# US 8,772,718 B2 · Electromagnetic radiation detecting device comprising an active bolometer and a shielded reference bolometer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,772,718 B2 - Document ID: US8772718B2 - Status: Granted - Kind: B2 - Application number: 13/270,633 - Filed: 2011-10-11 - Published: 2012-04-26 - Granted: 2014-07-08 - Earliest claimed: 2010-10-26 - Assignees: Commissariat A L'energie Atomique Et Aux Energies Alternatives - Applicants: Jean-Louis Ouvrier-Buffet; Jerome Meilhan - Inventors: Jean-Louis Ouvrier-Buffet; Jerome Meilhan - Web page: https://patentgrep.com/patent/US8772718B2 ## CPC - G01J 5/06: Arrangements for eliminating effects of disturbing radiation; Arrangements for compensating changes in sensitivity (for adjusting of solid angle of collected radiation G01J5/07; means for wavelength selection G01J5/0801) - G01J 5/02: Constructional details - G01J 5/04: Casings - G01J 5/045: {Sealings; Vacuum enclosures; Encapsulated packages; Wafer bonding structures; Getter arrangements (getter arrangements per se H10W76/48, H10P36/03)} - G01J 5/068: by controlling parameters other than temperature - G01J 5/20: using resistors, thermistors or semiconductors sensitive to radiation, e.g. photoconductive devices - G01J 5/70: Passive compensation of pyrometer measurements, e.g. using ambient temperature sensing or sensing of temperature within housing - G01J 5/12: using thermoelectric elements, e.g. thermocouples - G01J 2005/065: {by shielding} - 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 A device for detecting electromagnetic radiation that comprises an active bolometer provided with a first element sensitive to said electromagnetic radiation and a reference bolometer identical to the active bolometer, provided with a second element sensitive to said electromagnetic radiation. The active bolometer and reference bolometer are arranged close to one another on the same substrate. A cover covers at least the part of the second sensitive element exposed to the electromagnetic radiation and arranges an empty space between said second sensitive element and the cover. The inner wall of the cover is constituted by an absorbent layer made from a material absorbing at least the thermal radiations emitted by the second sensitive element. A reflecting shield forms at least a part of the outer wall exposed to said electromagnetic radiation. ## Claims ### Claim 1 A device for detecting electromagnetic radiation that comprises on a single substrate: an active bolometer equipped with a first element sensitive to said electromagnetic radiation, a reference bolometer identical to the active bolometer, equipped with a second element sensitive to said electromagnetic radiation, a cover having an outer wall and an inner surface facing towards the second sensitive element, said cover covering at least the part of the second sensitive element exposed to the electromagnetic radiation and arranging an empty space separating the second sensitive element and the inner surface and, a reflecting shield forming at least a part of the outer wall exposed to said electromagnetic radiation, wherein the entire inner surface of the cover is constituted by an absorbent layer, said layer being made from a material absorbing at least the thermal radiations emitted by the second sensitive element. ### Claim 2 (depends on 1) The device according to claim 1, wherein the cover completely encapsulates the second sensitive element. ### Claim 3 (depends on 1) The device according to claim 1, wherein the cover presses on the substrate. ### Claim 4 (depends on 3) The device according to claim 3, wherein the cover, with the substrate, forms a closed cavity in which the reference bolometer is housed. ### Claim 5 (depends on 1) The device according to claim 1, wherein the reference bolometer has an insulating microbridge structure comprising anchorage points and the cover presses on at least two of said anchorage points. ### Claim 6 (depends on 1) The device according to claim 1, wherein the absorbent layer is a multi-layer. ### Claim 7 (depends on 1) The device according to claim 1, wherein the absorbent layer is formed by at least one porous metallic absorbent material chosen from black gold, platinum, silver and chromium. ### Claim 8 (depends on 1) The device according to claim 1, wherein the absorbent layer is formed by at least one polymer material containing graphite. ### Claim 9 (depends on 1) The device according to claim 1, wherein the absorbent layer is formed by at least one resistive absorbent material chosen from titanium nitride and nichrome. ### Claim 10 (depends on 1) The device according to claim 1, wherein the cover comprises a support layer arranged between the absorbent layer and a reflecting shield and the active bolometer is encapsulated by a capsule, said support layer being constituted by a material transparent to the electromagnetic radiation emitted by the reference bolometer. ### Claim 11 (depends on 10) The device according to claim 10, wherein the transparent material of the support layer is chosen from single-crystal, polycrystalline or amorphous silicon, single-crystal or polycrystalline germanium and SiGe alloys. ### Claim 12 (depends on 1) The device according to claim 1, wherein the cover is 0.5 μm-5 μm above the reference bolometer. ### Claim 13 A device for detecting electromagnetic radiation that comprises on a single substrate: an active bolometer equipped with a first element sensitive to said electromagnetic radiation, a reference bolometer identical to the active bolometer, equipped with a second element sensitive to said electromagnetic radiation, a cover having an outer wall and an inner wall facing towards the second sensitive element, said cover covering at least the part of the second sensitive element exposed to the electromagnetic radiation and arranging an empty space separating the second sensitive element and the inner wall and, a reflecting shield forming at least a part of the outer wall exposed to said electromagnetic radiation, wherein the inner wall of the cover is constituted by an absorbent layer, said layer being made from a material absorbing at least the thermal radiations emitted by the second sensitive element, and wherein the reference bolometer has an insulating microbridge structure comprising anchorage points and the cover presses on at least two of said anchorage points.