US 12,326,365 B2
Two-dimensional terahertz radiation detector
Arthur Salmon, Palaiseau (FR); and Patrick Bouchon, Verrieres le Buisson (FR)
Assigned to OFFICE NATIONAL D'ETUDES ET DE RECHERCHES AÉROSPATIALES, Palaiseau (FR)
Appl. No. 17/920,492
Filed by OFFICE NATIONAL D'ETUDES ET DE RECHERCHES AÉROSPATIALES, Palaiseau (FR)
PCT Filed Apr. 16, 2021, PCT No. PCT/FR2021/050675
§ 371(c)(1), (2) Date Oct. 21, 2022,
PCT Pub. No. WO2021/214404, PCT Pub. Date Oct. 28, 2021.
Claims priority of application No. 2003967 (FR), filed on Apr. 21, 2020.
Prior Publication US 2023/0143274 A1, May 11, 2023
Int. Cl. H04N 23/12 (2023.01); G01J 3/02 (2006.01); G01J 3/10 (2006.01); H04N 23/23 (2023.01); G01J 3/28 (2006.01); G01J 5/00 (2022.01)
CPC G01J 3/108 (2013.01) [G01J 3/0208 (2013.01); H04N 23/12 (2023.01); H04N 23/23 (2023.01); G01J 2003/2813 (2013.01); G01J 2005/0077 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A two-dimensional terahertz radiation detector, comprising:
a spectral conversion element for electromagnetic radiation, comprising a two-dimensional support, antennas referred to as terahertz antennas, which are carried by the two-dimensional support and adapted for having an absorption peak for the electromagnetic radiation when a wavelength of said electromagnetic radiation is between 30 μm and 3 mm, corresponding to what is referred to as terahertz radiation, and further comprising infrared emitters which are also carried by the two-dimensional support, those of said infrared emitters which are aligned with one of the terahertz antennas, parallel to a direction perpendicular to the two-dimensional support, being thermally coupled with said terahertz antenna so that absorption of terahertz radiation by each terahertz a causes, by each infrared emitter coupled with said terahertz antenna, an emission of infrared electromagnetic radiation having a wavelength which is comprised between 1 μm and 30 μm, referred to as infrared radiation;
an image sensor, of the matrix type and having a surface, referred to as a photosensitive surface, which is sensitive to the infrared radiation; and
an imaging system, efficient for the infrared radiation and adapted for optical conjugation of the infrared emitters with the photosensitive surface of the image sensor,
wherein the imaging system comprises an array of converging microlenses which are placed next to each other parallel to the two-dimensional support of the spectral conversion element and to the photosensitive surface of the image sensor, said array of microlenses being located between the spectral conversion element and the image sensor, facing the infrared emitters, and being such that only one of the microlenses is dedicated to each terahertz antenna, separately from the other terahertz antennas, so as to form, in an area of the photosensitive surface of the image sensor, an image of each infrared emitter that is coupled to said terahertz antenna, or else such that a single one of the microlenses is dedicated to a group of adjacent terahertz antennas, separately from other groups of adjacent terahertz antennas, so as to form, in an area of the photosensitive surface of the image sensor, an image of each infrared emitter that is coupled to said group of adjacent terahertz antennas,
the areas in the photosensitive surface of the image sensor which correspond to separate terahertz antennas, or to separate groups of adjacent terahertz antennas, being disjoint,
and wherein some of the infrared emitters of the spectral conversion element, forming a subset, are not aligned with any of the terahertz antennas along the direction perpendicular to the two-dimensional support, and each infrared emitter of said subset is imaged by one of the microlenses on the photosensitive surface of the image sensor, so that said image sensor captures, at a location in said photosensitive surface which corresponds to the image of an infrared emitter of said subset, a signal representative of an average temperature of the spectral conversion element.