G01B9/02044

SYSTEM AND METHOD FOR CORRECTING OPTICAL PATH LENGTH MEASUREMENT ERRORS
20220357146 · 2022-11-10 · ·

A system includes a first optical unit that emits light to a measurement target object and receives first interference light incident from the measurement target object, a second optical unit that emits the light to a reference object configured to have a constant optical path length with respect to a temperature fluctuation and receives second interference light incident from the reference object, a spectroscope connected to the first optical unit and the second optical unit and receives the first interference light and the second interference light to be incident, and a control unit connected to the spectroscope, and the control unit calculates a fluctuation rate of a measurement optical path length with respect to a reference optical path length under a predetermined temperature environment on the basis of the optical path length of the reference object calculated on the basis of the second interference light incident on the spectroscope under the predetermined temperature environment, and the reference optical path length of the reference object acquired in advance, and corrects, on the basis of the fluctuation rate, the optical path length of the measurement target object calculated on the basis of the first interference light incident on the spectroscope under the predetermined temperature environment.

APPARATUS AND METHOD FOR SPECTRAL DOMAIN OPTICAL IMAGING
20230087685 · 2023-03-23 ·

Apparatus and methods are presented for spectral domain optical imaging, in particular for single shot 3-D spectral domain imaging of the retina of the human eye. In certain embodiments one or more 3-D images across elongated areas of an object are acquired, with scanning perpendicular to the long axis of the elongated areas for imaging extended volumes of the object. In preferred embodiments the captured light is sampled in the Fourier plane, in a dimension substantially perpendicular to the long axis, with a cylindrical lenslet array, while in other embodiments the captured light is sampled in the image plane. Apparatus and methods are also presented for hyperspectral imaging of the retina, with the illuminating beams preferably angled to suppress interference from corneal reflections. Apparatus and methods are also presented for multi-wavelength wavefront sensing, with simultaneous capture of light in two or more paths with different delays.

OPTICAL METROLOGY SYSTEM AND METHOD
20230124422 · 2023-04-20 · ·

A measurement system is provided for use in optical metrology measurements. The measurement system comprises a control system which processes raw measured data indicative of spectral interferometric signals measured on a sample in response to illuminating electromagnetic field incident onto a top portion of the sample and comprising at least one spectral range to which said sample is substantially not absorbing. The processing comprises: extracting, from the raw measured data, a portion of spectral interferometric signals describing signal intensity variation with change of optical path difference during interferometric measurements, the extracted signal portion being independent of interferometric signals returned from a bottom portion of the sample in response to said illuminating electromagnetic field; and directly determining, from said extracted portion, both spectral amplitude and phase of reflection of the electromagnetic field from the top portion of the sample, thereby determining measured spectral signature characterizing the SA, SC, SD, SE, SG, SK, SL, ST, SV, SY, TH, TJ, TM, TN, TR, TT, TZ, UA, UG, US, UZ, VC, VN, WS, ZA, ZM, ZW.

DUAL-MODE OPTICAL COHERENCE TOMOGRAPHY AND OPTICAL COHERENCE MICROSCOPY IMAGING SYSTEMS AND METHODS
20220326495 · 2022-10-13 ·

A low-coherence interferometry imaging system for imaging translucent samples, wherein the system includes an optical coherence microscopy (OCM) mode and an optical coherence tomography (OCT) mode, and wherein the system can selectively employ either mode without requiring re-positioning of a sample under test. The system provides for the selective disposition of the OCM mode or the OCT mode in an optical path intermediate a scanning system and an imaging objective.

METHOD AND APPARATUS FOR MAPPING AND RANGING BASED ON COHERENT-TIME COMPARISON
20230160681 · 2023-05-25 · ·

Provided is a system for range detection including at least one beam source arrangement configured to provide illumination of certain coherence length, an optical arrangement, and a detection arrangement including at least one detector unit.

LIGHT-SHEET PHOTONIC-FORCE OPTICAL COHERENCE ELASTOGRAPHY
20230072425 · 2023-03-09 ·

Disclosed are devices and techniques based on optical coherence tomography (OCT) technology in combination with optical actuation. A system for providing optical actuation and optical sensing can include an optical coherence tomography (OCT) device that performs optical imaging of a sample based on optical interferometry from an optical sampling beam interacting with an optical sample and an optical reference beam; an OCT light source to provide an OCT imaging beam into the OCT device which splits the OCT imaging beam into the optical sampling beam and the optical reference beam; and a light source that produces an optical actuation beam that is coupled along with the optical sampling beam to be directed to the sample to actuate particles or structures in the sample so that the optical imaging captures information of the sample under the optical actuation.

OCT DEVICE
20220313078 · 2022-10-06 · ·

An OCT device that selectively captures OCT data of a fundus of a subject eye and OCT data of an anterior segment of the subject eye. The OCT device includes a spectroscopic optical system that spectroscopically detects interference light between reference light and reflection light of measurement light irradiated on the subject eye. The spectroscopic optical system includes a collimating system that collimates the interference light, a spectrally dispersive element that spectrally disperses the collimated interference light for each spectral wavelength, an image formation system that forms an image of the interference light for each spectral wavelength on an imaging surface, and a light receiving element disposed on the imaging surface. An object-side focal length of the collimating system is shorter than an image-side focal length of the image formation system.

Interferometry with pulse broadened diode laser

Various optical systems equipped with diode laser light sources are discussed in the present application. One example system includes a diode laser light source for providing a beam of radiation. The diode laser has a spectral output bandwidth when driven under equilibrium conditions. The system further includes a driver circuit to apply a pulse of drive current to the diode laser. The pulse causes a variation in the output wavelength of the diode laser during the pulse such that the spectral output bandwidth is at least two times larger than the spectral output bandwidth under the equilibrium conditions.

Methods for optical amplified imaging using a two-dimensional spectral brush

An apparatus and method for ultrafast real-time optical imaging that can be used for imaging dynamic events such as microfluidics or laser surgery is provided. The apparatus and methods encode spatial information from a sample into a back reflection of a two-dimensional spectral brush that is generated with a two-dimensional disperser and a light source that is mapped in to the time domain with a temporal disperser. The temporal waveform is preferably captured by an optical detector, converted to an electrical signal that is digitized and processed to provide two dimensional and three dimensional images. The produced signals can be optically or electronically amplified. Detection may be improved with correlation matching against a database in the time domain or the spatial domain. Embodiments for endoscopy, microscopy and simultaneous imaging and laser ablation with a single fiber are illustrated.

SYNCHRONIZING AN OPTICAL COHERENCE TOMOGRAPHY SYSTEM
20230184536 · 2023-06-15 ·

Methods for synchronizing an Optical Coherence Tomography (OCT) system including detection when a plurality of A-line scans obtained from reflected light of a cantilever scanning fiber within a probe oscillating along a scanning path that increases in amplitude over time are no longer being obtained at a point along the oscillating scanning path when the scanning fiber reaches a minimum speed, determining a value by which a phase angle of the oscillating scanning path is out of synchronization with the plurality of A-line scans, and adjusting a trigger clock for the obtaining the plurality of A-line scans based on the value.