The invention concerns a method of manufacturing a modulated optically diffractive grating and a corresponding grating. The method comprises providing a substrate and manufacturing a plurality of temporary elements onto the substrate, the temporary elements being arranged in a periodic pattern comprising at least two periods having different element characteristics. Next, a first deposition layer is deposited so as to at least partially cover the temporary elements with the first deposition layer and the temporary elements are removed from the substrate in order to form onto the substrate a modulated diffractive grating of first grating elements made of the first deposition layer, the pattern comprising within each period a plurality of first grating elements and one more gaps between the first grating elements. The invention allows for producing high-quality gratings with locally varying diffraction efficiency.

The system and method includes the suspension of a free-standing carbon article within a reaction chamber, the introduction of the chemical precursor in a reaction environment within the chamber, and heating of the carbon article in the presence of the chemical precursor leading to deposition in a site-specific manner.

The system and method includes the suspension of a free-standing carbon article within a reaction chamber, the introduction of the chemical precursor in a reaction environment within the chamber, and heating of the carbon article in the presence of the chemical precursor leading to deposition in a site-specific manner.

A SiC film structure for obtaining a three-dimensional SiC film by forming the SiC film in an outer circumference of a substrate using a vapor deposition type film formation method and removing the substrate, the SiC film structure including: a main body having a three-dimensional shape formed of a SiC film and having an opening for removing the substrate; a lid configured to cover the opening; and a SiC coat layer configured to cover at least a contact portion between the main body and an outer edge portion of the lid and join the main body and the lid.

A SiC film structure for obtaining a three-dimensional SiC film by forming the SiC film in an outer circumference of a substrate using a vapor deposition type film formation method and removing the substrate, the SiC film structure including: a main body having a three-dimensional shape formed of a SiC film and having an opening for removing the substrate; a lid configured to cover the opening; and a SiC coat layer configured to cover at least a contact portion between the main body and an outer edge portion of the lid and join the main body and the lid.

A non-planar chemical vapour deposition polycrystalline diamond body has a dome body having an apex and an outer periphery. The dome body has an average radius of curvature in a range of 4 mm to 25 mm and a maximum linear dimension at the outer periphery of the dome body of no more than 26 mm. The average radius of curvature is no less than 0.6 times the maximum linear dimension at the outer periphery. A method of fabricating the non-planar diamond body is also disclosed.

A non-planar chemical vapour deposition polycrystalline diamond body has a dome body having an apex and an outer periphery. The dome body has an average radius of curvature in a range of 4 mm to 25 mm and a maximum linear dimension at the outer periphery of the dome body of no more than 26 mm. The average radius of curvature is no less than 0.6 times the maximum linear dimension at the outer periphery. A method of fabricating the non-planar diamond body is also disclosed.

The method includes forming an inner monolithic layer from crystals of beta phase stoichiometric silicon carbide on a carbon substrate in the form of a rod by chemical methylsilane vapor deposition in a sealed tubular hot-wall CVD reactor. The method further includes forming a central composite layer over the inner monolithic layer by twisting continuous beta phase stoichiometric silicon carbide fibers into tows, transporting the tows to a braiding machine, and forming a reinforcing thread framework. A pyrocarbon interface coating is built up by chemical methane vapor deposition in a sealed tubular hot-wall CVD reactor. Then, a matrix is formed by chemical methylsilane vapor deposition in the reactor. A protective outer monolithic layer is formed from crystals of beta phase stoichiometric silicon carbide over the central composite layer by chemical methylsilane vapor deposition in a CVD reactor. And then the carbon substrate is removed from the fabricated semi-finished product.

The method includes forming an inner monolithic layer from crystals of beta phase stoichiometric silicon carbide on a carbon substrate in the form of a rod by chemical methylsilane vapor deposition in a sealed tubular hot-wall CVD reactor. The method further includes forming a central composite layer over the inner monolithic layer by twisting continuous beta phase stoichiometric silicon carbide fibers into tows, transporting the tows to a braiding machine, and forming a reinforcing thread framework. A pyrocarbon interface coating is built up by chemical methane vapor deposition in a sealed tubular hot-wall CVD reactor. Then, a matrix is formed by chemical methylsilane vapor deposition in the reactor. A protective outer monolithic layer is formed from crystals of beta phase stoichiometric silicon carbide over the central composite layer by chemical methylsilane vapor deposition in a CVD reactor. And then the carbon substrate is removed from the fabricated semi-finished product.

A method includes providing a coating over a surface of a substrate, a plurality of seed structures being disposed on the surface of the substrate, in which respective heights of the seed structures define local thicknesses of the coating. An optical device includes a substrate, a plurality of seed structures on a surface of the substrate, and a coating on the seed structures and on the surface of the substrate, in which respective heights of the seed structures define local thicknesses of the coating.