Abstract: A multi-spectral light-field device, including an imaging component, arranged to image a light-field emitted by an object point of an object and for setting an input signal including a range of incidence angles on an optical filter. The optical filter has a transmission function depending on the incidence angles to transform the input signal into an output signal including a spectral distribution associated to an angular distribution. A micro-lens array is arranged to transform the spectral distribution of the output signal into a spatial distribution on an image plane. This multi-spectral light-field device is adapted to be integrated in a small, compact and/or handheld device, as a smartphone and also to deliver high resolution images. Also an imaging system which is a compact twin camera device. Also an object identification system allowing an image reconstruction in real-time on limited computational resources of a mobile device, by using a machine-learning module.

Abstract: A nano-structured optical wavelength transmission filter is provided. The optical filter includes a patterned substrate on which a high refractive index dielectric waveguide is arranged. A low index dielectric layer is arranged on the high refractive index dielectric waveguide, on which an array of metallic nanostructures is arranged. The layers of the optical filter have conformal shapes defined by a patterned surface of the substrate. An optical filter system includes the optical transmission filter and a detector array fixed to the substrate. A spectrometer includes at least one optical transmission filter and/or at least one said optical transmission filter system, and has a spectral resolution of lower than 30 nm for incident light having a wavelength between 300 nm and 790 nm. A method of fabrication of an optical filter, an optical filter system and a spectrometer is also described.

Abstract: A translucent construction element comprising a layer of translucent substrate, which contains a surface structured with nanoplanes of inclined angle relative to the substrate plane, and coated with an interrupted metallic layer covering at least a part of said nanoplanes, is characterized by a high density of interruptions in the metallic layer of low thickness; the periodicity of interruptions in the metallic layer generally is from the range 50 to 1000 nm and the thickness of the metallic layer typically is from the range 1 to 50 nm. The construction element may be integrated, for example, into windows, plastic films or sheets or glazings, especially for the purpose of light management.

Abstract: An ultra-thin spectrometer is disclosed for measuring spectra of a sample, including an optical layer including micro-optical elements having each an input acceptance cone of is less than 30°. At least one of the micro-optical elements is configured to provide a deflected light beam that is directed onto at least one of the photodetectors; The spectrometer includes least one continuous-shaped narrow spectral band filter element arranged between the array of micro-optical elements and the plurality of photodetectors, and defines a plurality of different filter portions that have different peak transmission wavelengths for each of the deflected light beams. The spectral resolution of the spectrometer, in its whole spectral width, is less than 50 nm. Also disclosed is a method to determine the spectrum of an incident light beam on the spectrometer.

Abstract: An angle-stable, miniaturized and integrate-able imaging system based on plasmon resonances or dielectric resonances for multispectral imaging maintaining full spatial resolution of the image sensor. Active tunability of the filter allows color recording, estimation of unknown spectra and determination of spectral singularities, for example laser lines, with the use of a conventional B/W camera. The system is characterized by high angular acceptance, cost-efficient fabrication and ease-of-use. This system can be used in conjunction with other commercial multispectral imaging systems such as RGB cameras to further enhance the spectral resolution. It can be adapted to different spectral ranges, depending on the application.

Abstract: A nano-structured optical wavelength transmission filter is provided. The optical filter includes a patterned substrate on which a high refractive index dielectric waveguide is arranged. A low index dielectric layer is arranged on the high refractive index dielectric waveguide, on which an array of metallic nanostructures is arranged. The layers of the optical filter have conformal shapes defined by a patterned surface of the substrate. An optical filter system includes the optical transmission filter and a detector array fixed to the substrate. A spectrometer includes at least one optical transmission filter and/or at least one said optical transmission filter system, and has a spectral resolution of lower than 30 nm for incident light having a wavelength between 300 nm and 790 nm. A method of fabrication of an optical filter, an optical filter system and a spectrometer is also described.

Abstract: In the present invention a new atomic clock is proposed comprising: at least one light source adapted to provide an optical beam, at least one photo detector and a vapor cell comprising a first optical window, said optical beam being directed through said vapor cell for providing an optical frequency reference signal, said photo detector being adapted to detect said optical frequency reference signal and to generate at least one reference signal, wherein—said atomic clock comprises a first optical waveguide arranged to said first optical window, said first optical waveguide being arranged to incouple at least a portion of said optical beam, said first optical waveguide being sized and shaped so that said first guided light beam is expanded, a first outcoupler is arranged to outcouple at least a portion of said guided light beam to said vapor cell, —the thickness t of the atomic clock is smaller than 15 nm.

Abstract: An angle-stable, miniaturized and integrate-able imaging system based on plasmon resonances or dielectric resonances for multispectral imaging maintaining full spatial resolution of the image sensor. Active tunability of the filter allows color recording, estimation of unknown spectra and determination of spectral singularities, for example laser lines, with the use of a conventional B/W camera. The system is characterized by high angular acceptance, cost-efficient fabrication and ease-of-use. This system can be used in conjunction with other commercial multispectral imaging systems such as RGB cameras to further enhance the spectral resolution. It can be adapted to different spectral ranges, depending on the application.

Abstract: An imaging system suitable to provide an image of a surface portion of an object is disclosed. The system includes a light source arranged to provide a light beam, at least a first optical waveguide having a first face and having a second face opposite to the first face, the first face having an incoupling surface. The optical waveguide includes an outcoupling surface, a first diffraction grating arranged on the optical waveguide, and an imaging subsystem arranged to the outcoupling surface. The first diffraction grating is arranged to outcouple at least a fraction of the light beam.

Abstract: A translucent or transparent film or sheet device shows angular-independent IR reflectance, which comprises a substrate (1) covered with a layer of a dielectric high refractive index material (4) containing a thin metallic layer (3) embedded in said material, and a further layer (5) of translucent or transparent material covering said layer (4) of dielectric high refractive index material, characterized in that the embedded metal layer (3) is periodically interrupted with a periodicity of 50 to 800 nm such that metal covers at least 70% of the substrate area. The device may advantageously be integrated into a window, a glass facade element or especially onto a photovoltaic (PV) device, where it reduces the fraction of IR radiation passing into the building, or reduces heat take-up and thus lowers the operating temperature and improves the efficiency of the PV cell.

Abstract: An imaging system suitable to provide an image of a surface portion of an object is disclosed. The system includes a light source arranged to provide a light beam, at least a first optical waveguide having a first face and having a second face opposite to the first face, the first face having an incoupling surface. The optical waveguide includes an outcoupling surface, a first diffraction grating arranged on the optical waveguide, and an imaging subsystem arranged to the outcoupling surface. The first diffraction grating is arranged to outcouple at least a fraction of the light beam.

Abstract: In the present invention a new atomic clock is proposed comprising: at least one light source adapted to provide an optical beam, at least one photo detector and a vapor cell comprising a first optical window, said optical beam being directed through said vapor cell for providing an optical frequency reference signal, said photo detector being adapted to detect said optical frequency reference signal and to generate at least one reference signal, wherein—said atomic clock comprises a first optical waveguide arranged to said first optical window, said first optical waveguide being arranged to incouple at least a portion of said optical beam, said first optical waveguide being sized and shaped so that said first guided light beam is expanded,—a first outcoupler is arranged to outcouple at least a portion of said guided light beam to said vapor cell,—the thickness t of the atomic clock is smaller than 15 mm.

Abstract: The invention concerns a photoelectric conversion device comprising: at least one photoconversion element comprising at least one organic photoconversion layer or an inorganic layer comprising quantum dots or perovskites; at least a first grating structure arranged on a first side of the photoconversion element; and at least a second grating structure arranged on a second side of the photoconversion element; wherein said at least a first grating structure is arranged so as to direct a near-infra-red light portion of light incident on said first grating structure into said photoconversion element, the said at least a second grating structure being arranged to reflect at least a part of said near-infra-red light portion back into said photoconversion element and to pass visible light out of the photoelectric conversion device.

Abstract: A translucent construction element comprising a layer of translucent substrate, which contains a surface structured with nanoplanes of inclined angle relative to the substrate plane, and coated with an interrupted metallic layer covering at least a part of said nanoplanes, is characterized by a high density of interruptions in the metallic layer of low thickness; the periodicity of interruptions in the metallic layer generally is from the range 50 to 1000 nm and the thickness of the metallic layer typically is from the range 1 to 50 nm. The construction element may be integrated, for example, into windows, plastic films or sheets or glazings, especially for the purpose of light management.