Abstract: An optical method of characterizing an object comprises providing an object to be characterized, the object having at least one nanoscale feature; illuminating the object with coherent plane wave optical radiation having a wavelength larger than the nanoscale feature; capturing a diffraction intensity pattern of the radiation which is scattered by the object; supplying the diffraction intensity pattern to a neural network trained with a training set of diffraction intensity patterns corresponding to other objects with a same nanoscale feature as the object to be characterized, the neural network configured to recover information about the object from the diffraction intensity pattern; and making a characterization of the object based on the recovered information.

Abstract: An optical method of characterizing an object comprises providing an object to be characterized, the object having at least one nanoscale feature; illuminating the object with coherent plane wave optical radiation having a wavelength larger than the nanoscale feature; capturing a diffraction intensity pattern of the radiation which is scattered by the object; supplying the diffraction intensity pattern to a neural network trained with a training set of diffraction intensity patterns corresponding to other objects with a same nanoscale feature as the object to be characterized, the neural network configured to recover information about the object from the diffraction intensity pattern; and making a characterization of the object based on the recovered information.

Abstract: A tunable metamaterial comprising a membrane on which is arranged a two-dimensional array of elements to form a metamaterial, wherein the array is subdivided into blocks of multiple elements, each block being separated from adjacent blocks by a gap to allow each block to be moveable relative to its adjacent blocks. The lattice of the metamaterial and hence its properties are tuned by inducing adjacent blocks to move away from each other or towards each other either in-plane or out-of-plane in a controllable manner in response to an electrical, thermal or optical control signal.

Abstract: A tunable metamaterial comprising a membrane on which is arranged a two-dimensional array of elements to form a metamaterial, wherein the array is subdivided into blocks of multiple elements, each block being separated from adjacent blocks by a gap to allow each block to be moveable relative to its adjacent blocks. The lattice of the metamaterial and hence its properties are tuned by inducing adjacent blocks to move away from each other or towards each other either in-plane or out-of-plane in a controllable manner in response to an electrical, thermal or optical control signal.

Abstract: A non-linear optical device comprising a non-linear element made of a plasmonic material with a periodic structure having a period smaller than the wavelength of a non-linear process intrinsic to the plasmonic material. The plasmonic material is implemented as a gold film which is structured with a periodic array of asymmetric split ring slits. The metamaterial framework of the plasmonic material itself is used as the source of a strong and fast non-linearity. The cubic non-linear response is resonantly enhanced through the effect of the metamaterial structuring by more than two orders of magnitude and its sign and magnitude can be controlled by varying the metamaterial pattern.

Abstract: A method and a device are disclosed for changing the color of a metal surface in a given part of the electromagnetic spectrum. It is achieved by creating a surface relief as an array of raised or indented repeated elements without breaking the continuity of the metal surface. The characteristic size of the elements is smaller than the shortest wavelength in that part of spectrum. In particular, the method uses excitation of surface plasmons on the metal surface. The relief may be optionally covered by a layer of dielectric or semiconductor for further fixed or externally controlled change of the metal surface color. The device may be used to detect the intensity or color or phase of incident light. It may be used to detect another substance in proximity of the surface by changing the color or phase or intensity of reflected light.