G01B9/02044

Optical coherence tomography apparatus and image generation method using the same

An optical coherence tomography (OCT) apparatus includes a light source unit to generate light, a coupler unit to generate coupled light using reference light and measurement light generated by splitting the light, split the coupled light into n coupled and split lights and irradiate the n coupled and split lights, wherein n is a natural number greater than or equal to 2, a detection unit to irradiate the incident n coupled and split lights to n spectroscopes respectively and sequentially scan each light separated from each of the spectroscopes by wavelength range, and an image generation unit to generate a 2-dimensional single image using a result of the scanning by the detection unit. Accordingly, it is possible to improve the OCT image acquisition rate by distributing the scan time for a plurality of split lights using a plurality of array detectors.

VIBRATION INSENSITIVE INTERFEROMETRY FOR MEASURING THICKNESS AND PROFILE OF MULTILAYER THIN-FILM

The present disclosure relates to an apparatus and a method for a thickness and a profile of a multilayer thin film using a vibration insensitive interference method are provided, which allow measuring the phase of a measurement object by acquiring a plurality of different phase-shifted interference signal images at a time through interference signals between a reference flat and the measurement object by a polarizing beam splitter, a quarter-wave plate, a shutter and a pixelated polarizing camera, and which also allow measuring reflectance of the measurement object by acquiring a plurality of reflected signal images obtained at a time through respective reflected lights for each of a reference surface and the measurement object by a plurality of different polarizers.

SYSTEMS AND METHODS FOR ENDOSCOPIC ANGLE-RESOLVED LOW COHERENCE INTERFEROMETRY
20180008147 · 2018-01-11 ·

A method of assessing tissue health comprises the steps of obtaining depth-resolved spectra of a selected area of in vivo tissue, and assessing the health of the selected area based on the depth-resolved structural information of the scatterers. Obtaining depth-resolved spectra of the selected area comprises directing a sample beam towards the selected area at an angle, and receiving an angle-resolved scattered sample beam. The angle-resolved scattered sample beam is cross-correlated with the reference beam to produce an angle-resolved cross-correlated signal about the selected area, which is spectrally dispersed to yield an angle-resolved, spectrally-resolved cross-correlation profile having depth-resolved information about the selected area. The angle-resolved, spectrally-resolved cross-correlation profile is processed to obtain depth-resolved information about scatterers in the selected area.

Chip-scale optical coherence tomography engine

An optical coherence tomography (OCT) engine includes a digital Fourier-Transform (dFT) spectrometer, a tunable delay line, and a high-speed optical phased array (OPA) scanner integrated onto a single chip. The broadband dFT spectrometer offers superior signal-to-noise ratio (SNR) and fine axial resolution; the tunable delay line ensures large imaging depth by circumventing sensitivity roll-off; and the OPA can scan the beams at GHz rates without moving parts. Unlike conventional spectrometers, the dFT spectrometer employs an optical switch network to retrieve spectral information in an exponentially scaling fashion—its performance doubles with every new optical switch added to the network. Moreover, it also benefits from the Fellgett's advantage, which provide a significant SNR edge over conventional spectrometers. The tunable delay line balances the path length difference between the reference and sample arms, avoiding any need to sample high-frequency spectral fringes.

Heterodyne photonic integrated circuit for absolute metrology
11703317 · 2023-07-18 · ·

A digital measuring device implemented on a photonic integrated circuit, the digital measuring device including a laser source configured to provide light, a first ring resonator configured to produce a first frequency comb of light from the laser source, wherein at least a portion of the first frequency comb of light is directed at a moving object, a local oscillator configured to provide a reference beam, at least one waveguide structure configured to combine the reference beam with light reflected from the moving object to produce a measurement beam, a first multiplexer configured to split the measurement beam into a plurality of channels spaced in frequency, and a plurality of detectors configured to detect an intensity value of each channel of the plurality of channels to measure a distance between the digital measuring device and the moving object.

TOMOGRAPHIC IMAGING SYSTEM FOR TRANSPARENT MATERIAL COMPOSITE THIN FILM

A tomographic imaging system includes a light source, a light irradiation unit that irradiates light to a transparent material composite thin film sample and a reference mirror and acquires an interference signal between light reflected and scattered from the sample and light reflected from the reference mirror, a light measuring unit that measures the interference signal acquired by the light irradiation unit, a light transmission unit that transmits the light output from the light source to the light irradiation unit and transmits the interference signal of the light transmitted from the light irradiation unit to the light measuring unit; and a signal processing apparatus that converts the interference signal of the sample, outputs the converted interference signal as a tomographic image, and monitors the interference signal acquired by the light irradiation unit to modulate intensity and a polarization state of the light input to the light irradiation unit.

Optical coherence tomographic apparatus and optical coherence tomographic method performing spectrum conversion based on single gaussian distribution curve
11525665 · 2022-12-13 · ·

To optimize an imaging range in a depth direction in terms of a relationship with a resolution, an OCT apparatus includes a signal processor that determines a reflected light intensity distribution of an imaging object on the basis of a spectrum of a detected interference light. The signal processor performs spectrum conversion, having a conversion characteristic with which a light source spectrum is converted to a Gaussian distribution curve, on the spectrum of the interference light, and determines the reflected light intensity distribution by Fourier-transforming a spectrum resulting from the spectrum conversion. In the conversion characteristic, the light source spectrum and the Gaussian distribution curve have center wavelengths differing from each other.

Spectral contrast optical coherence tomography angiography

In an aspect, a method for imaging a target comprises steps of: performing optical coherence tomography (OCT) scanning on the target with one or more beams of source light, the one or more beams of source light comprising a plurality of wavelengths; wherein performing OCT scanning comprises: providing the source light to a reference optical path and to a sample optical path, wherein providing the source light to a sample optical path comprises illuminating the target with the source light; and recording interference data corresponding to an interaction of a light from the reference optical path and a light from the sample optical path; processing the interference data; and identifying blood or one or more blood-features in the target based on an optical attenuation of light in or associated with the sample optical path by the blood or the one or more blood-features.

System, method, computer-accessible medium, and apparatus facilitating ultra-high resolution optical coherence tomography for automated detection of diseases

An exemplary system for generating an image(s) of a sample(s) can include, for example, an imaging arrangement that can include a superluminescent diode (SLD) configured to generate a radiation(s) to be provided to the sample(s), and a spectrometer configured to (i) sample an A-line sampling rate of at least about 200 kHz, (ii) receive a resultant radiation from the sample(s) based on the sampling rate, and (iii) generate information based on the resultant radiation, and a computer hardware arrangement configured to generate the image(s) of the sample(s) based on the information received from the spectrometer. The imaging arrangement can be an interferometric imaging arrangement, which can be an optical coherence tomography imaging (OCT) arrangement. The computer hardware arrangement can be further configured to facilitate a plurality of b-scan acquisitions of the sample(s) and facilitate the b-scan acquisitions in order to generate the image(s).

Lens fitting metrology with optical coherence tomography

Sensor data is captured with a sensor. The sensor data includes a lens-position of a prescription lens relative to a reference point of an optical coherence tomography (OCT) system. A mirror of a reference arm of the OCT system is positioned at an optical pathlength between an eye region of the prescription lens based at least in part on the sensor data. An OCT signal is generated while the mirror is positioned at the optical pathlength. At least one depth profile is generated that includes the prescription lens and the eye region.