# US 11,112,309 B2 · Digital micromirror device and kinematically tunable wavelength filter-based imaging systems > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,112,309 B2 - Document ID: US11112309B2 - Status: Granted - Kind: B2 - Application number: 16/754,040 - Filed: 2018-10-05 - Published: 2020-10-15 - Granted: 2021-09-07 - Earliest claimed: 2017-10-05 - Assignees: Case Western Reserve University - Applicants: Case Western Reserve University - Inventors: Ozan Akkus; Haithem A. B. Mustafa - Web page: https://patentgrep.com/patent/US11112309B2 ## CPC - G01J 3/44: Raman spectrometry; Scattering spectrometry {; Fluorescence spectrometry} - G01J 3/021: {using plane or convex mirrors, parallel phase plates, or particular reflectors} - G01J 3/0248: {using a sighting port, e.g. camera or human eye} - G01N 21/6456: {Spatial resolved fluorescence measurements; Imaging} - G01N 21/65: Raman scattering - G02B 26/0833: {the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD (G02B26/0825 takes precedence; micromechanical devices in general B81B)} - G01J 2003/1221: {Mounting; Adjustment} - 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) - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract An imaging system that includes a digital micromirror device (DMD) and a tunable filter, wherein the imagining system applicable for Raman imaging, can fluorescent imaging, phosphorescent imaging, photoluminescent imaging, all of which require excitation of a specimen at a particular wavelength and analyzing the reflected light from the specimen at a wavelength that is different from the excitation wavelength, so called inelastic light scattering—ILS. A reconfigurable DMD-based inverse, spatially offset Raman spectroscopy (SORS) system is also described. Beneficially, the DMD system in the excitation path provides a uniform intensity over the sample field of view. It is also configured to prevent sample damage. Placement of a second DMD in the return path of light enables selective rejection of light in space to obtain a reconfigurable inverse SORS system that enables collection of information from different layer depths of the sample using a single detector. ## Claims ### Claim 1 A Raman or inelastic light scattering imaging system, comprising: an excitation source providing a beam; a digital micromirror device arranged downstream from the excitation source in a beam path; the digital micromirror device comprising a plurality of mirrors; a spatial bandpass filter scheme with tunable wavelength and bandwidth that is positioned on a signal collection path by cross positioning of a broad high bandpass filter and a broad low bandpass filter set via a controllable rotatable stage and able to filter out a single wavenumber or multiple wavenumbers of interest to be collected by a collection device; wherein the spatial bandpass filter scheme is located downstream from a sample and upstream from a charged coupled device; and wherein a flip mirror is present downstream from the spatial bandpass filter scheme and can be switched to route the beam to either the charged-coupled device or a spectrometer located downstream from the flip mirror. ### Claim 2 (depends on 1) The imaging system according to claim 1, wherein the digital micromirror device converts the beam from the excitation source to a square or a circular shaped flat-top beam profile having a substantially uniform intensity of light that can be distributed on the sample. ### Claim 3 (depends on 1) The imaging system according to claim 1, wherein a beam expander is located in the beam path between the excitation source and the digital micromirror device, and wherein a dichroic mirror is located between the digital micromirror device and a sample in the beam path wherein light reflected from the sample is able to pass through the dichroic mirror. ### Claim 4 (depends on 3) The imaging system according to claim 3, wherein the spatial bandpass filter scheme is located downstream from the sample and dichroic mirror. ### Claim 5 (depends on 4) The imaging system according to claim 4, wherein the excitation source provides the single wavenumber. ### Claim 6 (depends on 3) The imaging system according to claim 3, wherein the beam expander increases a cross-sectional area of the beam to an area that is at least 25% larger than an area of the beam incident on the beam expander, and wherein the collection device is a 2D charge coupled device. ### Claim 7 (depends on 6) The imaging system according to claim 6, wherein the area of increase is at least 50%. ### Claim 8 (depends on 1) The imaging system according to claim 1, wherein a second spatial bandpass filter scheme with tunable wavelength and bandwidth is present and positioned in a signal collection path upstream from the digital micromirror device on an excitation path. ### Claim 9 An inverse spatially offset Raman spectroscopy system, comprising: an excitation source providing a beam; a digital micromirror device arranged downstream from the excitation source in a beam path; the digital micromirror device comprising a plurality of mirrors; an objective lens located downstream from the digital micromirror device that is adapted to impart an excitation area onto a sample; a second digital micromirror device or an area limiting filter located downstream in the beam path from the objective lens that only allows a Raman signal emerged from subsurface material, formed from a smaller cross-sectional area of the beam, to pass therethrough, wherein the smaller cross-sectional area of the beam is 50 percent or less of the cross-sectional excitation area transmitted to the second digital micromirror device or the area limiting filter; and a spectrometer located downstream from the second DMD or the area limiting filter that analyzes the collected Raman signal. ### Claim 10 (depends on 9) The inverse spatially offset Raman spectroscopy system according to claim 9, wherein the cross-sectional area is 5 to 50 percent. ### Claim 11 (depends on 10) The inverse spatially offset Raman spectroscopy system according to claim 10, wherein a focusing lens receives a small area of the beam from the second digital micromirror device or an area limiting filter which thereafter transmits the beam to the spectrometer. ### Claim 12 (depends on 9) The inverse spatially offset Raman spectroscopy system according to claim 9, wherein the second digital micromirror device is present and reflects an annular ring of light to a barrier such that the light does not reach the spectrometer. ### Claim 13 (depends on 9) The inverse spatially offset Raman spectroscopy system according to claim 9, wherein a collimation lens is located downstream from the excitation source and upstream from the first digital micromirror device, and wherein a bandpass filter is located between the first digital micromirror device and the dichroic mirror. ### Claim 14 An inverse spatially offset Raman spectroscopy system, comprising: an excitation source providing a beam; a digital micromirror device arranged downstream from the excitation source in a beam path; the digital micromirror device comprising a plurality of mirrors; an objective lens located downstream from the digital micromirror device that is adapted to impart an excitation area onto a sample; a second digital micromirror device located downstream in the beam path from the objective lens that only allows a Raman signal emerged from subsurface material, formed from a smaller cross-sectional area of the beam, to pass therethrough, wherein the second digital micromirror device reflects an annular ring of light to a barrier such that the light does not reach the spectrometer; and a spectrometer located downstream from the second DMD that analyzes the collected Raman signal. ### Claim 15 (depends on 14) The inverse spatially offset Raman spectroscopy system according to claim 14, wherein the smaller cross-sectional area of the beam is 50 percent or less of the cross-sectional excitation area transmitted to the second digital micromirror device or the area limiting filter. ### Claim 16 (depends on 15) The inverse spatially offset Raman spectroscopy system according to claim 15, wherein the cross-sectional area is 5 to 50 percent. ### Claim 17 (depends on 16) The inverse spatially offset Raman spectroscopy system according to claim 16, wherein a focusing lens receives a small area of the beam from the second digital micromirror device or an area limiting filter which thereafter transmits the beam to the spectrometer. ### Claim 18 (depends on 14) The inverse spatially offset Raman spectroscopy system according to claim 14, wherein a collimation lens is located downstream from the excitation source and upstream from the first digital micromirror device, and wherein a bandpass filter is located between the first digital micromirror device and the dichroic mirror.