A novel phase generated carrier demodulation method for homodyne interferometers which is robust to modulation depth variations and source intensity fluctuations is provided. By digitally mixing the waveform with a multitone synthetic waveform, distortion becomes negligible even in presence of large variations of modulation depth. The method only requires two mixers and also provides the DC component of the phase in real time, without any previously recorded data or ellipse-fitting algorithms.

An optical complex amplitude measurement apparatus causes a polarization controller to perform control of making a polarized beam of a signal beam having a frequency that is output from a first laser and then passes through a measurement target match with a polarized beam of a reference beam from a second laser. A spatial filter extracts, from the matched signal beam, a plane wave component in which a wave front is distorted due to the passage, and outputs a signal beam having the frequency. The second laser performs a phase synchronization control of a frequency of the reference beam such that a frequency difference due to multiplexing of the signal beam and the reference beam by a homodyne interferometer becomes 0. The controlled reference beam and the signal beam from the polarization controller are multiplexed by a beam splitter.

An optical interference range sensor includes: a light source configured to project a light beam while continuously varying a wavelength thereof using a predetermined sweep frequency pattern; a processing unit configured to measure the distance to a measurement target based on an electrical signal converted by a light-receiving unit; and a storage unit configured to store distance information indicating the measured distance. The predetermined sweep frequency pattern includes a first sweep frequency pattern and a second sweep frequency pattern. The processing unit includes an average distance value calculation unit configured to calculate an average distance value based on the measured distance, first distance information indicating a distance based on a light beam projected using the first sweep frequency pattern, and second distance information indicating a distance based on a light beam projected using the second sweep frequency pattern, of past distance information regarding multiple measurements stored in the storage unit.

An exemplary system, method, and computer-accessible medium for generating an image(s) of an three-dimensional anatomical flow map(s) can include receiving an optical coherence tomography (“OCT”) signal(s), splitting the OCT signal(s) into a plurality of subspectra, averaging the plurality of subspectra, and generating the image(s) of the three-dimensional anatomical flow map(s) based on the averaged subspectra. The OCT signal(s) can be a swept-source OCT signal. The OCT signal(s) can be split into the subspectra based on a Hamming window. The Hamming distance window can be optimized to minimize a nearest side lobe for each of the subspectra. A position of at least one of the subspectra can be shifted prior to averaging the subspectra. The position of all but one of the subspectra can be shifted prior to averaging the subspectra.

An optical measurement instrument includes optical coherence tomography (OCT) interferometer and a pupil retro illumination system which directs laser light onto the retina of an eye via the sample arm of the OCT interferometer. The laser light passes through an intraocular lens (IOL) implanted into the eye, and an iris camera captures an image of the eye from a portion of the light returned from the retina of the eye, the returned light also passing through the IOL. One or more fiducials of the IOL are detected from the captured image, and an angular orientation of the eye is ascertained from the one or more detected fiducials.

A method and related system for measuring a surface of a substrate including at least one structure using low coherence optical interferometry, the method being implemented with a system having an interferometric device, a light source, an imaging sensor, and a processing module, and including: —acquiring, with the imaging sensor, an interferometric signal formed by the interferometric device between a reference beam and a measurement beam reflected by the surface at a plurality of measurement points in a field of view; the following steps being carried out by the processing module: classifying, by a learning technique, the acquired interferometric signals according to a plurality of classes, each class being associated with a reference interferometric signal representative of a typical structure; and analysing the interferometric signals to derive therefrom information on the structure at the measurement points, as a function of the class of each interferometric signal.

A method for validating the placement of pieces in an assembly task by scanning a coherent light source, such as a laser, over a surface and characterizing the detected interference speckle pattern to discriminate the position of the placed piece from the surface on which the piece is placed. This discrimination is possible even if the characteristic features of the piece and background are smaller than the resolution of the scanning system. In addition, characteristics of the piece, such as the orientation of fibers in the material, may be sensed by classification of the associated speckle response.

Methods and systems are provided for using optical interferometry in the context of material modification processes such as surgical laser, sintering, and welding applications. An imaging optical source that produces imaging light. A feedback controller controls at least one processing parameter of the material modification process based on an interferometry output generated using the imaging light. A method of processing interferograms is provided based on homodyne filtering. A method of generating a record of a material modification process using an interferometry output is provided.

A non-confocal point-scan Fourier-domain optical coherence tomography, OCT, imaging system, comprising: a scanning system arranged to perform a two-dimensional point scan of a light beam across an imaging target, and collect light scattered by the imaging target; a light detector arranged to generate a detection signal based on an interference between a reference light and the light collected by the scanning system. The OCT imaging system further comprises hardware arranged to: generate complex volumetric OCT data of the imaging target based on the detection signal, the OCT data including a component which, when the OCT data is processed to generate an enface projection of the OCT data, provides a defocusing and/or distortion in the enface projection; and generate corrected OCT data by executing a correction algorithm which uses phase information in the OCT data to remove at least some of the component from the OCT data.

Disclosed are method and electronic components for: i) electronically extracting a sequence of values from a measurement signal corresponding to a position of a moving object, wherein the sequence of values indicates the position of the moving object at corresponding time increments; ii) electronically determining at least one of an estimate for a velocity of the moving object and an estimate for an acceleration of the moving the object based on a plurality of the values in the sequence of values; and iii) electronically correcting a value in the sequence of values to substantially reduce the effect of processing and signal delays based on one or both of the velocity and acceleration estimates.