# US 9,518,909 B2 · Particle detector and method for producing such a detector > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,518,909 B2 - Document ID: US9518909B2 - Status: Granted - Kind: B2 - Application number: 14/496,072 - Filed: 2014-09-25 - Published: 2015-04-30 - Granted: 2016-12-13 - Earliest claimed: 2010-07-22 - Assignees: Commissariat A L'energie Atomique Et Aux Energies Alternatives - Applicants: Commissariat A l'Energie Atomique Et Aux Energies Alternatives - Inventors: Sergio Nicoletti - Web page: https://patentgrep.com/patent/US9518909B2 ## CPC - G01N 15/0211: {Investigating a scatter or diffraction pattern} - G01N 15/06: Investigating concentration of particle suspensions (by weighing G01N5/00; investigating sedimentation of particle suspensions G01N15/04; investigating individual particles G01N15/10) - G01N 15/1484: {microstructural devices} - G01N 21/53: within a flowing fluid, e.g. smoke - G01N 21/532: {with measurement of scattering and transmission} - G01N 2015/0038: {Investigating nanoparticles} - G01N 2021/4726: {Detecting scatter at 90°} - G01N 2201/06113: Coherent sources; lasers - G01N 2201/0873: Using optically integrated constructions - 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) ## Abstract The invention relates to a particle detector including a substrate made of a semiconductor material, in which at least one through-cavity is formed, defined by an input section and an output section, wherein the input section thereof is to be connected to an airflow source, the substrate supporting: an optical means including at least one laser source, and at least one waveguide connected to the at least one laser source and leading into the vicinity of the output section of the cavity; and a photodetector located near the output section of the cavity and offset relative to the optical axis of the optical means. ## Claims ### Claim 1 A particle detector for detecting particles in the ambient air, the particle detector comprising: a substrate in which at least one through-cavity, delimited by an entry cross section and an exit cross section, is formed, the entry cross section being further configured to be connected to a source of an air flow, said air flow comprising the particles to be detected and capable of being received and directed by the said at least one through-cavity, said substrate supporting: an optical device comprising at least one laser source and at least one waveguide, which is connected to said at least one laser source and the end of which is located in proximity to the exit cross section of said cavity, and at least one photodetector located in proximity to the exit cross section of said cavity and offset with respect to the optical axis of said optical means, in order to detect the scattered light, wherein the optical device and the photodetector are located on the same face of the substrate, the optical device and the photodetector being produced simultaneously on the same substrate or being integral with the substrate. ### Claim 2 (depends on 1) The particle detector as claimed in claim 1, wherein said at least one cavity has a variable cross section which decreases from the entry cross section to the exit cross section. ### Claim 3 (depends on 1) The particle detector as claimed in claim 1, wherein the optical device includes at least one photonic device, at the opposite end of the waveguide from the laser source. ### Claim 4 (depends on 1) The particle detector as claimed in claim 1, wherein the particle detector comprises a plurality of photodetectors associated with the through-cavity. ### Claim 5 (depends on 1) The particle detector as claimed in claim 1, wherein the substrate comprises a plurality of through-cavities. ### Claim 6 (depends on 1) The particle detector as claimed in claim 1, wherein the substrate comprises a semiconductor material. ### Claim 7 (depends on 1) The particle detector as claimed in claim 1, wherein the photodetector is a photodiode. ### Claim 8 (depends on 1) The particle detector as claimed in claim 1, wherein the opposite end of the waveguide from the laser source is nanostructured so as to produce a focusing function. ### Claim 9 (depends on 1) The particle detector as claimed in claim 1, wherein the substrate comprises silicon. ### Claim 10 (depends on 1) The particle detector as claimed in claim 1, wherein the waveguide comprises: a first structure layer of a material having a first optical index n1, a second layer of a material having a second optical index n2 on this first layer, n2 being greater than n1, and a third structured layer of a material having a third optical index n3, wherein n3 is less than n2. ### Claim 11 (depends on 10) The particle detector as in claim 10, wherein the photodetector is offset with respect to the optical axis. ### Claim 12 (depends on 1) The particle detector as claimed in claim 1, wherein the through-cavity is formed on a surface of the substrate via etching. ### Claim 13 (depends on 1) The particle detector as claimed in claim 1, wherein the optical device and the photodetector are formed on a same face of the substrate. ### Claim 14 (depends on 1) The particle detector as claimed in claim 1, wherein the photodetector is selected from the group consisting of a pyrometer, bolometer, and photodiode. ### Claim 15 (depends on 1) The particle detector as claimed in claim 1, wherein the waveguide is configured to generate at least 7 light beams that are in the same plane and coincide with a plane of the substrate. ### Claim 16 (depends on 1) The particle detector as claimed in claim 1, wherein the laser source is configured to emit light in the infrared range, and wherein the photodetector includes an epitaxial germanium layer overlying a layer of silicon oxide. ### Claim 17 (depends on 1) The particle detector as claimed in claim 1, wherein the through-cavity has a funnel shape. ### Claim 18 (depends on 1) The particle detector as claimed in claim 1, wherein the particle detector comprises a plurality of photodetectors that are each associated with a plurality of said through cavities, and wherein said waveguide is configured to direct a light beam to each of said through cavities, said light beam being emitted from a single laser source. ### Claim 19 (depends on 18) The particle detector as claimed in claim 18, wherein each photodetector is offset with respect to the axis of the light beam emitted from the laser source, and are positioned facing the end of the waveguide and separated therefrom by each corresponding through cavity. ### Claim 20 (depends on 1) The particle detector as claimed in claim 1, wherein the particle detector is an optical particle counter.