Office National D'etudes Et De Recherches Aerospatiales

Centre National De La Recherche Scientifique

Office National D'etudes Et De Recherches Aerospatiales (onera)

Commissariat &#xc0; L'&#xc9;nergie Atomique Et Aux &#xc9;nergies Alternatives

Office Nathional D'etudes Et De Recherches Aerospatiales—onera—chemie De La Huniere

Centre National De La Recherche Scientifique-cnrs

Patrick Bouchon

Riad Haidar

Jean-Luc Pelouard

Fabrice Pardo

Riad Haïdar

Julien Jaeck

Mathilde Makhsiyan

Jean-Jacques Yon

Grégory Vincent

Jérôme Primot

Joël Deschamps

Michaël Verdun

Stéphane Collin

Cindy Bellanger

Emilie Steveler

Alain Kattnig

Paul Chevalier

Emilie Sakat

Micke Boher

Quentin Levesque

Sabine Suffis

Charlie Koechlin

Baptiste Fix

Sophie Thetas

Arthur Salmon

Haidar Riad

A two-dimensional terahertz radiation detector includes a spectral conversion element, an array of microlenses, and a matrix image sensor. Such a detector can be particularly compact, light, and inexpensive. For some embodiments, it can be used to produce multispectral images of an external scene, from terahertz radiation that originates from the scene.

Two-dimensional terahertz radiation detector

Disclosed is a spectral filter including a plurality of Fabry-Perot structures which are collectively carried by a support, and coupled together so as to produce a coupling resonance that is distinct from individual resonances of each of the Fabry-Perot structures. The coupling resonance may have a higher quality factor than the quality factors of the individual resonances. Each Fabry-Perot structure includes two portions of metal surfaces which are parallel to a face of the substrate, so that electromagnetic radiation wave components propagating within each Fabry-Perot structure, and which contribute to the coupling resonance, have a direction of propagation that is parallel to the face of the substrate.

Spectral filter comprising at least two coupled Fabry-Perot structures

A device for imaging and delivering spectroscopic information comprises an objective (), an image sensor () and an optical component () having a spectral differentiation function. The optical component having a spectral differentiation function modifies the image of a point in different ways for at least two colours, so that a form of the image of the point delivers spectroscopic information that appears directly in the image as captured by the image sensor. Such device may be used in a detection and/or surveillance system, which then possesses a lower probability of false alarm value.

Device for imaging and delivering spectroscopic information

According to a first aspect, the present description relates to a device for optically encoding an image, which device is intended to be observed in at least one first spectral band of observation. The encoding device comprises a supporting structure and a set of metal-dielectric-metal plasmonic antennae formed on said supporting structure, each plasmonic antenna being resonant at at least one wavelength comprised in said first spectral band of observation, the plasmonic antennae being arranged spatially on the supporting structure in such a way as to form at least one first spatial encoding of said image in said first spectral band of observation.

Device and method for optically encoding an image

A photodetector includes a Helmholtz resonator and a photosensitive structure that is placed in an electric-field-concentrating interval forming part of the Helmholtz resonator. Such a photodetector is in particular suitable for imaging applications. The wavelength of the radiation to be detected is determined by dimensions of the Helmholtz resonator, within a detection spectral interval of the photosensitive structure.

Photodetector with helmholtz resonator

A spectral conversion element for electromagnetic radiation includes Terahertz antennas and infrared antennas which are distributed in pixel zones. The Terahertz antennas and the infrared antennas which are in one same pixel zone are thermally coupled, and those which are in different pixel zones are uncoupled. Such an element enables the capture of images which are formed with Terahertz radiation, by using an infrared image detector.

Spectral conversion element for electromagnetic radiation

According to one aspect, the invention relates to an angular optical filtering element (E) optimized for angular filtering about a given operating angle of incidence (&#x3b8;) in a given spectral band. The angular filtering element (E) comprises a first nanostructured, band-pass, spectral filter (11, 301) and a second nanostructured, band-pass, spectral filter (12, 302). Each of the first and second spectral filters comprises, respectively, in said spectral band, a first and a second central filtering wavelength that respectively has a first and second angular dispersion curve defined depending on the angle of incidence (&#x3b8;) on the optical filtering element (E), the curves of angular dispersion being secant about the operating angle of incidence (&#x3b8;) of the optical filtering element. The invention applies to the production of a selective angular filtering device and to a multidirectional optical detection system.

Angular optical filtering element for angular filtering having controlled angular selectivity

According to one aspect, the invention relates to a device () for controlling the phase of an incident optical wavefront of wavelength comprised in a spectral band of given use, comprising a substrate () that is at least partially transparent in said spectral band and a set of strips () arranged substantially perpendicularly to the surface of the substrate, characterized in that: said set of strips comprises an alternation of juxtaposed strips respectively made of a metal (), of a first dielectric () and of at least one second dielectric () different from the first dielectric, such as to form juxtaposed metal/multi dielectric/metal (MmultiDM) structures (S) of subwavelength widths (w), each structure forming a cavity having one or more propagation modes&#x2014;the respective thicknesses of the strips made of the first dielectric and of the second dielectric(s) are adjusted in each of said MmultiDM structures to induce a local shift (&#x394;&#x3a6;) in the phase of the wavefront, the local phase shift being dependent on the effective index of the mode(s) able to propagate in said cavity.

Device for controlling the phase of an optical wavefront having juxtaposed metal-multidielectric-metal structures to induce a local shift

According to one aspect, the invention relates to a microbolometer array for thermal detection of light radiation in a given spectral band, comprising a supporting substrate and an array of microbolometers () of given dimensions, arranged in an array. Each of said microbolometers comprises a membrane () suspended above said supporting substrate, said membrane consisting of an element () for absorbing the incident radiation and a thermometric element () in thermal contact with the absorber, electrically insulated from said absorber element. The absorber element comprises at least one first metal/insulator/metal (MIM) structure comprising a multilayer of three superposed films of submicron-order thickness i.e. a first metallic film (), a dielectric film (), and a second metallic film (), said MIM structure being able to have a resonant absorption of said incident radiation at at least one wavelength in said spectral band. The area of the microbolometer pixel covered by said membrane () is less than or equal to half of the total area of the microbolometer pixel.

Microbolometer array with improved performance

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Verrieres le Buisson, France

Patrick Bouchon