Multichannel optical coherence systems are disclosed in which optical coherence tomography (OCT) subsystems are operably and respectively connected to optical fibers of a multichannel optical probe, such that each optical fiber forms at least a distal portion of a sample beam path of a respective OCT subsystem. The optical fibers are in optical communication with distal optical elements such that external beam paths associated therewith are directed towards a common spatial region external to the housing. Image processing computer hardware is employed to process OCT signals obtained from the plurality of OCT subsystems to generate an OCT image dataset comprising a plurality of OCT A-scans and process the OCT image dataset to generate volumetric image data based on known positions and orientations of the external beam paths associated with the OCT subsystems.

An apparatus is provided that includes a detector configured to detect, cumulatively during an exposure period, spatially modulated light. The apparatus also includes modulation means for applying multiple different effective spatial modulations to received light, during the exposure period. A different effective spatial modulation is applied to received light in dependence upon a time during the exposure period of the detector and a frequency of the light, to produce spatially modulated light for detection by the detector.

Described herein are an apparatus, system, and method for detecting light. An apparatus can include means for modulating an input beam of light wherein the input beam of light is obtained from an optical coherence tomography arrangement; means for dispersing the modulated beam of light; and means for detecting the dispersed beam of light and converting the detected beam of light into an electrical output signal. An apparatus can include a modulator configured to spatially modulate light; a dispersing element configured to disperse modulated light, and a detector configured to detect dispersed light and convert the detected light into electrical output signals. A method can include spatially modulating a beam of light, dispersing the modulated beam of light, detecting the dispersed beam of light, converting the detecting beam of light into electrical output signals, and providing a three-dimensional image of at least a part of an object.

In some embodiments, systems, methods, and media for multiple reference arm spectral domain optical coherence tomography are provided which, in some embodiments, includes: a sample arm coupled to a light source; a first reference arm having a first path length; a second reference arm having a longer second path length; a first optical coupler that combines light from the sample arm and the first reference arm; a second coupler that combines light from the sample arm and the second reference arm; and an optical switch comprising: a first input port coupled to the first optical coupler; a second input coupled to the second coupler via an optical waveguide that induces a delay at least equal to an acquisition time of an image sensor; and an output coupled to the image sensor.

A height detection apparatus successively changes the brightness of white light from a first level to a second level in accordance with a position of a Z stage and captures an image of interference light while moving a two-beam interference objective lens relative to a paste film in an optical axis direction, detects, as a focus position, a position of the Z stage where the intensity of interference light is highest in a period during which the brightness of white light is set to the first or second level, for each pixel of the captured image, and obtains the height of the paste film based on a detection result.

The present invention relates to an optical coherence tomography analysis method, comprising: Providing a Swept Source Optical Coherence Tomography system (SS-OCT), the SS-OCT system including: a light source, tunable over a spectral band, that generates a coherent light signal; an optical interferometer for dividing the coherent light signal into a reference arm leading to a reference reflector and a sample arm leading to a sample; an optical element to selectively direct a sample light signal exiting the sample arm to a specific portion of the sample, so that for each selection in the optical element a different specific portion of the sample is illuminated; an optical detector for detecting an interference signal generated by a combination of reference and sample returning signals from the reference arm and from the sample arm, reflected by the reference reflector and the sample, respectively; Wherein, for the same selection operated at the optical element level illuminating a specific portion of the sample, the method further comprises: sweeping the light source for a time interval ΔT, so that a wavelength of the coherent light signal, leading to the sample light signal illuminating the specific portion of the sample, changes from a minimum wavelength to a maximum wavelength and wherein the wavelength of the coherent light signal reaches the same value between the minimum wavelength to the maximum wavelength at least twice during the sweeping; detecting the interference signal generated by the sweeping, including the interference signal generated by the sample returning signals of the at least two coherent light signals having the same wavelength; elaborating the detected interference signal generated by the sweeping, including the detected interference signal generated by the sample returning signals of the at least two coherent light signals having the same wavelength, for obtaining an OCT image of the specific portion of the sample.

Shearography systems provide independent setting of fringe frequency and shear magnitude by situating an interferometer with a tiltable reflector proximate a pupil plane of an imaging optical system. Fringe frequency can be selected based on a modified Savart plate. In other examples, a Wollaston prism or a polarization grating is translated with respect to an image sensor to vary shear magnitude while maintaining a substantially fixed fringe frequency.

Systems or apparatuses may include a spatial modulator for spatially modulating light to produce spatially modulated light, a dispersing element for dispersing the modulated light to produce spatially modulated and dispersed light, a polarization-sensitive displacement element for providing a polarization dependent displacement of the dispersed light, and a detector for detecting the spatially modulated, dispersed and displaced light. The system and/or apparatus may include a broadband light source for providing broadband light, a linear polarizer for polarizing the broadband light, a double path interferometer including a sample path via the object and a reference path, a beam splitter for superposing a portion of the light from the sample path and a portion of the light from the reference path to create superposed light for spatial modulation, and/or a processor for processing an output of the detector to produce a three-dimensional image of the object.

Herein disclosed are a surface topography measuring system and a method thereof. The method comprises the following steps: dividing a test beam into a first sub-beam, entering a reflecting mirror along a first axis, and a second sub-beam, entering an object surface along a second axis; moving the reflecting mirror for reflecting the first sub-beam at different positions on the first axis to generate N reflected beams; generating an object reflected beam, related to the second sub-beam, reflected from the object surface; generating N images, related to the N reflected beams and the object reflected beam, and each of the N images having a plurality of interference fringes; analyzing the interference fringes in each of the N images to calculate N curve formulas; calculating a surface topography of the object surface from the N curve formulas.

Methods, apparatus and systems for processing interferograms in metrology applications are described. In one example aspect, a method includes obtaining an input phase image based on the interferograms, segmenting the input phase image by classifying the input phase image into multiple regions based on the phase value and a location of each pixel, assigning an integer value to each of the multiple regions, and constructing an output phase image based on the input phase image and the phase offset of each of the multiple regions.