beam, wherein the medium is circularly birefringent, and wherein the polarization rotation is achieved based on two-photon-absorption. The medium includes a gaseous substance, a reference laser beam of circular polarization and a longitudinal magnetic field. The test beam propagates through the medium twice, once in the same direction as the magnetic field, and once in the opposite direction of the magnetic field. The test beam undergoes polarization rotation an amount that depends upon the frequency of the test beam.

Abstract: A position-measuring device includes a light source, a first grating, a second grating and photodetectors, light from the light source, which is split into partial beams of different directions at the first and second grating, being directed via a deflecting element to the detector. The deflecting element for incident partial beams having different directions has different regions, so that all partial beams directed from the deflecting element to the detector are approximately parallel.