Abstract: A device for the photoacoustic characterisation of a gaseous substance, includes a chamber intended to contain the gaseous substance to characterise and into which a light beam is injected. The chamber is delimited, inter alia, by an inner face, on which a part of the light beam is reflected. This inner face is etched so as to have recesses, each recess being delimited laterally by a lateral surface of which a part at least is tilted, with respect to an average plane of the inner face, by a given tilt angle (?).

Abstract: The invention relates to a diffuser 3 intended to be facing a light source 1 comprising a transmission layer 10 and a diffusion layer 22, 23 intended to diffuse a light transmitted by the light source, the diffuser being characterised in that the diffusion layer comprises a plurality of metal structures 200, 200a, 200b, called metal nanostructures, having dimensions less than a wavelength of the light transmitted, said metal nanostructures having varied sizes and being distributed within the diffusion layer such that adjacent metal nanostructures have between them, varied distances and preferably less than the wavelength of the light transmitted. The invention also relates to a method for manufacturing such a diffuser, and a display system comprising such a diffuser.

Abstract: An optical device for a biological or chemical sensor includes: an absorption cavity configured to receive a biological or chemical medium; an injection waveguide to inject an analysis light beam into the absorption cavity; and an extraction waveguide to extract a measurement light beam, corresponding to the analysis light beam after transit through the absorption cavity. The absorption cavity has a shape of a right cylinder with an elliptical base. One end of the injection waveguide is placed at a first focus of the ellipse and one and of the extraction waveguide is placed at a second focus of the ellipse. A core of the injection waveguide and a core of the extraction waveguide each have a tip-shaped end, with a constant height in a plane parallel to the generatrix of the right cylinder and a tip-shaped cross section in planes parallel to the base of the right cylinder.

Abstract: The invention relates to a diffuser 3 intended to receive the light transmitted by a visible light source 1 comprising a transmission layer 10 and a diffusion layer 22 intended to diffuse said light, the diffuser being characterised in that the diffusion layer comprises a plurality of metal nanostructures 200, each of these metal nanostructures having, in projection in a main extension plane xy, a longitudinal dimension L along a longitudinal axis and a transverse dimension l along a transverse axis, said longitudinal and transverse dimensions being different to one another and the transverse dimension l being less than 650 nm, and in that these metal nanostructures are further distributed within the diffusion layer such that at least two adjacent metal nanostructures are respectively oriented along two non-parallel longitudinal axes. The invention also relates to a method for manufacturing such a diffuser, and a display system comprising such a diffuser.

Abstract: A photodiode which includes a core of a first waveguide that terminates in a tapered termination that extends above a core, made of germanium or of SiGe, of a second waveguide, a matching strip that extends opposite the tapered termination on one side and opposite the core of the second waveguide on the opposite side, this matching strip being coupled optically to the core of the second waveguide by an evanescent coupling and including a first zone inside which its effective propagation index is equal to the effective propagation index of a second zone of the tapered termination, these first and second zones optically coupling the tapered termination to the matching strip through a modal coupling, and a low-index layer that extends between the matching strip and the tapered termination.

Abstract: The invention relates to an infrared device comprising a resistive element suspended in a cavity formed in a main element, and capable of transmitting infrared radiation when it is fed with an electric current. In particular, the main element is at least partly covered on the outer surface thereof and/or the inner surface thereof with a reflective coating. The use of the reflective coating makes it possible to at least partly contain infrared radiation transmitted by the resistive element in the cavity.

Abstract: An optical cavity includes: a first elliptical mirror, having a first focal axis A1, and designed to reflect a light beam emitted by a light source; a second elliptical mirror, having a second focal axis A2; a third elliptical mirror, having a third focal axis A3, the light beam exiting from the third elliptical mirror being designed to be received by a detector; a first reflector, arranged to reflect the light beam exiting from first elliptical mirror in the direction of the second elliptical mirror, and arranged to reflect the light beam exiting from second elliptical mirror in the direction of the third elliptical mirror; the first, second and third elliptical mirrors being arranged so that A1, A2 and A3 have a point of intersection F, corresponding to a focus common to the first, second and third elliptical mirrors.

Abstract: A method for observing a fluorescent sample, the sample comprising a fluorescent agent that emits fluorescence light, in a fluorescence spectral band, when it is illuminated by excitation light, in an excitation spectral band, the method comprising the following steps: a) placing the sample on a holder; b) illuminating the sample, with an excitation light source, in the excitation spectral band, the light emitted by the light source propagating along a propagation axis; c) detecting fluorescence light, in the fluorescence spectral band, with an image sensor; the method being such that the holder comprises a thin layer formed from a first material, of a first refractive index, the thin layer lying in a holder plane perpendicular to the propagation axis, the thin layer comprising a first photonic crystal and second photonic crystals configured to confine the excitation light and the fluorescence light in the thin layer.

Abstract: A particle detector is provided, including at least one channel configured to receive at least one fluid including particles; one optical inlet configured to receive at least one incident luminous radiation; one first plurality of reflecting surfaces arranged between the optical inlet and the channel; one matrix of photo detectors arranged facing the channel; and one second plurality of reflecting surfaces arranged between the channel and the matrix of photo detectors such that the channel is disposed between the first and the second pluralities of reflecting surfaces.

Abstract: A device for detecting electromagnetic radiation includes at least one thermal detector, placed on a substrate; an encapsulating structure forming a cavity housing the thermal detector, including at least one thin encapsulating layer; and at least one Fabry-Perot interference filter, formed by first and second semi-reflective mirrors that are separated from each other by a structured layer. A high-index layer of one of the semi-reflective mirrors is at least partially formed from the thin encapsulating layer.

Abstract: An optical device including: a waveguide, including a core having a refractive index, for guiding a quasi monochromatic light radiation, of a central wavelength, in a first direction and transmitting the radiation through an exit facet of the waveguide to the external environment according to a transmission coefficient, the exit facet being substantially perpendicular to the first direction, a filter blade, for example an air blade, disposed in the waveguide, parallel to the exit facet and at a first non-zero distance from the exit facet, the filter blade having, in the first direction, a first thickness, the first distance and the first thickness configured so that the transmission coefficient of the waveguide is equal to a first transmission coefficient at the central wavelength.

Abstract: The invention relates to an infrared device comprising a resistive element suspended in a cavity formed in a main element, and capable of transmitting infrared radiation when it is fed with an electric current. In particular, the main element is at least partly covered on the outer surface thereof and/or the inner surface thereof with a reflective coating. The use of the reflective coating makes it possible to at least partly contain infrared radiation transmitted by the resistive element in the cavity.

Abstract: A device for coupling a first waveguide with a second waveguide, wherein the core of the second guide includes an end portion having at least a flat end wall rotated facing, and preferably, in contact with the core of the first guide, a flared part of convex shape extending the end wall by extending from the first guide, the flared part having a section which increases by extending from the first guide, a narrowing, a main portion, extending the end portion by extending from the first guide and having a substantially constant section.

Abstract: The present disclosure relates to shaping of optic beams at the inputs/outputs of a photonic chip, the spectral widening of the light coupled to this chip, and a method for manufacturing the chip. The photonic chip includes a light guiding layer supported by a substrate. The chip includes at least one light guiding structure made of silicon coupled on one side to a vertical coupler and on another side to an optical component integrated in the light guiding layer. The photonic chip has a front face on the vertical coupler side and a rear face on the substrate side. A collimation structure of digital lens type is integrated at the level of the rear face to collimate the mode size of the light beam incident on the lens and coming from the vertical coupler.

Abstract: The invention aims for an avalanche photodiode comprising an absorption zone (2), a multiplication zone (3), a first electrode and a second electrode. The photodiode further comprises a waveguide (10) forming a curved closed circuit capable of guiding a luminous flux over several turns of said circuit. The absorption zone extends over a portion at least of said waveguide, and the multiplication zone, the first and second electrodes extend along one part at least of the curved closed circuit. The waveguide is preferably an edge waveguide forming a ring and comprising an absorption zone made of germanium of width less than 200 nm. The photodiode according to the invention has an improved compacity and an improved bandwidth while limiting the multiplication noise.

Abstract: An optical cavity, includes: a set of elliptical mirrors, which are intended to receive light radiation emitted by a light source, the light radiation leaving the elliptical mirrors being intended to he received by a detector; a first common focal point and a second common focal point, which are shared by the set of the elliptical mirrors, the light source being intended to he arranged at the first common focal point, the detector being intended to be arranged at the second common focal point; a contour, comprising a part formed by the set of the elliptical mirrors which are arranged consecutively.

Abstract: An optical device including a waveguide microresonator, laid out to guide a light beam along a closed loop optical path; and at least one injection and/or extraction waveguide, optically coupled to the microresonator for injection and/or extraction of the light beam. The microresonator is composed of a plurality of elementary waveguides with a spacing between them, and located one after the other to form a loop-shaped layout. Among other things, the invention increases the sensitivity of the microresonator to the surrounding medium.

Abstract: An object of the invention is an image sensor comprising a matrix of pixels, extending along a detection plane, and configured to form an image of an incident light wave propagating in a spectral band along a propagation axis, the image sensor being characterized in that it comprises a mask, formed by opaque elementary masks, extending parallel to the detection plane, between which there extend openings through which the incident light wave can propagate toward the detection plane, the matrix of pixels being divided into: open pixels extending facing the openings; masked pixels, each masked pixel being defined by a projection of an elementary mask along the axis of propagation on the matrix of pixels, each masked pixel being associated with the elementary mask facing it; the image sensor comprising, between the open pixels and the openings: a waveguide, extending facing masked pixels and open pixels; a first diffraction grating, extending facing at least one open pixel, and configured to couple part of t

Abstract: An optical coupling device including, in sequence, a focusing lens and an optical coupling network, the coupling device being symmetric with respect to a plane, the focusing lens formed in a core layer, as a front face, perpendicular to the plane, the optical coupling network including a plurality of trenches, formed on the front face, and convex in shape, the optical coupling network including, in sequence, a first sub-network and a contiguous second sub-network, respectively delimited, by a first contour and a second contour, the first and second contours extending in a divergent manner and convergent manner respectively.

Abstract: A source (100) that includes a membrane, where the membrane includes: an emissive layer (130) including an emissive surface (131); an adaptor (121a, 121b, 121c, 121d), each adaptor (121a, 121b, 121c, 121d) facing a different section of the emissive section (131), called the emissive section (132a, 132b, 132c, 132d), and with which it forms an emissive assembly (134a, 134b, 134c, 134d) adapted to reduce the spectral extent of infrared radiation emitted by the emissive section; and a plurality of heaters (140a, 140b) for heating the emissive layer (130), the heaters (140a, 140b) being arranged so as to impose different relative temperature variations in different emissive sections (132a, 132b, 132c, 132d).