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: Systems for extended depth frequency domain optical coherence tomography are provided including a detection system configured to sample spectral elements at substantially equal frequency intervals, wherein a spectral width associated with the sampled spectral elements is not greater than one-half of the frequency interval. Related methods are also provided herein.

Abstract: A digitized image of an object may include representations of portions of the object that are obscured, occluded or otherwise unobservable. The image may be a multi-dimensional visual representation of dentition. Characteristics of the dentition and its surfaces, contours, and shape may be determined and/or analyzed. A light may be directed toward and reflected from the dentition. The reflected light may be combined with a reference to determine characteristics of the dentition, including obscured areas such as subgingival tissue.

Abstract: An optical coherence tomography (OCT) apparatus includes: a light source; an OCT optical system including: a first light splitter which splits light emitted from the light source into measurement and reference lights, a second light splitter which splits the measurement light into first and second beams, an optical delay path to generate an optical path length difference between the first and second beams, a scan optical system which scans the respective beams on an object to be examined in a transverse direction, a reference optical system, and a detector which receives a spectrum of composite light in which reflected lights of the first and second beams from the object, and the reference light from the reference optical system are combined; and an arithmetic controller which processes an interference signal output from the detector to obtain first and second tomographic images formed respectively by the first and second beams.

Abstract: Interferometers are provided for measuring the surface shape of an examined object or a transmitted wavefront through the examined object. An exemplary interferometer includes an area light source having a low spatial coherence property, and a light-guiding optical system configured to arrange the area light source and the examined object in an optically conjugate relation with each other.

Abstract: Preferred embodiments of the present invention are directed to systems for phase measurement which address the problem of phase noise using combinations of a number of strategies including, but not limited to, common-path interferometry, phase referencing, active stabilization and differential measurement. Embodiment are directed to optical devices for imaging small biological objects with light. These embodiments can be applied to the fields of, for example, cellular physiology and neuroscience. These preferred embodiments are based on principles of phase measurements and imaging technologies. The scientific motivation for using phase measurements and imaging technologies is derived from, for example, cellular biology at the sub-micron level which can include, without limitation, imaging origins of dysplasia, cellular communication, neuronal transmission and implementation of the genetic code.

Abstract: The present invention improves projection displays of volume data. Using the Minimum Intensity Projection (MinIP), fluid filled regions or other regions of hyporeflective tissue are displayed. By limiting the projection to partial volumes within the volume, differences in the scattering intensity within specific regions are isolated. In this way, hyperreflectivity of weakly scattering tissue can be assessed.

Abstract: The invention relates to a system and to a corresponding method for optical coherence tomography having an interferometer (10) and a detector system (30, 31) which comprises a detector (30) for collecting the light reflected by a specimen (1) to be examined and has a sensitivity to the light reflected by the specimen (1). In order to reduce the times required for the most reliable possible recording of interference signals provision is made such that the sensitivity of the detector system (30, 31) to the light reflected by the specimen (1) and impinging on the detector (30) is modulated with a modulation frequency.

Abstract: An arrangement and a method are provided for robust interferometry for detecting distance, depth, profile, form, undulation, flatness deviation and/or roughness or the optical path length in or on technical or biological objects, including in layered form, or else for optical coherence tomography (OCT), with a source of electromagnetic radiation and with an interferometer, in particular also in the form of an interference microscope, having an object beam path and having a reference beam path, in which an end reflector is arranged, and a line-scan detector for detecting electromagnetic radiation in the form of at least one spatial interferogram.

Abstract: The present invention provides a scatterfield microscopical measuring method and apparatus, which combine scatterfield detecting technology into microscopical device so that the microscopical device is capable of measuring the sample whose dimension is under the limit of optical diffraction. The scatterfield microscopical measuring apparatus is capable of being controlled to focus uniform and collimated light beam on back focal plane of an objective lens disposed above the sample. By changing the position of the focus position on the back focal plane, it is capable of being adjusted to change the incident angle with respect to the sample.

Abstract: A method, apparatus and system for non-invasive imagining and analysis involves generating probe radiation and reference radiation that have orthogonal polarization characteristics and controlling the polarization characteristics such that substantially all the back scattered probe radiation co-propagates with controlled amounts of components of the reference radiation, thereby improving signal to noise ratios and hence performance of imaging and analysis systems. A preferred embodiment of the invention includes a rotational sensitive mirror that systematically rotates the polarization vector of higher order components of the reference radiation.

Abstract: Provided is an optical tomographic imaging apparatus which enables simplification and cost reduction without reducing accuracy when moving part of an object is moved in an optical axis direction of measuring beam. The apparatus using return beam of measuring beam reflected or scattered by an object and reference beam reflected by a reference mirror to image the tomographic image, includes: a reflecting position controlling device for controlling the reflecting position of the reference mirror; a detecting device for a position in a moving part having an optical system for observing the moving part illuminated by an optical system imaging the same on an area sensor based on the Scheimpflug principle and detects position information that the moving part is moved in the direction; and a device for driving the reflecting position controlling device to control the optical path length of the reference beam based on the position information.

Abstract: To remove an artifact generated by coherent noise from a tomographic image, provided is an optical tomographic imaging apparatus including: an artifact acquiring unit for acquiring an artifact generated by interference among a plurality of reflected light beams reflected by a plurality of layers of the object to be inspected; and an acquiring unit for acquiring a second tomographic image of the object to be inspected based on the artifact and a first tomographic image of the object to be inspected.

Abstract: A method includes receiving, at a computational station, photodetection data, originating at a source, encompassing a set of frequency channels and collected at a number of light gathering telescopes. The method also includes determining correlation between the received photodetection data in each frequency channel, and determining a time average of the correlation between the received photodetection data in the each frequency channel. Further, the method includes determining an average over the set of frequency channels to arrive at a mutual coherence magnitude for each pair of the number of light gathering telescopes, and computing imaging data of the source based on the determined mutual coherence magnitude and the correlation between the received photodetection data.

Abstract: The surface shape measuring system includes an illumination unit including a main light source, a focusing lens, and a projection lens; a beam splitter to split illumination light emitted respectively irradiated onto a reference surface and a measurement surface; a light detecting element to capture an interference pattern; and a control computer to obtain surface shape data through white-light interference pattern analysis from an image captured and detect whether or not the measurement surface is defective from the obtained data, wherein a subsidiary light source to provide falling illumination to the target object; and two-dimensional data and three-dimensional data regarding the surface shape of the target object are obtained by selectively intermitting the turning-on of the main light source and the subsidiary light source and the irradiation of the illumination light onto the reference surface.

Abstract: The present invention relates to a method for image calibration and an apparatus for image acquiring. In the method for image calibration, the image formation position for an image acquiring unit of the apparatus is calibrated according to the relative location of the image acquiring unit to a objective lens of the apparatus, wherein the relative location is determined by calculating the focus index of the image acquired by the image acquiring unit so that a clear and sharp interferogram can be obtained for three dimensional surface profile measuring. In addition, it is possible to obtain a clear and sharp image without any interference fringe outside the coherent range by adjusting the image formation position, which is capable of being utilized for two dimensional defect detection and dimension measurement.

Abstract: An optical tomographic diagnostic apparatus is characterized by executing a first step (S1) to acquire a wavelength spectrum, a second step (S2) to increase the number of elements of the wavelength spectrum, a third step (S3 and S4) to convert the wavelength spectrum into a wavenumber spectrum and to decrease the number of elements to provide a wavenumber spectrum of equal intervals, and a fourth step (S5) to acquire tomographic information of the object to be inspected from the wavenumber spectrum. As a result, a wavenumber spectrum of equal intervals can be obtained which is faithful to a physical phenomenon, and more accurate tomographic information can be obtained.

Abstract: An apparatus is provided for measuring a frequency-domain optical coherence tomography power spectrum from a sample. The apparatus includes a partially reflective element configured to be optically coupled to a light source and to the sample. A first portion of light from the light source is configured to be reflected by the partially reflective element. A second portion of light from the light source is configured to propagate through the partially reflective element, to impinge the sample, and to reflect from the sample. The apparatus is configured to receive the first and second portions of light and to measure the frequency-domain optical coherence tomography power spectrum in response to the first portion of light and the second portion of light.

Abstract: A system and method for microscale measurement and imaging of the group refractive index of a sample. The method utilizes a broadband confocal high-numerical aperture microscope embedded into an interferometer and a spectrometric means, whereby spectral interferograms are analyzed to compute optical path delay of the beam traversing the sample as the sample is translated through the focus of an interrogating light beam. A determination of group refractive index may serve to disambiguate phase ambiguity in a measurement of refractive index at a specified wavelength. Spatial resolution of object characterization in three dimensions is achieved by imaging the object from multiple viewpoints.

Abstract: In the optical tomographic imaging apparatus according to an aspect of the present invention, since a stable light intensity can be secured for a reflected light beam of a measurement light beam reflected off of a transmitting surface of a probe outer casing as a returning light beam to an optical fiber, the optical path length difference between a reference light beam and the measurement light beam can be precisely adjusted by adjusting the optical path length of the reference light beam with an optical path length adjusting device. In addition, a signal of a measurement object can be reliably detected from a detection signal of an interference light beam detected by an interference light detecting device.

Abstract: An apparatus for measuring the axial length of a human eye, the apparatus comprising a low coherence light source; a beam splitter; a fast displacement module for rapidly varying the path length within a reference arm of an interferometer; a laser directing a laser beam that is co-propagating with light from the low coherence light source into the displacement module.

Abstract: The invention relates to a system for optical coherence tomography having an interferometer (20), a detector (30) with a first number of detector elements for collecting light, and an optical fiber (29) with a second number of individual fibers for transmitting light from the interferometer (20) to the detector (30). In order to increase the compactness of the system with at the same time high image quality provision is made such that the detector elements have a first center-center distance and the individual fibers have a second center-center distance, the first center-center distance between the detector elements being greater than the second center-center distance between the individual fibers.

Abstract: A microscopy system and method allow observing a fluorescent substance accumulated in a tissue. The tissue can be observed at a same time both with visible light and with fluorescent light. It is possible to observe a series of previously recorded fluorescent light images in superposition with the visible light images. An end of the series of images may be automatically determined. A thermal protective filter may be inserted into a beam path of an illuminating system at such automatically determined end of the series. Further, the fluorescent light image may be analyzed for identifying a coherent fluorescent portion thereof. A representation of a periphery line of the coherent portion may be generated, and depths profile data may be obtained only from the coherent portion. An illuminating light beam for exciting the fluorescence may be modulated for improving a contrast of fluorescent images.

Abstract: Systems, methods, and other embodiments associated with gated optical coherence tomography (OCT) are described. One example method includes generating an image control signal to control an OCT apparatus to acquire an image of an embryonic heart at a specified point in time during a cardiac cycle of the embryonic heart. The method may also include controlling the OCT apparatus to acquire the image based on the image control signal. In different examples, the image may be acquired in vivo or from an excised heart that is paced. The OCT apparatus and the embryonic heart may be housed in an environmental chamber having a set of controllable environmental factors. Therefore, the method may include detecting and controlling the set of controllable environmental factors.

Abstract: A system, process and software arrangement are provided to determine at least one position of at least one portion of a sample. In particular, information associated with the portion of the sample is obtained. Such portion may be associated with an interference signal that includes a first electro-magnetic radiation received from the sample and a second electro-magnetic radiation received from a reference. In addition, depth information and/or lateral information of the portion of the sample, may be obtained. At least one weight function can be applied to the depth information and/or the lateral information so as to generate resulting information. Further, a surface position, a lateral position and/or a depth position of the portion of the sample may be ascertained based on the resulting information.

Abstract: Methods, systems and computer program products are provided for acquiring an image set using optical coherence tomography (OCT). A first portion of a defined volume is scanned at a low-density sampling rate to obtain a plurality of low-density frames. A second portion of the defined volume is scanned at a high-density sampling rate, higher than the low-density sampling rate, to obtain at least one high-density frame. The low-density frames and the at least one high-density frame are combined to provide a complete mixed-density image set.

Abstract: Provided is an optical imaging system based on a coherence frequency domain reflectometry, including: a light source generating an electromagnetic wave; a splitting unit splitting the electromagnetic wave into first and second beams; a reflecting unit reflecting the first beam and re-transmitting the reflected first beam to the splitter; an objective lens projecting the second beam onto an object to be recorded; a photodetector transforming an interference pattern into a current signal, wherein the first beam reflected from the reflector interferes with the second beam reflected from the object to generate the interference pattern; and an electronic processing unit processing the current signal to generate an image of the object from the interference pattern. Therefore, a lateral resolution can be improved, and Rayleigh limits can be overcome.

Abstract: Speckle, a factor reducing image quality in optical coherence tomography (“OCT”), can limit the ability to identify cellular structures that are important for the diagnosis of a variety of diseases. Exemplary embodiments of the present invention can facilitate an implementation of an angular compounding, angular compounding by path length encoding (“ACPE”) for reducing speckle in OCT images. By averaging images obtained at different incident angles, with each image encoded by path length, ACPE maintains high-speed image acquisition and implements minimal modifications to OCT probe optics. ACPE images obtained from tissue phantoms and human skin in vivo demonstrate a qualitative improvement over traditional OCT and an increased signal-to-noise ratio (“SNR”). Accordingly, exemplary embodiments of an apparatus probe catheter and method can be provided for irradiating a structure. In particular, an interferometer may forward forwarding an electromagnetic radiation.

Abstract: In an embodiment of the present invention, an OCT probe is configured by including: a thin and long substantially cylindrical sheath whose distal end is closed; an n-reflecting surface body, as an irradiating device, which has n reflecting surfaces (with n being an integer of three or more) and which is provided in a distal end portion of the sheath; a torque transmitting coil, as a rotating device, which is provided along the longitudinal axis of the sheath and which transmits rotational torque for rotating each of the reflection surfaces of the n-reflecting surface body about the longitudinal axis of the sheath; and n fibers (1) to (n), as an n-channel waveguide device, which are provided and fixed in the sheath in a side by side relationship with the torque transmitting coil.

Abstract: A temperature measurement apparatus includes a light source; a first splitter that splits a light beam into a measurement beam and a reference beam; a reference beam reflector that reflects the reference beam; an optical path length adjustor; a second splitter that splits the reflected reference beam into a first reflected reference beam and a second reflected reference beam; a first photodetector that measures an interference between the first reflected reference beam and a reflected measurement beam obtained by the measurement beam reflected from a target object; a second photodetector that measures an intensity of the second reflected reference beam; and a temperature calculation unit. The temperature calculation unit calculates a location of the interference by subtracting an output signal of the second photodetector from an output signal of the first photodetector, and calculates a temperature of the target object from the calculated location of the interference.

Abstract: A digitized image of an object may include representations of portions of the object that are obscured, occluded or otherwise unobservable. The image may be a multi-dimensional visual representation of dentition. Characteristics of the dentition and its surfaces, contours, and shape may be determined and/or analyzed. A light may be directed toward and reflected from the dentition. The reflected light may be combined with a reference to determine characteristics of the dentition, including obscured areas such as subgingival tissue.

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).

Abstract: A polarization sensitive spectral interferometer apparatus and method for analyzing a sample. The polarization sensitive spectral interferometer apparatus and method determines polarization properties of the sample.

Abstract: In certain aspects, interferometry methods are disclosed that include providing one or more interferometry signals for a test object, wherein the interferometry signals correspond to a sequence of optical path difference (OPD) values which are not all equally spaced from one another because of noise, providing information about the unequal spacing of the sequence of OPD values, decomposing each of the interferometry signals into a contribution from a plurality of basis functions each corresponding to a different frequency and sampled at the unequally spaced OPD values, and using information about the contribution from each of the multiple basis functions to each of the interferometry signals to determine information about the test object.

Abstract: A method of forming an image of tissue. The method includes non-invasively inserting a fiber-based device into a patient's ear canal and acquiring OCT data from ear tissue while the fiber-based device is in the ear canal. The method also includes converting the OCT data into at least one image.

Abstract: An image data set acquired by an optical coherence tomography (OCT) system is corrected for effects due to motion of the sample. A first set of A-scans is acquired within a time short enough to avoid any significant motion of the sample. A second more extensive set of A-scans is acquired over an overlapping region on the sample. Significant sample motion may occur during acquisition of the second set. A-scans from the first set are matched with A-scans from the second set, based on similarity between the longitudinal optical scattering profiles they contain. Such matched pairs of A-scans are likely to correspond to the same region in the sample. Comparison of the OCT scanner coordinates that produced each A-scan in a matching pair, in conjunction with any shift in the longitudinal scattering profiles between the pair of A-scans, reveals the displacement of the sample between acquisition of the first and second A-scans in the pair.

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: An apparatus includes an interferometer configured to generate an interference pattern by combining test light from a test object with reference light reflected from a reference object, the interferometer being further configured to direct at least a first part of a monitor test beam to the test object at a first incident angle and at least a second part of a monitor reference beam to the reference object at a second incident angle, and recombine the first part and the second part of the monitor beams after they reflect from the test and reference surfaces to interfere with one another and form a monitor pattern, where the first and second angles cause the monitor pattern to have spatial interference fringes, and wherein a change in the position of the interference fringes is indicative of a change in a relative position between the test and reference objects.

Abstract: In an OCT apparatus, an object light beam is returned from a target and interferes with a reference light beam. Image information is obtained from a depth Z in the target that depends on the optical path difference between the object and reference beams with a resolution that depends on the coherence length of the light. A scanner transversely scans the target with the object beam over a plurality of image points defined by the resolution of the apparatus. Interface optics directs the reference and object beams onto an array of detector elements such that the optical path difference between the reference beam and the object beam varies across the array. The reference beam and the object beam interfere with each other over the array of detector elements for individual image points on the target during each transverse scan. A memory stores a subset of data points corresponding to each individual image point obtained from each detector elements of the array.

Abstract: An optical coherence tomography device is disclosed for improved imaging. Reduced levels of speckle in the images generated by the device are obtained by forming a B-scan from a plurality of A-scans, wherein each resolution cell of the B-scan is generated through compounding of a subset of the A-scans and wherein at least some of the subset of A-scans are separated by at least half the diameter of a speckle cell both tangent to and orthogonal to the B-scan at that cell.

Abstract: A system, process and software arrangement are provided to determine at least one position of at least one portion of a sample. In particular, information associated with the portion of the sample is obtained. Such portion may be associated with an interference signal that includes a first electromagnetic radiation received from the sample and a second electro-magnetic radiation received from a reference. In addition, depth information and/or lateral information of the portion of the sample, may be obtained. At least one weight function can be applied to the depth information and/or the lateral information so as to generate resulting information. Further, a surface position, a lateral position and/or a depth position of the portion of the sample may be ascertained based on the resulting information.

Abstract: An apparatus for imaging a tooth having a light source with a first spectral range and a second spectral range. A polarizing beamsplitter (18) light having a first polarization state toward the tooth and directs light from the tooth having a second polarization state along a return path toward a sensor (68), wherein the first and second polarization states are orthogonal. A first lens (22) in the return path directs image-bearing light from the tooth, through the polarizing beamsplitter (18), toward the sensor (68), and obtains image data from the redirected portion of the light having the second polarization state. A long-pass filter (15) in the return path attenuates light in the second spectral range. Control logic enables the sensor to obtain either the reflectance image or the fluorescence image.

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 coherence tomography apparatus which acquires a tomogram of a target object based on a light intensity detected for each wavelength by combining return light of measurement light from the target object with reference light corresponding to the measurement light, the apparatus comprising: a normalization unit adapted to normalize the light intensity detected for the each wavelength based on a transfer function corresponding to the wavelength resolution; and an image formation unit adapted to form a tomogram of the target object from the light intensities normalized by the normalization unit.

Abstract: Portable optical coherence tomography (OCT) devices including at least one mirror configured to scan at least two directions are provided. The portable OCT devices are configured to provide a portable interface to a sample that can be aligned to the sample without repositioning the sample. Related systems are also provided.

Abstract: A frequency swept laser source that generates an optical signal that is tuned over a spectral scan band at single discrete wavelengths associated with longitudinal modes of the swept laser source. Laser hopping over discrete single cavity modes allows long laser coherence length even under dynamic very high speed tuning conditions. A ramp drive to the laser is used to linearize laser frequency tuning. A beam splitter is used to divide the optical signal between a reference arm leading to a reference reflector and a sample arm leading to a sample. A detector system detects the optical signal from the reference arm and the sample arm for generating depth profiles and images of the sample.

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

Abstract: A Michelson-interferometer which has two reference arms and a short coherence length is used for the method and apparatus for measurement of geometric values on transparent or diffuse objects (19). The basic optical delay times of the reference arms (11, 12) are chosen in such a manner that they result in an optical delay time difference corresponding to a layer thickness, as a geometric value. The at least two reference arm beams (33a, 35a) are passed to a single rotating path-length variation element (23), with a mutual spatial offset angle (dw). A delay-time change, which is dependent on the rotation angle, of the reference arm beams is produced as a function of a rotation angle caused by rotation, in order to allow a delay-time change caused by the path-length variation element (23) to be applied successively to the basic optical delay times in the reference arms (11, 12).

Abstract: A surgical microscopy system is provided wherein an optical coherence tomography facility is integrated into a microscopy system. A beam of measuring light formed by collimating optics of an OCT system is deflected by a beam scanner, traverses imaging optics, and is reflected by a reflector such that the beam of measuring light traverses an objective lens of microscopy optics and is directed to an object region of the microscopy optics. A position of the beam of measuring light being incident on the reflector is substantially independent on a direction into which the beam of measuring light is deflected by the beam scanner. When traveling through the beam scanner, the beam of measuring light is comprised of a bundle of substantially parallel light rays.

Abstract: A method and a system for Uniform Frequency Sample Clocking to directly sample the OCT signal with a temporally-non-linear sampling clock derived from a k-space wavemeter on the external sample clock input port of a digitizer. The Uniform Frequency Sample Clocking comprises at least one Pathway, which includes characterizing the swept light source, creating a digital representation of the waveform based from the characterization data, and generating a clock signal using a waveform generator to output the clock signal to a digitizer external clock.