# US 2017/0234797 A1 · Method and apparatus for measuring inelastic scattering > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2017/0234797 A1 - Document ID: US20170234797A1 - Status: Published application - Kind: A1 - Application number: 15/410,867 - Filed: 2017-01-20 - Published: 2017-08-17 - Earliest claimed: 2016-01-21 - Assignees: TimeGate Instruments Oy - Applicants: TimeGate Instruments Oy - Inventors: Juha KOSTAMOVAARA; Ilkka NISSINEN; Jan NISSINEN; Rami AIKIO; Jussi TENHUNEN; Lauri KURKI - Web page: https://patentgrep.com/patent/US20170234797A1 ## CPC - G01N 21/65: Raman scattering - G01J 3/44: Raman spectrometry; Scattering spectrometry {; Fluorescence spectrometry} - G01J 2001/442: {Single-photon detection or photon counting} - 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) - 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 An apparatus, includes an illuminating light source and illuminating optics arranged to illuminate a sample region with illuminating light pulses, light gathering optics to gather Raman scattered light pulses from the sample region, a spectral disperser and a detector array for measuring the spectral intensity distribution of Raman scattered light pulses obtained from the sample region and an auxiliary detector for providing an indicator signal indicative of elastic scattering coefficient of the sample region. The apparatus is arranged to form a first output spectrum from the spectral intensity distribution of a first group of Raman scattered light pulses. The pulses of the first group of Raman scattered light pulses are obtained from the sample region when the indicator signal indicates that an object is located in the sample region. ## Claims ### Claim 1 A method for measuring Raman scattering, the method comprising: varying composition in a sample region, providing an indicator signal indicative of elastic scattering coefficient of the sample region, illuminating the sample region with illuminating light pulses, and forming a first output spectrum from the spectral intensity distribution of a first group of Raman scattered light pulses, wherein the pulses of said first group of Raman scattered light pulses are obtained from the sample region when the indicator signal indicates that an object is located in the sample region. ### Claim 2 (depends on 1) The method of claim 1, comprising: generating triggered illuminating light pulses by triggering an illuminating light source based on the indicator signal, and forming the first output spectrum from the spectral intensity distribution of Raman scattered light pulses obtained when the sample region is illuminated by said triggered illuminating light pulses. ### Claim 3 (depends on 2) The method of claim 2, comprising changing the state of a trigger signal for triggering the illuminating light source when the indicator signal exceeds a predetermined level. ### Claim 4 (depends on 1) The method of claim 1, comprising determining whether a Raman scattered light pulse belongs to a first category or not, wherein the Raman scattered light pulse is determined to belong to the first category only if the indicator signal exceeds a predetermined level when the Raman scattered light pulse is obtained from the sample region, and forming the first output spectrum from the spectral intensity distribution of Raman scattered light pulses of the first category. ### Claim 5 (depends on 1) The method of claim 1, comprising determining whether a Raman scattered light pulse belongs to a first category or to a second category based on the indicator signal, wherein the Raman scattered light pulse is determined to belong to the first category if the indicator signal exceeds a predetermined level when the Raman scattered light pulse is obtained from the sample region, and wherein the Raman scattered light pulse is determined to belong to the second category if the indicator signal is lower than said predetermined level when the Raman scattered light pulse is obtained from the sample region, forming the first output spectrum from the spectral intensity distribution of Raman scattered light pulses of the first category, and forming a second output spectrum from the spectral intensity distribution of Raman scattered light pulses of the second category. ### Claim 6 (depends on 1) The method of claim 1, wherein the spectral intensity distribution of the Raman scattered light pulses is measured by a detector, and the method comprises controlling operation of the detector based on the indicator signal. ### Claim 7 (depends on 1) The method of claim 1, wherein the spectral intensity distribution of the Raman scattered light pulses is measured by a detector, and the method comprises enabling operation of the detector based on the indicator signal. ### Claim 8 (depends on 1) The method of claim 1, wherein the spectral intensity distribution of the Raman scattered light pulses is measured by using an array of single photon avalanche photodiodes and a set of counters arranged to count pulses provide by the photodiodes, wherein operation of said set of counters is enabled based on the indicator signal. ### Claim 9 (depends on 1) The method of claim 1, wherein the composition is varied by moving a heterogeneous substance with respect to the sample region, and the heterogeneous substance comprises a plurality of objects suspended in a carrier medium. ### Claim 10 (depends on 1) The method of claim 1 comprising estimating a volume fraction of objects based on the indicator signal. ### Claim 11 (depends on 1) The method of claim 1, wherein the illuminating light pulses are focused to the sample region through a first lens, and the Raman scattered light from the sample region is gathered through said first lens. ### Claim 12 An apparatus, comprising: an illuminating light source and illuminating optics arranged to illuminate a sample region with illuminating light pulses, light gathering optics to gather Raman scattered light pulses from the sample region, a spectral disperser and a detector array for measuring the spectral intensity distribution of Raman scattered light pulses obtained from the sample region, an auxiliary detector for providing an indicator signal indicative of elastic scattering coefficient of the sample region, wherein said apparatus is arranged to form a first output spectrum from the spectral intensity distribution of a first group of Raman scattered light pulses, wherein the pulses of said first group of Raman scattered light pulses are obtained from the sample region when the indicator signal indicates that an object is located in the sample region. ### Claim 13 (depends on 12) The apparatus of claim 12, wherein the apparatus is arranged to trigger the illuminating light pulses according to the indicator signal, and wherein the apparatus is arranged to form the first output spectrum from the spectral intensity distribution of Raman scattered light pulses obtained when the sample region is illuminated by said triggered illuminating light pulses. ### Claim 14 (depends on 12) The apparatus of claim 12, wherein the apparatus is arranged to determine whether a Raman scattered light pulse belongs to a first category or not, wherein the Raman scattered light pulse is determined to belong to the first category only if the indicator signal exceeds a predetermined level when the Raman scattered light pulse is obtained from the sample region, and wherein the apparatus is arranged to form the first output spectrum from the spectral intensity distribution of Raman scattered light pulses of the first category.