Abstract: Systems and methods are provided for multi-function coherent imaging comprising directing a first coherent radiation beam and a second coherent radiation beam towards a detector, where the second coherent radiation beam is spatially offset, angularly offset, or spatially and angularly offset from the first coherent radiation beam. A portion of the first coherent radiation beam and a portion of the second coherent radiation beam may be combined to form a composite beam. An object may be radiated with the composite beam. A first intensity pattern may be formed by interfering with return radiation from the radiated object with the first coherent radiation beam and a second intensity pattern is formed with the return radiation from the radiated object and the second coherent radiation beam. A detector may simultaneously record a superposition of the first intensity pattern and the second intensity pattern.

Abstract: A structured light sensor system for measuring contour of a surface includes an imaging lens system, an image capturing device, a first set of micro electromechanical system (MEMS) mirrors, and a control module. The imaging lens system focuses light reflected from the surface, wherein the imaging lens system has a corresponding lens plane. The image capturing device captures the focused light and generates data corresponding to the captured light, wherein the image capturing device has a corresponding image plane that is not parallel to the lens plane. The first set of MEMS mirrors direct the focused light to the image capturing device. The control module receives the data, determines a quality of focus of the captured light based on the received data, and controls the first set of MEMS mirrors based on the quality of focus to maintain a Scheimpflug tilt condition between the lens plane and the image plane.

Abstract: A spectral interferometry apparatus and method is provided to supply unambiguous profiles (A—scans free of mirror terms) of the reflectivity versus optical path difference and make difference between the positive and negative optical path difference or provide output in a selected interval of optical path differences. The apparatus comprises object optics that transfer a beam from an optical source to a target object (55) to produce an object beam and reference optics that produce a reference beam. Displacing means (57) are provided to produce a gap (g) between the object beam (41?) and the reference beam (42?). Optical spectrum dispersing means (7) such as a grating or a prism receive the two relatively displaced beams, and disperse their spectral content onto a reading element such as a CCD.

Abstract: System and method for assessing the occurrence of an unknown substance in a sample that comprises multiple entities. A reference library is provided comprising a plurality of reference data sets representative of at least one known substance. A first feature of the entities is assessed wherein the first feature is characteristic of the unknown substance. A region of interest is selected wherein the region of interest comprises at least one entity exhibiting the first feature. A spatially accurate wavelength resolved Raman image is obtained wherein each pixel in the image is the Raman spectrum of the sample at the corresponding location. The spatially accurate wavelength resolved image is assessed to thereby identify the unknown substance.

Abstract: A fundus oculi observation device acts as an optical image measurement device capable of measuring an OCT image such as a tomographic image of a fundus oculi, or the like, and is configured so as to calculate the signal level of the formed OCT image, determine whether the signal level exceeds a threshold value, and change the position of a reference mirror so that the signal level is determined to exceed the threshold value.

Abstract: A differential-phase polarization-sensitive optical coherence tomography system includes a polarized heterodyne interferometer for generating a reference beam to be reflected by a movable mirror unit, and a signal beam to be reflected by an imaging plane in a specimen. The interferometer further generates a first electrical signal output corresponding to first linear polarized waves of the reference and signal beams, and a second electrical signal output corresponding to second linear polarized waves of the reference and signal beams. A differential amplifier receives the first and second electrical signal outputs, and generates a differential signal output therefrom. A data acquisition unit is used to measure amplitudes of the first and second electrical signal outputs and the differential signal output. A computing unit computes the amplitudes measured by the data acquisition unit to determine a reflectivity, a phase retardation, and a fast axis angle of the imaging plane in the specimen.

Abstract: Rotary encoder apparatus is described that comprises one or more readheads and a radial scale. Each of the one or more readheads includes a light emitting portion for illuminating the radial scale and a light detecting portion for detecting interference fringes formed at a readhead analyzer plane. The readhead analyzer plane is tilted relative to the plane containing the radial scale. In a preferred embodiment, the readhead analyzer plane is tilted towards the center of rotation of the rotary encoder apparatus by the angle.

Abstract: A method for step-and-align interference lithography is provided in the present invention, by which a displacement error relating to the moving of an interference light beam as the source of the interference light beam is being carried to move by a carrier is measured before interference lithography, and then the displacement error is used as a reference to compensate a positioning error between adjacent interference patterns during step-and-align interference lithography.

Abstract: A surface shape measurement apparatus is configured to measure a surface shape of an object to be measured, and includes a beam splitter configured to split white light from a light source into two light beams, a pair of prisms each configured to increase an incident angle of each light beam that has been split by the beam splitter and directed to the object or a reference surface, each prism having an antireflection part that is formed at a period of a wavelength of the white light or smaller and has a moth-eye shape, a superimposition unit configured to superimpose object light from the object with reference light from the reference surface and has passed the second prism, and to generate white interference light, and a Lyot filter configured to discretely separate the white interference light for each of a plurality of wavelengths.

Abstract: Provided is a method for focusing a workpiece in the Z-axis for optical metrology. The auto focusing subsystem includes a focus detector having a tilt angle, a capture range, and a plurality of sensors. A processor coupled to the focus detector is configured to utilize the plurality of focus signals measured using the focus detector to determine two or more focus parameters. The two or more focus parameters and calibration data are used to determine an initial position of the workpiece and to generate instructions to move the workpiece to a best focus position.

Abstract: According to an exemplary embodiment, systems and methods can be provided for compensating for, reducing and/or eliminating data associated with at least one aberration provided within a sample. For example, using such exemplary systems and methods, it may be possible to transmit at least one first electromagnetic radiation to the sample via an optical fiber. At least one second electromagnetic radiation can be received from the sample, and the first and second radiations may be associated with one another At least one first intensity of at least one portion of the second radiation within a core of the optical fiber and at least one portion of at least one second intensity of the second radiation within a cladding of the optical fiber at least partially surrounding to the core can be detected. Further, the first radiation and/or the second radiation can be modified as a function of the first and second intensities so as to compensate for, reduce and/or eliminate the data associated with the aberration.

Abstract: Systems configured to generate output corresponding to defects on a specimen and systems configured to generate phase information about defects on a specimen are provided. One system includes an optical subsystem that is configured to create interference between a test beam and a reference beam. The test beam and the reference beam are reflected from the specimen. The system also includes a detector that is configured to generate output representative of the interference between the test and reference beams. The interference increases contrast between the output corresponding to the defects and output corresponding to non-defective portions of the specimen.

Abstract: An apparatus for interferometric sensing, comprising a plurality of single-longitudinal mode laser sources to each provide radiation at a corresponding plurality of selected wavelengths, and at least one modulator to frequency or phase modulate the radiation from each laser; a plurality of Fabry-Perot interferometers formed by Bragg Gratings written into optical fibre, each interferometer being responsive to one of the said plurality of wavelengths to each produce a reflected or transmitted optical output signal dependent on the corresponding interferometer path length; and one or more demodulators to demodulate the optical output signals and produce a corresponding plurality of measurement signals indicative of optical path lengths of the respective interferometers.

Abstract: In the tracking type laser interferometer including: a laser interferometer; an optical axis deviation detection sensor for detecting a deviation of an optical axis of the laser interferometer; a two-axis turning mechanism for turning the laser interferometer to any optional direction; an angle sensor for detecting a turning angle of the two-axis turning mechanism; a retroreflector for reflecting its reflected light to a direction parallel to the incident light; and a controller for driving the two-axis turning mechanism so as to track the retroreflector based on signals of the optical axis deviation detection sensor and the angle sensor, stop of the retroreflector is detected, and a target distance is calculated from the turning center of the laser interferometer to the center of the retroreflector based on the total sum of deviation of an optical axis during movement, which is obtained by the optical axis deviation detection sensor, and a turning angle during movement, which is obtained by the angle sensor.

Abstract: An optical sensor includes at least one optical coupler and an optical waveguide in optical communication with the at least one optical coupler. The optical waveguide is configured to receive a first optical signal from the at least one optical coupler. The first optical signal has a group velocity and a phase velocity while propagating through at least a portion of the optical waveguide, the group velocity less than the phase velocity. An interference between the first optical signal and a second optical signal is affected by perturbations to at least a portion of the optical sensor.

Abstract: The present invention is connected with the holographic interferometry method and device that provides, to a very high precision, the reconstructing the original waveform of light emitted or reflected by an object. This method allows image resolution close to that of the wavelength of the light being used. The non-destructive method of holographic interferometry coupled with impulse heating of the test article to allow observation of its dynamic response to operating conditions, as described herein, is one of the most effective non-contact automated quality control methods available.

Abstract: Methods, systems, and computer program products for performing real-time quadrature projection based FDOCT are disclosed. According to one method, a plurality of interferogram signals is phase shifted. A Fourier transform is applied to each of the plurality of interferogram signals. Depth dependence of the plurality of transformed interferogram signals is then removed. A real quadrature component and an imaginary quadrature component for each of the plurality of transformed interferogram signals are subsequently calculated. The real quadrature components of the transformed interferogram signals are combined to obtain a derived real component and the imaginary quadrature components of the transformed interferogram signals are combined to obtain a derived imaginary component. A full-range depth profile of the object is constructed by adding the derived real component to the product of the derived imaginary component and a scaling factor.

Abstract: In one aspect, the invention relates to a method of acquiring optical coherence tomographic data from a sample. The method includes the steps of scanning a first location on the sample to obtain a first set of optical coherence tomographic data, scanning a second location on the sample to obtain a second set of optical coherence tomographic data, and defining a fiducial position relative to a location on the sample using one of the two sets of optical coherence tomographic data. In one embodiment, the first set of optical coherence tomographic data is survey data. However, in another embodiment the first set of optical coherence tomographic data is sample measurement data.

Abstract: A sensor apparatus and method includes a sensor head with at least two surfaces separated by a gap. One surface is mechanically fixed, a second surface is free to move and deflections of the second surface relative to the first surface are monitored by optical interferometry. In one embodiment, an optical fiber is used to direct light from a light source to the sensor and collect light reflected by the sensor. In alternate embodiments the sensor apparatus includes integrated optical elements, free-space optics, and direct laser-diode sensing. In operation, interaction of molecules or other objects in the sample with the second surface is detected as a change in amplitude and/or phase of deflection the second surface in response to an applied driving signal. A layer of binding molecules may be immobilized on the second surface and this surface exposed to a sample.

Abstract: An interferometer which incorporates a single mode VCSEL to facilitate miniaturization through integration of parts. The interferometer includes a beam splitter for partially reflecting and transmitting light; a single mode vertical-cavity surface-emitting laser for generating a beam of light perpendicular to a wafer; a first mirror fixedly perpendicular to the first path to reflect the portion of light reflected from the beam splitter; a second mirror movably arranged along the second path to reflect the beam portion transmitted through the beam splitter. A photodetector arranged along the second path detects the beam portion reflected from the first mirror and transmitted again through the beam splitter and the beam portion reflected from the second mirror and reflected again from the beam splitter to locate the second mirror based on an interference fringe created by a difference in the paths between the two beam portions.