Abstract: A spectral-domain magnetomotive optical coherence tomography apparatus, includes (a) a spectral-domain optical coherence tomography device, and (b) a magnet. The magnet is coupled with the optical coherence tomography device so that changes in the magnetic field are coordinated with collection of data by the optical coherence tomography device. This device may be used to examine a sample by spectral-domain magnetomotive optical coherence tomography, which includes examining the sample with a spectral-domain optical coherence tomography device, to collect optical coherence tomography data. The sample contains magnetic particles, and the magnetic particles are subjected to a changing magnetic field during the examining.

Abstract: Methods, fourier domain optical coherence tomography (FDOCT) interferometers and computer program products are provided for removing undesired artifacts in FDOCT systems using continuous phase modulation. A variable phase delay is introduced between a reference arm and a sample arm of an FDOCT interferometer using continuous phase modulation. Two or more spectral interferograms having different phase delay integration times are generated. The spectral interferograms are combined using signal processing to remove the undesired artifacts. Systems and methods for switching between stepped and continuous phase shifting Fourier domain optical coherence tomography (FDOCT) and polarization-sensitive optical coherence tomography (PSOCT) are also provided herein.

Abstract: An OCT technique that permits tomographic observation of biological body parts that are difficult to restrain, and also provides a tomographic observation technique for the observation of a constrainable part that does not require constraint and thus removes a burden on the biological body. A wavelength-tunable light generator (wavelength-tunable light source) is employed as the light source of the optical coherence tomography device. The wavelength-tunable light generator has a wave number tunable range width of at least 4.7×10?2 ?m?1 and an emitted-light frequency width of no more than 13 GHz, for example, and is capable of changing the wave number stepwise at wave number intervals of no more than 3.1×10?4 ?m?1 and time intervals of no more than 530 ?s.

Abstract: An apparatus and method are provided. In particular, at least one first electro-magnetic radiation may be provided to a sample and at least one second electro-magnetic radiation can be provided to a non-reflective reference. A frequency of the first and/or second radiations varies over time. An interference is detected between at least one third radiation associated with the first radiation and at least one fourth radiation associated with the second radiation. Alternatively, the first electro-magnetic radiation and/or second electro-magnetic radiation have a spectrum which changes over time. The spectrum may contain multiple frequencies at a particular time. In addition, it is possible to detect the interference signal between the third radiation and the fourth radiation in a first polarization state. Further, it may be preferable to detect a further interference signal between the third and fourth radiations in a second polarization state which is different from the first polarization state.

Abstract: An optical image measurement device 1 causes an interference light generator to split a low-coherence light into a signal light and a reference light, and superimposes the signal light propagated through a measured object 5000 and the reference light propagated through the reference mirror 9 to generate an interference light. Two-dimensional photosensor arrays 14 and 15 detect the interference light. A computer 16 forms an image of the measured object 5000 based on the detection result. By inserting the optical fiber bundle 5 into the measured object 5000 to perform a measurement, a tomographic image of a deep tissue of the measured object 5000 can be obtained. Furthermore, the optical image measurement device 1 can form a high-resolution image of the deep tissue of the measured object 5000 because performing a measurement using the OCT technology.

Abstract: Polarization sensitive common path OCT/OCR devices are presented. Optical radiation from a source is converted into two cross-polarized replicas propagating therethrough with a predetermined optical path length difference. The two cross-polarized replicas are then delivered to an associated sample by a delivering device, which is, preferably, an optical fiber probe. A combination optical radiation is produced in at least one secondary interferometer by combining a corresponding portion of an optical radiation returning from the associated sample with a reference optical radiation reflected from a tip of an optical fiber of the optical fiber probe. Subject to a preset optical path length difference of the arms of the at least one secondary interferometer, a cross-polarized component, and/or a parallel-polarized component of the combined optical radiation, are selected. The topology of the devices allows for time domain, as well as for frequency domain registration.

Abstract: Systems and methods for digital detection of an analog tomographic signal are described. The methods include receiving an amplitude-modulated analog signal containing tomographic information, the analog signal having a modulation frequency, f?i; and converting the analog signal into a digital signal at a sampling frequency, fs, to produce a number of samples, K. The digital signal is multiplied by an in-phase reference signal to obtain an in-phase signal component, the in-phase reference signal having the frequency, f?i; and the digital signal is multiplied by a quadrature reference signal to obtain a quadrature signal component, the quadrature reference signal having the frequency, f?i. The in-phase signal component and the quadrature signal component are passed through the K-point averaging filter. A signal amplitude is computed based on the filtered in-phase signal component and the filtered quadrature signal component, the signal amplitude being representative of the tomographic information.

Abstract: In general, in one aspect, the invention features apparatus that includes a broadband scanning interferometry system including interferometer optics for combining test light from a test object with reference light from a reference object to form an interference pattern on a detector, wherein the test and reference light are derived from a common light source. The interferometry system further includes a scanning stage configured to scan an optical path difference (OPD) between the test and reference light from the common source to the detector and a detector system including the detector for recording the interference pattern for each of a series of OPD increments, wherein the frequency of each OPD increment defines a frame rate. The interferometer optics are configured to produce at least two monitor interferometry signals each indicative of changes in the OPD as the OPD is scanned, wherein the detector system is further configured to record the monitor interferometry signals.

Abstract: Interferometry system are disclosed that include a detector sub-system including a monitor detector, interferometer optics for combining test light from a test object with primary reference light from a first reference interface and secondary reference light from a second reference interface to form a monitor interference pattern on a monitor detector, wherein the first and second reference interfaces are mechanically fixed with respect to each other and the test light, a scanning stage configured to scan an optical path difference (OPD) between the test light and the primary and secondary reference light to the monitor detector while the detector sub-system records the monitor interference pattern for each of a series of OPD increments, and an electronic processor electronically coupled to the detector sub-system and the scanning stage, the electronic processor being configured to determine information about the OPD increments based on the detected monitor interference pattern.

Abstract: Light from a tissue sample undergoes self-interference on a detector. A low coherence light source may illuminate the sample, and an interferometer receives light from the sample, divides and directs the received light along two paths, phase-delaying one and recombining the beams on a detector to form a signal. A processor coordinated with the phase delay and optionally with spatial scanning or detector array addresses, converts the signal to a tomographic image. Using self-interfering radiation from the sample, rather than interference of a reference source and a return signal, permits imaging with light naturally emitted by the sample, or with wavelength-shifted, delayed or induced light signals, allowing new diagnostic imaging modalities. The processor may create images in registry from different (for example, close but separable) wavelengths. Systems may also operate without an illumination source or may apply other stimuli to evoke emission from the sample.

Abstract: Methods, systems and computer program products for generating parameters for software dispersion compensation in optical coherence tomography (OCT) systems are provided. Raw spectral interferogram data is acquired for a given lateral position on a sample and a given reference reflection. A trial spectral phase corresponding to each wavenumber sample of the acquired spectral interferogram data is postulated. The acquired raw spectral data and the postulated trial spectral phase data are assembled into trial complex spectrum data. Trial A-scan data is computed by performing an inverse Fourier transform on the trial complex spectrum data and determining the magnitude of a result.

Abstract: A device 1 is an OCT device that splits a low-coherence light L0 into a signal light LS and a reference light LR, detects an interference light LC obtained by superimposing the signal light LS propagated through an eye E and the reference light LR propagated through a reference mirror 174, and forms an image of an fundus oculi Ef. The device 1 has a scan unit 141 that scans the eye E with the signal light LS. When a cross-section position is designated in an fundus oculi image Ef?, the device 1 repetitively scans with the signal light LS along each cross-section position to repeatedly forms tomographic images at each cross-section position, thereby displaying a tomographic motion image at each cross-section position on a display 240A. An operator can observe the tomographic motion image to designate the range and timing for measurement of a tomographic still image.

Abstract: The present invention achieves multiplexing spectrum interference optical coherence tomography capable of full-range OCT measurement that causes no delays in measurement time due to high-order scans and is also free from complex conjugated images.

Abstract: A system for and method of processing complex signals encoded into quantum states is presented. According to an embodiment of the invention, polarized components of a pump laser beam are separated and respectively modulated with first and second signals. The modulated polarized components are directed to adjacent non-linear crystals with optical axes aligned at right angles to each-other. Information regarding at least one of the first and second signals is then derived from measurements of coincidence events.

Abstract: A polarization maintaining optical fiber, for guiding a measuring light beam, is provided within a probe. The probe is configured to be rotatable in the circumferential direction of the polarization maintaining optical fiber. A polarization direction rotator, for rotating the polarization direction of the measuring light beam that enters the polarization maintaining optical fiber accompanying rotation of the probe, is provided in order to maintain a state in which the polarization direction of the measuring light beam that enters the polarization maintaining optical fiber and the direction of the polarization axis of the polarization maintaining optical fiber are matched.

Abstract: An optical tomograph which irradiates and scans a measuring light beam onto a measurement target at a predetermined scanning frequency, to obtain a tomographic image of the measurement target is provided. A depolarizing unit, for varying the polarization state of light beams input thereto at a frequency equivalent to or higher than the scanning frequency, such that the light beam output therefrom becomes depolarized when averaged over time, is provided in the optical path of at least one of the measuring light beam, a reference light beam, and a reflected light beam between a light source unit and a combining unit.

Abstract: Three-dimensional shape measuring instrument (white interferometer) for measuring the three-dimensional shape of an object to be measured by using white interference fringes, which detects the position where the amplitude of the white interference fringes takes on a maximum value with high accuracy in a short calculation processing time. An envelope distribution of the amplitude of the white interference fringes produced by the interference between the returning light from a reference mirror (6) and the returning light from an object (7) to be measured is determined, and an approximate position where the contrast of the white interference fringes is the highest is determined using this envelope distribution.

Abstract: A surface emission laser light source is used as a tunable laser light source. Since the surface emission laser light source can realize a broad frequency scanning range at a high speed and in the single mode, a coherent length is longer than that of a multi mode light source. For this reason, when a tomography image is calculated by executing the Fourier transform for an output obtained from an interference optical device, measuring depth can be deepened.

Abstract: Optical coherence tomography (OCT) is an imaging method which can image with micrometer-scale resolution up to a few millimeters deep into, for example, living biological tissues and preserved tissue samples. An improved apparatus and image reconstruction algorithm for parallel Fourier Domain OCT which greatly eases requirements for interferometer stability and also allows for more efficient parallel image acquisition is provided. The apparatuses and algorithms reconstruct images from interfered, low-coherence, multiwave length signals having a ? radian phase difference relative to one another. Other numbers of signals and other phase differences may be alternatively used, with some combinations resulting in higher resolution and image stability. The apparatus also eliminates a need for bulk optics to modulate a phase delay in a reference arm of the optical path. Images may be reconstructed using two spectrometers, where each is coupled to a detector array such as a photodiode array.

Abstract: An apparatus and method for processing an integrated circuit employing optical interference fringes. During processing, light is directed on the integrated circuit and based upon the detection of interference fringes, further processing may be controlled. One implementation involves charged particle beam processing of an integrated circuit as function of detection of interference fringes. A charged particle beam trench milling operation is performed in or on the substrate of an integrated circuit. Light is directed on the floor of the trench. When the floor approaches the underlying circuit structures, some light is reflected from the floor of the trench and some light penetrates the substrate and is reflected off the underlying circuit structures. Interference fringes may be formed from the constructive or destructive interference between the light reflected from the floor and the light from the circuit structures. Processing may be controlled as function of the detection of interference fringes.

Abstract: The present application relates to an optical length measuring apparatus using a laser beam, and has a proposition to enable highly accurate measuring. There includes a length measuring section measuring a distance to a subject and having a measuring laser beam source, a calibration laser beam source emitting a laser beam having a wavelength stability higher than that of a laser beam of the measuring laser beam source, an interference optical system bringing the laser beam of the measuring laser beam source and the laser beam of the calibration laser beam source into interference, and an arithmetic processing section performing a calculation of the distance based on an output of the interference optical system and an output of the length measuring section.

Abstract: An optical tomography system for obtaining a tomographic image of an object to be measured includes a light source unit which emits low coherence light. The low coherence light emitted from the light source unit is divided into measuring light and reference light. The reflected light from the object when the measuring light is projected onto the object and the reference light are multiplexed. The interference light of the reflected light and the reference light which have been multiplexed is detected, and a tomographic image information of the object is obtained by carrying out frequency-analysis on the detected interference light. A first detecting mode in which the interference light is detected at a first wavelength resolution and the interference light is detected at a second wavelength resolution higher than the first wavelength resolution are switched.

Abstract: A system, method, and device for imaging a sample. In embodiments, a light from a low-coherence source or a wavelength-swept source is used to illuminate the sample. Pathlength-resolved intensity profiles of the light reemitted from the sample are recorded and measurements are taken. A reconstruction algorithm is used to invert the pathlength-resolved measurements to form an image.

Abstract: Disclosed is an interferometry analysis method that includes comparing information derivable from multiple interferometry signals corresponding to different surface locations of a test object to information corresponding to multiple models of the test object, wherein the multiple models are parameterized by a series of characteristics that relate to one or more under-resolved lateral features of the test object; and outputting information about the under-resolved surface feature based on the comparison.

Abstract: An optical coherence tomography (OCT) apparatus includes an optical source, an interferometer generating an object beam and a reference beam, a transverse scanner for scanning an object with said object beam, and a processor for generating an OCT image from an OCT signal returned by said interferometer. At least the optical source, the interferometer, and the scanner are mounted on a common translation stage displaceable towards and away from said object. A dynamic focus solution is provided when the scanner and a folded object path are placed on the translation stage.

Abstract: The invention relates to a system for optical coherence tomography having an interferometer (20) which has a beam splitter (24), a reflector (25), an illumination arm (21), a specimen arm (22) and a reference arm (23). In order to increase the compactness of the system with at the same time a high image quality a specimen objective is provided in the specimen arm (22) of the interferometer (20) by means of which light is focussed into a focus lying in or on the specimen (1). Moreover, in the reference arm (23) of the interferometer (20) a reference objective is provided by means of which light is focussed onto the reflector (25). The optical properties of the specimen objective differ from the optical properties of the reference objective.

Abstract: A method for determining a spatial property of an object includes obtaining a scanning low coherence interference signal from a measurement object that includes two or more interfaces. The scanning low coherence interference signal includes two or more overlapping low coherence interference signals, each of which results from a respective interface. Based on the low coherence interference signal, a spatial property of at least one of the interfaces is determined. In some cases, the determination is based on a subset of the low coherence interference signal rather than on the entirety of the signal. Alternatively, or in addition, the determination can be based on a template, which may be indicative of an instrument response of the interferometer used to obtain the low coherence interference signal.

Abstract: In a method of calibrating the pulse energy of a laser device which provides pulsed working laser radiation, by means of the working laser radiation, multiple test ablations, in particular multiple-pulse test ablations, are carried out on one or more test objects, each with different pulse energy. The ablation depth of each of the test ablations is measured, and then, on the basis of the measured ablation depths and a specified setpoint ablation depth, an associated setpoint pulse energy is determined and set on the laser device. According to the invention, the ablation depths are measured by means of a coherent optical interferometric measuring device. The invention also concerns a laser device, in particular to carry out the above method.

Abstract: A superluminescent diode according the present invention employs a uniform AlGaInAs quantum well on an InP substrate, emitting in a range of 1100 to 1800 nm. The favorable conduction band: valence band offset ratio of this material system enables superluminescent diodes which simultaneously provide high power and large optical bandwidth. A recent reduction to practice of the present invention simultaneously demonstrates output power exceeding 100 mW and bandwidth exceeding 100 nm. A preferred embodiment of this invention uses multiple uniform AlGaInAs quantum wells with two confined quantum states and energetic separation in a range of 100-130 nm. An alternate preferred embodiment uses non-uniform wells, with each well having two confined quantum states. The present invention is particularly useful in time domain and spectral domain optical coherence tomography systems, providing increased resolution and tissue penetration for in-vivo imaging.

Abstract: An imaging system uses a low coherence light source to image objects at a relatively far distance (at least 10 cm) and/or of a relatively large size (having a dimension of at least 10 cm). An imaging plane is located such that its image path is substantially equal to a reference path that the light follows within the imaging device. The imaging plane has a thickness of about the coherence length of the light. Only light returning from the imaging plane forms part of the image. Light returning on other paths is effectively negated due to a lack of coherence. The imaging plane may be a fixed distance from the imaging system. Alternatively, the imaging plane may be at a variable distance from the imaging system, with the reference path having a changeable length.

Abstract: A scanning sensor system for noncontact optical scanning of object surfaces having a sensor head (2) and an optics unit (3) as system components matched to one another. The optics unit (3) can be attached and positioned with high precision on the sensor head (2) by means of a fixing device (4). The fixing device (4) has three bearings (20, 21, 22), on which an optics unit (3) pressed against the sensor head (2) is borne and thereby positioned. Each of the three bearings (20, 21, 22) has a pair of bearing parts (17a, 17b; 18a, 18b; 19a, 19b) matched to one another in respect of their shape and positioning, these bearing parts having bearing surfaces in which respectively one of the bearing parts (17a, 18a, 19a) of the bearing part pairs is in contact with at least one bearing surface of the other bearing part (17b, 18b, 19b) of the bearing part pair.

Abstract: A method for sensing a wave-front of specimen light scattered from an illuminated area in a specimen (10) includes the steps of focusing illumination light into the specimen (10), directing specimen light scattered in the specimen (10) to a detector device (50) having a plurality of detector elements (51) and being capable to sense light with local resolution, detecting sample light contained in the specimen light with the detector device (50), said sample light being scattered in a predetermined sample plane (11) of the specimen (10) and being selected by a time-based gating of the specimen light, locally resolved measuring phase information of the sample light, and reconstructing the wave-front of the sample light on the basis of the phase information. Furthermore, a method of microscopic imaging with adapted illumination light is described.

Abstract: An optically reflective or translucent object (14) can be microscopically imaged in all three dimensions and in true color for observation by a human observer. An interferometric optical setup is employed, using the low temporal coherence of a tunable broad-band light source (10, 20) to resolve the axial dimension, a single opto-mechanical or electronic scanning mechanism for accessing different object depths, and a two-dimensional photo sensor device (15, 34) capable of demodulating the temporally or spatially modulated scanning signals to reconstruct the object's full volume. Three volume scans are carried out sequentially, and the tunable broad-band source (10, 20) is operated in such a way that its spectral distribution for each of the volume scans results in an effective system sensitivity corresponding to one of the three CIE (Commission Internationale d'Éclairage) tristimulus curves, or a linear combination thereof.

Abstract: The invention relates to a system and to a corresponding method for optical coherence tomography having an interferometer (10) for emitting light with which a specimen (1) is irradiated, the interferometer (1) comprising a beam splitter (13) and at least one reflector (12) the optical distance (I) of which from the beam splitter (13) is changeable, a specimen objective by means of which light emitted by the interferometer (10) is focussed in a focus lying within the specimen (1), and a detector (30) for collecting light which is reflected by the specimen (1).

Abstract: The invention is directed to a device for determining the thickness, distance and/or profile of areas of a transparent and/or diffuse object that are spaced apart, in particular for measuring distances in the eye. In the device for determining position using an interferometer arrangement based on the Michelson principle, a scanning unit is arranged for the change in path length in the reference beam or measurement beam path. The scanning unit comprises a scan table which is movable translationally in corresponding guides, the movement direction enclosing an angle ? to the reference beam. At least two reference mirrors having a distance d in direction of the reference beam and slightly overlapping laterally are arranged on the scan table so that during the oscillating movement of the scan table carried out by a motor the reference beam is reflected in itself first by the first reference mirror and then by the second reference mirror.

Abstract: The present relates generally to methods, systems and apparatuses for three dimensional and cross-sectional imaging of objects (e.g., silicon) and subjects at a nanometer-scale resolution using short wave-length (e.g., extreme ultra-violet) light.

Abstract: Systems, methods, and apparatuses of low-coherence enhanced backscattering spectroscopy are described within this application. One embodiment includes providing incident light comprising at least one spectral component having low coherence, wherein the incident light is to be illuminated on a target object in vivo. An intensity of one or more of at least one spectral component and at least one angular component of backscattering angle of backscattered light is recorded, wherein the backscattered light is to be backscattered from illumination of the incident light on the target object and wherein the backscattering angle is an angle between incident light propagation direction and backscattered light propagation direction. The intensity of the at least one spectral component and the at least one backscattering angle of backscattered light is analyzed, to obtain one or more optical markers of the backscattered light, toward evaluating said properties.

Abstract: Fourier domain a/LCI (faLCI) system and method which enables in vivo data acquisition at rapid rates using a single scan. Angle-resolved and depth-resolved spectra information is obtained with one scan. The reference arm can remain fixed with respect to the sample due to only one scan required. A reference signal and a reflected sample signal are cross-correlated and dispersed at a multitude of reflected angles off of the sample, thereby representing reflections from a multitude of points on the sample at the same time in parallel. Information about all depths of the sample at each of the multitude of different points on the sample can be obtained with one scan on the order of approximately 40 milliseconds. From the spatial, cross-correlated reference signal, structural (size) information can also be obtained using techniques that allow size information of scatterers to be obtained from angle-resolved data.

Abstract: A method, apparatus and system for optimizing the magnitude of reference levels in non-invasive imaging and analysis is disclosed. Optimizing the magnitude of reference levels enables improving signal to noise ratios and thereby improving the sensitivity and performance of the imaging and analysis system. The invention includes dynamically modifying the magnitude of one or more reference beams and significantly reducing the magnitude of undesirable reference radiation components. It may further include one or more stabilizing feedback systems.

Abstract: A tomographic image measuring method according to the present invention includes a first step of calculating information corresponding to an optical distance of each layer thickness from a wave-number spectrum, a second step of separating and extracting information of each layer from the information corresponding to the optical distance of each layer thickness, a third step of reconverting information of each layer into a wave-number spectrum, respectively, a fourth step of obtaining a interference wave number from the result of the-third step, a fifth step of calculating an order of interference from the interference wave number and the optical distance of each layer; and a sixth step of calculating the optical distance of each layer by making use of the fact that the order of interference is an integer. Thus, when discrete Fourier transform is used, the measuring precision of layers is improved.

Abstract: A film thickness measuring apparatus of the present invention includes: a light source that emits white light to be irradiated onto a multilayer thin film; a spectroscope that disperses reflected light obtained as a result of irradiating the white light onto the multilayer thin film in order to obtain reflectance spectrums; and a computation section, said computation section including: a setting section that sets a plurality of wavelength ranges for the reflectance spectrums; a first conversion section that obtains wavenumber range reflectance spectrums by re-sequencing, among the reflectance spectrums, reflectance spectrums in the plurality of wavelength ranges set in said setting section at equal intervals, respectively; a second conversion section that converts the wavenumber range reflectance spectrums in the plurality of wavelength ranges obtained in said first conversion section into power spectrums, respectively; and a calculation section that obtains a film thickness of the multilayer thin film based

Abstract: An optical coherence tomographic imaging apparatus which has a light intensity varying portion provided on a first optical path for guiding a measuring beam to an object for varying an intensity of the measuring beam; an illumination condition varying portion for varying an illumination condition of the measuring beam that has passed through the light intensity varying portion for the object between a first illumination condition in which a center part of the measuring beam is not blocked and a second illumination condition in which the center part of the measuring beam is blocked; and an image forming portion for weighting a first tomographic image acquired in the first illumination condition and a second tomographic image acquired in the second illumination condition and composing the weighted first second tomographic images to form a third tomographic image.

Abstract: Apparatus, method, logic arrangement and storage medium are provided 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 can be split into N spectral bands. The N spectral bands can be individually detected and processed to provide an increase in the signal-to-noise ratio by a factor of N. Each spectral band may be detected by a separate photo detector and amplified. For each spectral band, the signal can be 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 likely reduced by a factor equal to the number of spectral bands, while the signal amplitude can remain the same.

Abstract: An optical measuring device for measuring a plurality of surfaces of an object to be measured using a system of optical elements. For example, the first surface to be measured can be the inner wall of a narrow guide bore, while the second surface to be measured is formed by a valve-seat section that is conical and positioned at one end of the guide bore. As optical elements of measuring device, at least one beam splitter and one lens system are disposed in such a way that a first portion of the light beams incident on the beam splitter is directed perpendicularly onto the first surface of the object to be measured, and a second portion of the light beams incident on the beam splitter strikes the lens system downstream of the beam splitter and is directed via the lens system perpendicularly onto the second surface.

Abstract: Methods and apparatus for three-dimensional imaging of a sample. A source is provided of a beam of light characterized by partial spatial coherence. The beam is focused onto a sample and scattered light from the sample is superposed with a reference beam derived from the source onto a focal plane detector array to provide an interference signal. A forward scattering model is derived relating measurement data to structure of an object to allow solutions of an inverse scattering problem, based upon the interference signal so that a three-dimensional structure of the same may be inferred. The partial spatial coherence of the source, which may be fixed or variable, may advantageously provide for rejection of multiple scattering artifacts and thus improve image quality.

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: An optical image measurement device comprises: a light source configured to emit a low-coherence light; an interference-light generator configured to generate an interference light, by splitting the low-coherence light into a signal light and a reference light, and superimposing the signal light passed through a measurement object and the reference light passed through a reference object; a changer configured to change a difference in optical path length; a detector configured to detect the interference light; an image forming part configured to form an image of the measurement object within a predetermined frame based on the result of the detection; an analyzer configured to analyze the image, and specify a position of the image within the frame; and a controller configured to control the changer based on the specified position to change the difference so that an image newly formed is placed in a predetermined position within the frame.

Abstract: In general, in one aspect, the invention features a system including a light source, a plurality of interferometers configured to receive light from the light source and to form output light, each interferometer including a first optic and a second optic, the first and second optics configured to be mounted on a first object and a second object, respectively, where first object is moveable with respect to the second object, the first and second optics being configured introduce an optical path length difference (OPD) between two components of the light to form the output light, the OPD being related to the position of the first optic with respect to the second optic.

Abstract: The present invention provides a microstructure device comprising multiple substrates with the components of the device formed on the substrates. In order to maintain uniformity of the gap between the substrates, a plurality of pillars is provided and distributed in the gap so as to prevent decrease of the gap size. The increase of the gap size can be prevented by bonding the pillars to the components of the microstructure. Alternatively, the increase of the gap size can be prevented by maintaining the pressure inside the gap below the pressure under which the microstructure will be in operation. Electrical contact of the substrates on which the micromirrors and electrodes are formed can be made through many ways, such as electrical contact areas, electrical contact pads and electrical contact springs.

Abstract: An exemplary apparatus (100) for measuring eccentricity of an optical module (23) includes a worktable (10), an image sensor device (17), a driving device (13), and a processing device (19). The worktable is configured for supporting the optical module. The image sensor device is configured for receiving an image of the optical module. The driving device is configured for driving rotation of the worktable. The processing device is connected to the image sensor device, and the processing device is configured for analyzing the image of the optical module.