# US 2014/0192161 A1 · Three-dimensional reconstruction of a millimeter-wave scene by optical up-conversion and cross-correlation detection > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0192161 A1 - Document ID: US20140192161A1 - Status: Published application - Kind: A1 - Application number: 14/150,213 - Filed: 2014-01-08 - Published: 2014-07-10 - Earliest claimed: 2013-01-10 - Assignees: Phase Sensitive Innovations, Inc. - Applicants: Phase Sensitive Innovations, Inc. - Inventors: Janusz Murakowski; Garrett Schneider; Shouyuan Shi; Christopher A. Schuetz; Dennis W. Prather - Web page: https://patentgrep.com/patent/US20140192161A1 ## CPC - G01B 15/04: for measuring contours or curvatures - G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS ## Abstract An apparatus and method may be used to create images, e.g., three-dimensional images, based on received radio-frequency (RP), e.g., millimeter wave, signals carrying image data. The RF signals may be modulated onto optical carrier signals, and the resulting modulated optical signals may be cross-correlated. The resulting cross-correlations may be used to extract image data that may be used to generate three-dimensional images. ## Claims ### Claim 1 A method of imaging, including: modulating a plurality of radio-frequency (RF) signals bearing image information onto a corresponding plurality of optical signals to obtain a corresponding plurality of modulated optical signals; obtaining cross-correlations of the plurality of modulated optical signals; and processing the cross-correlations to generate an image. ### Claim 2 (depends on 1) The method of claim 1, wherein the obtaining cross-correlations includes: passing respective pairs of the plurality of modulated optical signals through one or more 50/50 beam splitters to generate splitter output signals; and measuring the intensities of the splitter output signals corresponding to a respective pair of the plurality of modulated optical signals to obtain cross-correlation information about the respective pair of the plurality of modulated optical signals. ### Claim 3 (depends on 1) The method of claim 1, wherein the plurality of modulated optical signals are carried on respective optical fibers, and wherein obtaining cross-correlations includes: splitting each of the respective modulated optical signals of the plurality of modulated optical signals carried on a respective optical fiber into two respective split optical signals conveyed onto two respective further optical fibers, wherein the two respective further optical fibers corresponding to a particular one of the plurality of modulated optical signals are physically oriented into a vertical further optical fiber and a horizontal optical fiber; organizing the resulting plurality of vertical further optical fibers and horizontal further optical fibers into respective vertical and horizontal fiber arrays; splitting optical output beams of the respective further optical fibers corresponding to the plurality of modulated optical signals into respective numbers of free-propagating beams, wherein respective numbers of free-propagating beams for each of the respective optical output beams are equal to a number of the plurality of modulated optical signals; and combining the free-propagating beams corresponding to the vertical fiber array with the free-propagating beams corresponding to the horizontal fiber array to obtain one or more arrays of combined beams. ### Claim 4 (depends on 3) The method of claim 3, wherein the combining the free-propagating beams is performed using a splitter/combiner. ### Claim 5 (depends on 3) The method of claim 3, further comprising detecting the combined beams. ### Claim 6 (depends on 1) The method of claim 1, wherein processing the cross-correlations to generate an image operates to produce a three-dimensional image. ### Claim 7 An optical imaging apparatus, including: a plurality of optical modulators configured to receive respective image-information-bearing radio-frequency (RF) signals of a plurality of RF signals and to modulate the respective RF signals onto respective optical signals of a plurality of optical signals to obtain a plurality of modulated optical signals; a correlation engine configured to obtain and detect cross-correlations of the plurality of modulated optical signals; and a processing device configured to generate an image based upon the detected cross-correlations. ### Claim 8 (depends on 7) The apparatus of claim 7, wherein the correlation engine comprises one or more 50/50 beam splitters, and wherein the detector is configured to detect one or more outputs of the one more more 50/50 beam splitters. ### Claim 9 (depends on 7) The apparatus of claim 7, further comprising a plurality of optical fibers coupled to carry respective ones of the plurality of modulated optical signals to the correlation engine. ### Claim 10 (depends on 9) The apparatus of claim 9, wherein the correlation engine comprises: vertical and horizontal optical fiber arrays formed by splitting each of the respective modulated optical signals of the plurality of modulated optical signals carried on a respective optical fiber into two respective split optical signals conveyed onto two respective further optical fibers, wherein two respective further optical fibers corresponding to a particular one of the plurality of modulated optical signals are physically oriented into a vertical further optical fiber and a horizontal optical fiber that form the vertical and horizontal fiber arrays; and wherein the correlation engine is configured to split optical output beams of the respective further optical fibers of the vertical and horizontal optical fiber arrays into respective numbers of free-propagating beams, wherein respective numbers of free-propagating beams for each of the respective optical output beams are equal to a number of the plurality of modulated optical signals. ### Claim 11 (depends on 10) The apparatus of claim 10, wherein the correlation engine further comprises: a beam splitter/combiner configured to combine the free-propagating beams corresponding to the vertical fiber array with the free-propagating beams corresponding to the horizontal fiber array to obtain one or more arrays of combined beams. ### Claim 12 (depends on 7) The apparatus of claim 7, wherein the processing device is configured to generate a three-dimensional image based on the detected cross-correlations. ### Claim 13 An imaging apparatus, including: means for modulating a plurality of radio-frequency (RF) signals bearing image information onto a corresponding plurality of optical signals to obtain a corresponding plurality of modulated optical signals; means for obtaining cross-correlations of the plurality of modulated optical signals; and means for processing the cross-correlations to generate an image.