Abstract: An apparatus includes an emitter, the emitter comprising an ultraviolet light emitting diode (UV-LED) and being disposed on a first end of a bounded volume suitable for holding a liquid. The liquid may have a negative Langelier saturation index (LSI). The bounded volume can be a chamber, a tank, or the like. The apparatus includes a detector, the detector comprising an ultraviolet light sensor (UV sensor) and being disposed on a second end of the bounded volume, the second end being opposite the first end, wherein the UV-LED comprises a point source, and wherein the emitter generates a parallel beam of light.

Abstract: A spectral analysis device includes a light source, a support body, a linear polarization filter, a detection unit, a regression computation unit, and an absorbance spectrum calculation unit. The support body is fixed such that an incident angle of the light is a predetermined incident angle ?. The linear polarization filter is configured such that lights with polarization angles ?n ranging from 0° to 90° are irradiated to the support body. The detection unit detects a transmitted spectrum S from transmitted lights with the polarization angles ?n. The regression computation unit obtains an in-plane spectrum sip and an out-of-plane spectrum sop through regression analysis by using the transmitted spectrum S and a mixing ratio R. The absorbance spectrum calculation unit calculates an in-plane absorbance spectrum Aip and an out-of-plane absorbance spectrum Aop of the thin film based on the in-plane spectrum and the out-of-plane spectrum.

Abstract: An apparatus and a method for in-line measurement of laser pulses with time-dependent polarization are described, which make possible to carry out in-line measurement of laser pulses whose polarization depends on time. For this, one or more polarization projections are selected: the spectrometer detects the projection on the extraordinary propagation axis of a birefringent system to measure the spectrum in that component, also the projection on the ordinary propagation axis, to measure the spectrum in that component, and finally a projection in an intermediate direction that allows to measure the interference spectrum between the two components. The method allows extracting the temporal evolution of the pulse and its polarization state as a function of time, spectral amplitudes and phases of the various polarization projections of the beam.

Abstract: Systems and methods are provided for determining a presence, type, or amount of an analyte in fluid. An analyte sensor can include a substrate that includes a chiral molecule for sensing the presence of the analyte in the fluid. A property of the chiral molecule may change in response to sensing the presence of the analyte. The change in the property of the chiral molecule can cause a change in polarization of a beam of light traveling through the substrate. The presence, type, or amount of the analyte can be determined based on the change in polarization of the beam of light. The analyte sensor, along with optical fibers, can be used to determine the presence, type, or amount of an analyte in a fluid sample from a wellbore.

Abstract: A hyperspectral imaging system, comprising an input polarizer arranged to receive and polarize a first light, a liquid crystal variable retarder to change a polarization of the first light in a wavelength-dependent manner, an output polarizer arranged to receive the wavelength-dependent polarized first light, a voltage source electrically connected to the liquid crystal variable retarder, a controller connected to the voltage source, the controller configured to control voltages applied to the liquid crystal variable retarder to control a retardance of the first light. A linear image sensor has a length extending in a direction to obtain images of the first light, the linear image sensor synchronized with the controller to collect the images as a function of retardance of the liquid crystal variable retarder after the first light passes through the output polarizer, for generation of an output signal corresponding to a portion of the linear image sensor.

Abstract: In some embodiments, a collection system of a semiconductor metrology tool includes a chuck to support a target from which an optical beam is reflected and an aperture mask to provide an adjustable aperture for the reflected optical beam. The aperture mask includes a plurality of opaque plates with adjustable positions. The collection system also includes a spectrometer to receive the reflected optical beam. The aperture mask is situated between the chuck and the spectrometer along the optical axis.

Abstract: Provided is a microscope system including: an optical fiber in which laser light emitted from a light-source apparatus propagates; a microscope that irradiates a specimen with the laser light propagated in the optical fiber and that obtains an image of the specimen; a mode-scrambling device portion that causes elastic waves to propagate in the optical fiber to form elastic wave interference fringes in the optical fiber; and a control device that controls the driving of the mode-scrambling device.

Abstract: A microscope module, which is cooperated with an image capturing module, includes a housing, a convex lens and an illumination assembly. The housing has a sample inspecting surface located on one side of the housing, which is opposite to the image capturing module. The convex lens is disposed in the housing, and the shortest distance between the sample inspecting surface and the convex lens ranges from 0.1 mm to 3.0 mm. The illumination assembly has a light source and is located between the image capturing module and the convex lens. The light emitted from the light source enters the convex lens through an input surface of the convex lens, leaves the convex lens through an output surface of the convex lens, and then reaches the sample inspecting surface. A microscope device containing the microscope module is also disclosed.

Abstract: A frequency resolved optical gating (FROG) system receives an ultrafast laser pulse as the “unknown wave” input to the system. The FROG system preferably generates a spectrogram (FROG trace) of the input pulse using a polarization gate, second harmonic generation or other FROG geometry. The system or method preferably analyzes the spectrogram using constrained outer products and principal component generalized projections to find characteristics of the unknown wave such as intensity and phase. Examples of constrained outer products include outer products that incorporate an external constraint such as spectral information or an internal constraint such as a relationship between the probe and gate components derived from the unknown wave.

Abstract: An optical sensor includes a flow cell permitting flow of a hydrocarbon-based analyte therethrough. A metallic film is disposed adjacent or within the flow cell. At least one optical element directs polychromatic light for supply to an interface of the metallic film under conditions of surface plasmon resonance (SPR) and directs polychromatic light reflected at the interface of the metallic film (which is sensitive to SPR at such interface and thus provides an SPR sensing region within the flow cell) for output to at least one spectrometer that measures spectral data of such polychromatic light. A computer processing system is configured to process the measured spectral data over time as the hydrocarbon-based analyte flows through the flow cell to determine SPR peak wavelength over time and to process the SPR peak wavelength over time to determine at least one property related to phase transition of the analyte.

Abstract: Generally, in accordance with the various illustrative embodiments disclosed herein, a homodyne optical interferometer can include a multi-phase beam combining system that receives a composite beam from an optical beam guidance system and uses a diffraction grating to produce a diffracted plurality of light beam members. Each of the diffracted plurality of light beam members is propagated through a birefringent optical element that imposes a differential phase shift on each member based on polarization and differing optical path lengths. In one example implementation, the birefringent optical element can be a parallel plate optical element arranged at an angle with respect to a light-propagation axis of the multi-phase beam combining system and in a second example implementation, the birefringent optical element can be a multifaceted optical element having a first planar external surface that is sloped with respect to an opposing external planar surface.

Abstract: A spectrometer includes a beam splitter that receives incident light rays and splits each of the incident light rays into first and second spatially displaced, linearly polarized light rays that respectively have first and second polarization directions orthogonal to each other; an optical member that receives the split incident light rays from the beam splitter and optically converts the split incident light rays into a plurality of light beams that are respectively guided to mutually differing locations so as to generate interference fringes in the respective locations, each of the plurality of light beams including a component of the first linearly polarized light rays and a component of the second linearly polarized light rays; and a detector that detects the interference fringes respectively generated by the plurality of light beams.

Abstract: Provided are a transparent conductive film having a simple manufacturing process and high transparency, high photoelectric conversion efficiency, and excellent durability and an organic photoelectric conversion element using this transparent conductive film. The transparent conductive film of the present invention is formed by laminating a ground layer which contains a nitrogen-containing organic compound and a metal thin film layer which contains a metal element of Group 11 of the periodic table and has a thickness of from 2 to 10 nm.

Abstract: Polarization based channeled images are optically demodulated to produce directly viewable images. A channeled image flux is converted to an unpolarized flux by a phosphor or other sensor, and the resulting converted flux is demodulated by modulating at a spatial frequency corresponding to a modulating frequency of the channeled image flux. After modulation, the converted flux is spatially filtered to remove or attenuate portions associated with the modulation frequency and harmonics thereof. The resulting baseband flux is then imaged by direct viewing, projection, or using an image sensor and a display.

Abstract: An interferometer comprises: a light source; a first polarization beam splitter configured to reflect, as reference light, a first polarization component of light emitted from the light source, and to transmit, as measurement light, a second polarization component of the light emitted from the light source; a birefringent-material element located between the light source and the first polarization beam splitter; and a light-receiving device configured to receive an interfering light generated by interference of the measurement light transmitted through the first polarization beam splitter, reflected by a reflecting surface to be measured, and transmitted through the first polarization beam splitter, with the reference light reflected by the first polarization beam splitter. The interferometer is configured such that the reference light and the measurement light pass through the birefringent-material element between the first polarization beam splitter and the light-receiving device.

Abstract: An apparatus is disclosed for filtering of probe light and measurement of probe light frequency. The apparatus includes an optical filter comprised of a medium of rapidly changing circular birefringence. The circular birefringent medium changes the polarization of probe light such that light within a certain frequency bandwidth is rotated between crossed polarizers so it will be transmitted through the second polarizer. The spectrometer rotates the polarization of probe light an amount that is dependent upon probe light frequency. Probe light frequency is deduced by analyzing probe light polarization after it propagates through the birefringent medium. The birefringent medium is constructed from a gaseous substance and a magnetic field, where the gaseous substance has one or more absorption lines near the probe light frequency. The magnetic field permeates the gaseous substance and shifts the frequency of the absorption line(s) by the Zeeman effect.

Abstract: A highly efficient vacuum ultraviolet circular dichroism spectrometer is provided; the spectrometer suitable for laboratory use or for integration into a beam line at a synchrotron radiation facility. In one embodiment, a spectroscopic circular dichroism instrument is provided; the instrument configured so as to enable circular dichroism data to be simultaneously obtained for multiple wavelengths of light. The instrument may be further configured to operate in at least a portion of the vacuum ultraviolet wavelength region.

Abstract: An imaging interferometric transform spectropolarimeter configured to simultaneously collect four polarizations. In one example, an spectropolarimeter includes a dual-beam interferometric transform spectrometer configured to receive electromagnetic radiation from a viewed scene, and including first and second focal plane arrays that are spatially registered with one another, a first polarizer coupled to the first focal plane array and configured to transmit only a first pair of polarizations to the first focal plane array, and a second polarizer coupled to the second focal plane array and configured to transmit only a second pair of polarizations to the second focal plane array, the second pair of polarizations being different than the first pair of polarizations.

Abstract: A phase-locked delay device, including: an input port configured to receive an input electromagnetic radiation pulse; said input pulse being to be propagated along a propagation direction and having a first linear polarization different from both a first direction, which is orthogonal to the propagation direction, and a second direction, which is orthogonal to the first direction and the propagation direction; an adjustable Babinet-Soleil module optically coupled to said input port, having a first polarization direction parallel to said first direction. The adjustable Babinet-Soleil module is structured to: provide from the input pulse a first pulse polarized along the first direction and a second pulse collinear to said first pulse and polarized along the second direction, and introduce an adjustable group delay between the first pulse and the second pulse ranging from a minim value ?Tm and a maximum value ?TM; the maximum value ?TM being a value greater than 10 fs.

Abstract: A method and apparatus is disclosed for measurement of probe light frequency. The apparatus includes an optical spectrometer comprised of a medium of rapidly changing circular birefringence. The circular birefringent medium changes the polarization of probe light an amount that is dependent upon probe light frequency. Thus probe light frequency is deduced by analyzing probe light polarization after it propagates through the birefringent medium. The birefringent medium is constructed from a gaseous substance and a magnetic field, where the gaseous substance has one or more absorption lines near the probe light frequency. The magnetic field permeates the gaseous substance and shifts the frequency of the absorption line(s) by the Zeeman effect. The method includes probe light emitted from a transmitter, which scatters off of a target, then the scattered probe light is collected and transmitted through the optical spectrometer where frequency is measured.

Abstract: A system for performing optical spectroscopy measurements includes a light source for generating an input optical beam and an interferometer. The interferometer includes a beam splitter that splits the input optical beam into first and second light beams; a first light path that directs the first light beam through a sample containing an analyte to a first output port; and a second light path that directs the second light beam to the first output port. At least one of the first and second light paths adjusts a relative phase of a corresponding one of the first and second light beams, so that the first and second light beams are out of phase at the first output port, substantially canceling background light and outputting sample light corresponding to a portion of the first light signal absorbed by the sample in the sample cell. A detection system detects the output sample light.

Abstract: Various systems and methods for performing optical analysis downhole with an interferogram (a light beam having frequency components with a time variation that identifies those frequency components. The interferogram is produced by introducing an interferometer into the light path, with the two arms of the interferometer having a propagation time difference that varies as a function of time. Before or after the interferometer, the light encounters a material to be analyzed, such as a fluid sample from the formation, a borehole fluid sample, a core sample, or a portion of the borehole wall. The spectral characteristics of the material are imprinted on the light beam and can be readily analyzed by processing electronics that perform a Fourier Transform to obtain the spectrum or that enable a comparison with one or more templates. An interferometer designed to perform well in the hostile environments downhole is expected to enable laboratory-quality measurements.

Abstract: The present invention is related to a Fourier-transform spectrometer arrangement comprising a first polarizer, a birefringent plate, a pair of birefringent wedges, a second polarizer, a photo detector, and a control unit. According to the invention, the cross sections of the two birefringent wedges of the birefringent wedge pair are similar triangles, the first wedge is fixed, the second wedge is capable of linearly movement along the side, the optic axes of the pair of birefringent wedges are parallel to each other and orthogonal to the optic axis of the birefringent plate, the polarization of the first polarizer is in 45 degrees with the optical axis of the birefringent plate, the polarization of the first polarizer is also in 45 degrees with the optical axis of the pair of birefringent wedges, the polarization of the second polarizer is parallel, or orthogonal, to the polarization of the first polarizer.

Abstract: A spectral measurement device includes: an optical band-pass filter section that has first to n-th wavelengths (n is an integer of 2 or more) having a predetermined wavelength width as a spectral band thereof; a correction operation section that corrects a reception signal based on an output optical signal from the optical band-pass filter section; and a signal processing section that executes predetermined signal processing based on the reception signal corrected by the correction operation section that corrects the reception signal based on the change in the spectral distribution of the reception signal.

Abstract: An apparatus and method to determine a property of a substrate by measuring, in the pupil plane of a high numerical aperture lens, an angle-resolved spectrum as a result of radiation being reflected off the substrate. The property may be angle and wavelength dependent and may include the intensity of TM- and TE-polarized radiation and their relative phase difference.

Abstract: In one embodiment, an element 106 transforms non-polarized light into plane polarized light with an arbitrary plane of polarization. A synchronizer 112 gives the element 106 an instruction to rotate the plane of polarization, thereby getting the plane of polarization of the illumination rotated and casting that polarized illumination toward the object. At the same time, the synchronizer 112 sends a shooting start signal to an image sensor 110, thereby getting video. The synchronizer 112 performs these processing steps multiple times. A captured video signal is sent to an image processing processor 108. Candidates for the azimuth angle of a surface normal are obtained based on an intensity maximizing angle image, the zenith angle of the surface normal is obtained based on a degree of intensity modulation image, and the ambiguity of the azimuth angle is solved, thereby generating a surface groove normal image.

Abstract: A method for compensating for errors in a spectrometer is provided that includes measuring at least a portion of a path length for a signal traveling through the spectrometer during a measurement scan of a material. A detector signal corresponding to the measurement scan is generated. Compensation for errors in the detector signal is provided based on the measurement of the path length.

Abstract: A phase-locked delay device, including: an input port configured to receive an input electromagnetic radiation pulse; said input pulse being to be propagated along a propagation direction and having a first linear polarization different from both a first direction, which is orthogonal to the propagation direction, and a second direction, which is orthogonal to the first direction and the propagation direction; an adjustable Babinet-Soleil module optically coupled to said input port, having a first polarization direction parallel to said first direction. The adjustable Babinet-Soleil module is structured to: provide from the input pulse a first pulse polarized along the first direction and a second pulse collinear to said first pulse and polarized along the second direction, and introduce an adjustable group delay between the first pulse and the second pulse ranging from a minim value ?Tm and a maximum value ?TM; the maximum value ?TM being a value greater than 10 fs.

Abstract: An apparatus for phase detection of Raman scattered light emitted from a sample includes a first polarizer positioned along a first optical path containing a first beam and a second polarizer positioned along a second optical path containing a second beam. The first polarizer and second polarizer polarize the first beam and the second beam in one of mutually perpendicular and mutually parallel first and second directions. The apparatus also includes an optical phase modulator positioned along the second optical path to controllably modulate a phase of the second beam, a beam splitter positioned to join the first beam and the second beam together, and a spectrometer to receive the joined first beam and second beam and to measure a phase shift of the first beam and the second beam.

Abstract: An apparatus and method to determine a property of a substrate by measuring, in the pupil plane of a high numerical aperture lens, an angle-resolved spectrum as a result of radiation being reflected off the substrate. The property may be angle and wavelength dependent and may include the intensity of TM- and TE-polarized radiation and their relative phase difference.

Abstract: Provided is a chromatic dispersion measurement device including a light branching unit that divides a incident measured light signal into a first measured light signal and a second measured light signal and causes a frequency difference between the first measured light signal and the second measured light signal when the signals are output, an optical phase shifter provided in either one of the first branch path and the second branch path having a polarization maintaining characteristic and periodically changing a phase ?i of the measured light signal, an optical combination unit that combines the first measured light signal and the second measured light signal and outputs an interference element of an i-th optical component obtained by interference of the first measured light signal and the second measured light signal when the phase difference is the phase ?i, as a combined measured light signal.

Abstract: A spectrum detecting device including a laser apparatus, an optical splitting apparatus, an optical gate, a first polarizer, a second polarizer, and an optical analysis apparatus is provided. The optical splitting apparatus splits the laser beam providing from the laser apparatus into a first and a second light beam, and the second light beam is transmitted to a sample to produce a spectral signal. The optical gate activated by the first light beam is disposed between the optical analysis apparatus and the sample. The first polarizer is disposed between the sample and the optical gate, and the second polarizer is disposed between the optical gate and the optical analysis apparatus. The spectral signal passes through the first polarizer, the optical gate, and the second polarizer to be transmitted and received to the optical analysis apparatus when the optical gate is activated and turned on in a predetermined time period.

Abstract: An interference measuring apparatus comprises a light source module, a beam splitter, a first lens module, a reflecting module, a second lens module, and a detection device. A light beam generated from the light source module can be projected on the beam splitter. The beam splitter splits the light beam to generate a first light beam and a second light beam. The first light beam passes through the first lens module and then projects onto the reflecting module, and the second light beam passes through the second lens module and projects onto an object. Furthermore, the first light beam and the second light beam are reflected by the reflecting module and the object, respectively, then both the first light beam and the second light beam are leaded to the detection device to form an interference pattern for obtaining the contours and internal cross-sectional image of the object.

Abstract: Snapshot imaging Fourier transform spectrometers include a lens array that produces sub-images that are directed through a birefringent interferometer in orthogonal polarization eigenstates that acquire an optical path difference. Interference patterns based on this OPD can be Fourier transformed to obtain a spectral image. In some examples, polarizing gratings provide a spatial heterodyne frequency and offset the spectra.

Abstract: An optical coherence tomography (OCT) imaging system is disclosed. In an embodiment of the invention, an OCT imaging system may include (a) multiple scan geometries, including a lateral scan of a beam perpendicular to the scan direction and a rotating scan where the beam is perpendicular to a curved surface (such as the front of the eye), and (b) a low coherence interferometry engine based on spectral domain interferometry, with a spectrometer capable of ultra deep imaging.

Abstract: Disclosed is a system and method for characterizing optical materials, using steps and equipment for generating a coherent laser light, filtering the light to remove high order spatial components, collecting the filtered light and forming a parallel light beam, splitting the parallel beam into a first direction and a second direction wherein the parallel beam travelling in the second direction travels toward the material sample so that the parallel beam passes through the sample, applying various physical quantities to the sample, reflecting the beam travelling in the first direction to produce a first reflected beam, reflecting the beam that passes through the sample to produce a second reflected beam that travels back through the sample, combining the second reflected beam after it travels back though the sample with the first reflected beam, sensing the light beam produced by combining the first and second reflected beams, and processing the sensed beam to determine sample characteristics and properties.

Abstract: There is disclosed a phase sensitive surface plasmon resonance sensing apparatus wherein a testing beam may be reflected from a sensing surface at a plurality of angles. There are also disclosed methods for surface plasmon resonance sensing.

Abstract: There is provided a method for analyzing optical properties of an object, including utilizing a light illumination having a plurality of amplitudes, phases and polarizations of a plurality of wavelengths impinging from the object, obtaining modified illuminations corresponding to the light illumination, applying a modification to the light illumination thereby obtaining a modified light illumination, analyzing the modified light illumination, obtaining a plurality of amplitudes, phases and polarizations maps of the plurality of wavelengths, and employing the plurality of amplitudes, phases and polarizations maps for obtaining output representing the object's optical properties. An apparatus for analyzing optical properties of an object is also provided.

Abstract: Designs, implementations, and techniques for optically measuring a sample and integrated systems that provide CT-scan, optical probing and therapy by electromagnetic radiation treatment (e.g. laser, RF, or microwave). Light at different wavelength bands may be used to detect different absorption features in the sample. Multiple light sources may be used including tunable lasers.

Abstract: An interferometric system for measuring surfaces of a measured object using an optical system. The optical system has a beam splitter, which directs measuring beams in a first beam path and measuring beams in a second beam path onto the surfaces of the measured object with the aid of two mirrors. The beam paths which are formed by the light beams which are reflected on the surfaces at least partially overlap in an area having identical beam direction. In this manner, measured surfaces of the measured object are at least partially imaged on an identically irradiated surface of a detector, such as an image recorder.

Abstract: Systems and methods for obtaining information on a key in the BB84 (Bennett-Brassard 1984) protocol of quantum key distribution are provided. A representative system comprises a quantum cryptographic entangling probe, comprising a single-photon source configured to produce a probe photon, a polarization filter configured to determine an initial probe photon polarization state for a set error rate induced by the quantum cryptographic entangling probe, a quantum controlled-NOT (CNOT) gate configured to provide entanglement of a signal with the probe photon polarization state and produce a gated probe photon so as to obtain information on a key, a Wollaston prism configured to separate the gated probe photon with polarization correlated to a signal measured by a receiver, and two single-photon photodetectors configured to measure the polarization state of the gated probe photon.

Abstract: Systems and methods for using common-path interferometric imaging for defect detection and classification are described. An illumination source generates and directs coherent light toward the sample. An optical imaging system collects light reflected or transmitted from the sample including a scattered component and a specular component that is predominantly undiffracted by the sample. A variable phase controlling system is used to adjust the relative phase of the scattered component and the specular component so as to change the way they interfere at the image plane. The resultant signal is compared to a reference signal for the same location on the sample and a difference above threshold is considered to be a defect. The process is repeated multiple times each with a different relative phase shift and each defect location and the difference signals are stored in memory. This data is then used to calculate an amplitude and phase for each defect, which can be used for defect detection and classification.

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: 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 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: Measuring of an electro-optic coefficient and a thermo-optic coefficient of an optical device and an optical material, and more specifically, to measurement systems and methods of evaluating the electro-optic and thermo-optic coefficients by using interference fringe measurement techniques, wherein those optical characteristics can be precisely measured over a wide wavelength intended without using a complicated measuring equipment.

Abstract: A method and apparatus for extracting the vector optical properties of biological samples with micron-scale resolution in three dimensions, using polarization-sensitive optical coherence tomography (PS-OCT). The method measures net retardance, net fast axis, and reflectivity. Polarization sensing is accomplished by illuminating the sample with at least three separate polarization states, using consecutive acquisitions of the same pixel, A-scan, or B-scan. The method can be implemented using non-polarization-maintaining fiber and a single detector. This PS-OCT method reported measures fast axis explicitly. In a calibration test of the system, net retardance was measured with an average error of 7.5° (standard deviation 2.2°) over the retardance range 0° to 180°, and fast axis with average error of 4.8° over the range 0° to 180°.

Abstract: A tunable spectral filtration device is disclosed that includes one or more pairs of interference filters in series, wherein each element of each pair is independently selected from one or more options, independently positioned to intersect a path of converging or diverging light, and independently tilted with respect to the light path. Each filter may be either of a bandpass type, a shortpass type, a longpass type, a notch type, or multiple combinations thereof. Each filter in the series may be independently selected and tilted to tune the net spectral output of the series. The elements in a pair of filters may be tilted in opposite directions so as to cancel angle-of incidence dependent broadening of the spectral output of the individual filters for noncollimated light, as well as cancel translational shift of the transmitted light rays.

Abstract: An Electro-Optic Imaging Fourier Transform Spectrometer (EOIFTS) for Hyperspectral Imaging is described. The EOIFTS includes an input polarizer, an output polarizer, and a plurality of birefringent phase elements. The relative orientations of the polarizers and birefringent phase elements can be changed mechanically or via a controller, using ferroelectric liquid crystals, to substantially measure the spectral Fourier components of light propagating through the EIOFTS. When achromatic switches are used as an integral part of the birefringent phase elements, the EIOFTS becomes suitable for broadband applications, with over 1 micron infrared bandwidth.

Abstract: An optical absorption spectrometer is provided for determining the concentration of a substance within a sample. The optical absorption spectrometer comprises a first radiation source for supplying radiation to the sample to be measured; at least one cavity for containing the sample during measurement; and a detector assembly for detecting radiation transmitted along first and second optical paths through the sample, the length of the first optical path being greater than that of the second optical path.