# US 11,441,889 B2 · Apparatus, systems, and methods for detecting light > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,441,889 B2 - Document ID: US11441889B2 - Status: Granted - Kind: B2 - Application number: 16/757,720 - Filed: 2018-10-19 - Published: 2021-12-02 - Granted: 2022-09-13 - Earliest claimed: 2017-10-27 - Assignees: Nokia Technologies Oy - Applicants: Nokia Technologies Oy - Inventors: Xin Yuan - Web page: https://patentgrep.com/patent/US11441889B2 ## CPC - G01B 9/02091: Tomographic interferometers, e.g. based on optical coherence - A61B 5/0066: {Optical coherence imaging} - A61B 5/0073: {by tomography, i.e. reconstruction of 3D images from 2D projections (A61B5/0066 takes precedence)} - G01B 9/02002: using two or more frequencies - G01B 9/02041: {characterised by particular imaging or detection techniques} - G01B 9/02044: {Imaging in the frequency domain, e.g. by using a spectrometer} - G01B 9/02087: {Combining two or more images of the same region} - G01J 3/0229: {using masks, aperture plates, spatial light modulators or spatial filters, e.g. reflective filters} - G01J 3/2803: {using photoelectric array detector} - G01J 3/2823: {Imaging spectrometer} - G01J 3/2846: {using modulation grid; Grid spectrometers} - A61B 3/1225: {using coherent radiation} - G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - G01J: MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY (light sources F21, H01J, H01K, H05B; investigating properties of materials by optical means G01N) ## Abstract 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. ## Claims ### Claim 1 A method for obtaining a three dimensional image corresponding to at least a three-dimensional part of an object, the method comprising: spatially modulating, using at least a modulator, an input beam of light, wherein the input beam of light is a spectral domain signal obtained from an optical coherence tomography arrangement and comprises light reflected from the object that comprises different frequencies of light providing information about different depths within the object, and wherein the modulator comprises at least a first plurality of first portions having a first transparency to the input beam of light and at least a second plurality of second portions having a different transparency to the input beam of light, the first and second portions of the modulator being arranged in a pixelated arrangement; dispersing the modulated beam of light; detecting the dispersed beam of light as a single measurement; converting the detected beam of light into electrical output signals; and providing the three dimensional image of at least the three-dimensional part of the object from the electrical output signals. ### Claim 2 (depends on 1) The method of claim 1, wherein the modulator comprises a coded aperture. ### Claim 3 (depends on 2) The method of claim 2, further comprising: using the coded aperture to modulate the beam of light and moving the coded aperture so that different spectral bandwidths are detected sequentially. ### Claim 4 (depends on 2) The method of claim 2, wherein the coded aperture is a two dimensional coded aperture. ### Claim 5 (depends on 1) The method of claim 1, wherein the transparency of the first and second portions of the modulator are wavelength dependent. ### Claim 6 (depends on 1) The method of claim 1, wherein the first and second portions of the modulator are arranged in a random or pseudo random pattern. ### Claim 7 (depends on 1) The method of claim 1, wherein the modulator is arranged to convert a three dimensional signal into a two dimensional signal. ### Claim 8 (depends on 1) The method of claim 1, wherein providing the three dimensional image of at least the three-dimensional part of the object from the electrical output signals uses a compressive sensing inversion algorithm that converts candidate three dimensional images into the spectral domain using a Fourier transform. ### Claim 9 An apparatus for obtaining a three dimensional image corresponding to at least a three-dimensional part of an object, the apparatus comprising: a modulator configured to spatially modulate an input beam of light, wherein the input beam of light is a spectral domain signal obtained from an optical coherence tomography arrangement and comprises light reflected from an object that comprises different frequencies of light providing information about different depths within the object, and wherein the modulator comprises at least a first plurality of first portions having a first transparency to the input beam of light and at least a second plurality of second portions having a different transparency to the input beam of light, the first and second portions of the modulator are arranged in a pixelated arrangement; a dispersing element configured to disperse the modulated beam of light; and a detector configured to detect the dispersed beam of light as a single measurement and convert the detected beam of light into electrical output signals, wherein the apparatus is configured to provide a three dimensional image of at least the three-dimensional part of the object based at least upon the electrical output signals. ### Claim 10 (depends on 9) The apparatus of claim 9, wherein the modulator comprises a coded aperture, the modulator being configured to modulate the beam of light and move the coded aperture so that different spectral bandwidths are detected sequentially. ### Claim 11 (depends on 10) The apparatus of claim 10, wherein the coded aperture is a two dimensional coded aperture. ### Claim 12 (depends on 9) The apparatus of claim 9, wherein the modulator is arranged to be moveable relative to the dispersing element and the detector. ### Claim 13 (depends on 9) The apparatus of claim 9, wherein the dispersing element comprises a prism. ### Claim 14 (depends on 9) The apparatus of claim 9, wherein the detector comprises at least one of a: charge coupled device or a complementary metal-oxide semiconductor sensor. ### Claim 15 (depends on 9) The apparatus of claim 9, wherein the detector comprises a two dimensional array of sensors. ### Claim 16 (depends on 9) The apparatus of claim 9, wherein the first and second portions of the modulator correspond to pixels in the detector. ### Claim 17 (depends on 9) The apparatus of claim 9, wherein the transparency of the first and second portions of the modulator are wavelength dependent. ### Claim 18 (depends on 9) The apparatus of claim 9, wherein the first and second portions of the modulator are arranged in a random or pseudo random pattern. ### Claim 19 (depends on 9) The apparatus of claim 9, wherein the modulator is configured to convert a three dimensional signal into a two dimensional signal. ### Claim 20 (depends on 9) The apparatus of claim 9, wherein the apparatus is configured to provide the three dimensional image of at least the three-dimensional part of the object from the electrical output signals using a compressive sensing inversion algorithm that converts candidate three dimensional images into the spectral domain using a Fourier transform. ### Claim 21 A sensing system comprising: a plurality of apparatuses, where respective apparatuses of the plurality of apparatuses comprise a modulator configured to spatially modulate an input beam of light, wherein the input beam of light is a spectral domain signal obtained from an optical coherence tomography arrangement and comprises light reflected from an object that comprises different frequencies of light providing information about different depths within the object, wherein the modulator comprises at least a first plurality of first portions having a first transparency to the input beam of light and at least a second plurality of second portions having a different transparency to the input beam of light, wherein the first and second portions of the modulator are arranged in a pixelated arrangement, respective apparatuses of the plurality of apparatuses further comprising a dispersing element configured to disperse the modulated beam of light and a detector configured to detect the dispersed beam of light as a single measurement and convert the detected beam of light into electrical output signals; and one or more filters arranged to divide the input beam of light into a plurality of different spectral bandwidths, wherein the sensing system is arranged so that input beams of light of different bandwidths are provided to different apparatuses of the plurality of apparatuses. ### Claim 22 (depends on 21) The sensing system of claim 21, wherein respective apparatuses of the plurality of apparatuses are configured to provide the three dimensional image of at least the three-dimensional part of the object from the electrical output signals using a compressive sensing inversion algorithm that converts candidate three dimensional images into the spectral domain using a Fourier transform.