Abstract: The present invention relates to a method for producing a timepiece comprising at least one first part produced by a microfabrication or microforming method in at least one first material, said method comprising at least: a step of depositing, on said first part, without moulding, at least one second part of said timepiece in at least one second material, and a step of treating the second material in order to connect together the components on the first part.

Abstract: The invention relates to a grating coupler comprising: —an optical substrate arranged to transfer a light beam, and—a diffraction grating arranged on, or imbedded in, the surface of said optical substrate, said diffraction grating comprising diffraction grating elements comprising each a coating arranged asymmetrically on said diffraction grating elements. The grating coupler is further arranged to satisfy the condition: (n1×sin(I?I)+?2)/?×P>1, wherein n1 is the refractive index of the optical medium to the incident light side of the diffraction grating elements, n2 is the refractive index of the optical medium to the diffracted light side of the diffraction grating elements, lal the absolute value of the incident angle of the light beam incident on the grating coupler ? is the vacuum wavelength of the diffracted light, and P is the period of the diffraction grating elements.

Abstract: A tamper seal includes an optical waveguide arranged to guide a propagating light-beam along a propagation direction. First and second portions of the tamper seal are configured to be arranged on first and second parts, respectively, of an object, said first and a second parts being movable relative to each other. The first portion comprises an input coupler arranged to couple incident light into said optical waveguide. The second portion includes at least one outcoupling surface arranged to couple out at least partially light guided in the optical waveguide. The input coupler, optical waveguide and outcoupling surface are arranged to transmit light from the input coupler to the outcoupling surface. The optical waveguide is further designed to be at least partially disruptable between the two portions, wherein the optical waveguide loses or at least partially changes its optical guiding properties after its disruption.

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 diffractive optical filter comprises a bulk material (1) having a first refractive index, a volume diffraction grating structure (2,3) having a second, different, refractive index embedded in the bulk material (1), and a mirror (4) formed within or on the surface of the bulk material (1) behind the grating structure (2,3). By placing the mirror (4) immediately behind the grating structure (2,3) the diffractive structure is effectively doubled and consequently the number of effective optically active layer is doubled. Such diffractive optical filters may be used as diffractive identification devices bonded to articles whose authenticity needs to be established.