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 method of imaging comprises: generating a superoscillatory field from coherent electromagnetic radiation; placing an object in the superoscillatory field; detecting one or more intensity distributions of the superoscillatory field scattered by the object; and determining at least one characteristic of the object from the one or more intensity distributions.

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 method of determining a displacement comprises: generating an interferometric superoscillatory field from coherent electromagnetic radiation, the interferometric superoscillatory field comprising an interference pattern between a reference field and a superoscillatory field; detecting with a detector a first set of intensity distributions of the interferometric superoscillatory field, each intensity distribution from a different polarisation state of the electromagnetic radiation; detecting with the detector a second set of intensity distributions of the interferometric superoscillatory field, each intensity distribution from the same polarisation states of the electromagnetic radiation as the first set of intensity distributions; extracting a first local wavevector distribution from the first set of intensity distributions and a second local wavevector distribution from the second set of intensity distributions; comparing the first local wavevector distribution and the second local wavevector distribution

Abstract: A method of determining a displacement comprises: generating an interferometric superoscillatory field from coherent electromagnetic radiation, the interferometric superoscillatory field comprising an interference pattern between a reference field and a superoscillatory field; detecting with a detector a first set of intensity distributions of the interferometric superoscillatory field, each intensity distribution from a different polarisation state of the electromagnetic radiation; detecting with the detector a second set of intensity distributions of the interferometric superoscillatory field, each intensity distribution from the same polarisation states of the electromagnetic radiation as the first set of intensity distributions; extracting a first local wavevector distribution from the first set of intensity distributions and a second local wavevector distribution from the second set of intensity distributions; comparing the first local wavevector distribution and the second local wavevector distribution

Abstract: A super-oscillatory lens (10) having a pre-defined pattern to spatially modulate the light beam in amplitude and/or phase which has a blocking element (6) formed integrally with the lens, or as a separate component adjacent to the lens, which is opaque to the light beam to cause diffraction of the light beam around the blocking element and formation of a shadow region (20). The lens and blocking element focus the light beam to form an elongate needle-shaped focus (15) in the shadow region (20). In any application in which it is necessary to scan a small spot over a surface, compared with a conventional objective lens focus the elongate shape of the focus relaxes the requirement on a feedback loop to maintain a constant separation between a scan head and a surface being scanned. The elongate shape is also ideal shape for materials processing applications.

Abstract: First and second coherent light beams of the same wavelength are propagated in opposite directions to interact on a sub-wavelength thickness metallic metamaterial layer which is structured with a periodicity such that there is a resonance matched to the wavelength of the coherent beams. The first beam is then able to modulate the intensity of the second beam by modulating the phase and/or intensity of the first beam. The interference of the counter- propagating beams can eliminate or substantially reduce Joule loss of light energy in the metamaterial layer or, on the contrary, can lead to a near total absorption of light, depending on the mutual phase and/or intensity of the interacting beams. A modulation is thus provided without using a non-linear effect.

Abstract: An imaging apparatus is disclosed which uses a super-oscillatory lens to obtain sub-diffraction limit resolution. The super-oscillatory lens is arranged to receive a light beam from a light source, the lens having a pre-defined pattern to spatially modulate the light beam in amplitude and/or phase so that it focuses the light beam to a focus at a first focal point having a full width half maximum of less than half the wavelength. Collection optical elements are arranged to focus the first focal point to a second focal point conjugate to the first focal point. An object for imaging is scanned over the first focal point and a detector is arranged to collect light from a collection region centered on the second focal point.

Abstract: First and second coherent light beams of the same wavelength are propagated in opposite directions to interact on a sub-wavelength thickness metallic metamaterial layer which is structured with a periodicity such that there is a resonance matched to the wavelength of the coherent beams. The first beam is then able to modulate the intensity of the second beam by modulating the phase and/or intensity of the first beam. The interference of the counter- propagating beams can eliminate or substantially reduce Joule loss of light energy in the metamaterial layer or, on the contrary, can lead to a near total absorption of light, depending on the mutual phase and/or intensity of the interacting beams. A modulation is thus provided without using a non-linear effect.

Abstract: A super-oscillatory lens (10) having a pre-defined pattern to spatially modulate the light beam in amplitude and/or phase which has a blocking element (6) formed integrally with the lens, or as a separate component adjacent to the lens, which is opaque to the light beam to cause diffraction of the light beam around the blocking element and formation of a shadow region (20). The lens and blocking element focus the light beam to form an elongate needle-shaped focus (15) in the shadow region (20). In any application in which it is necessary to scan a small spot over a surface, compared with a conventional objective lens focus the elongate shape of the focus relaxes the requirement on a feedback loop to maintain a constant separation between a scan head and a surface being scanned. The elongate shape is also ideal shape for materials processing applications.

Abstract: A metallic ring is made of two metals, wherein one metal forms a major arcuate portion and the other a minor arcuate portion of the ring, thereby forming a thermocouple-type structure as a result of the two inter-metallic junctions. The metallic ring supports a surface plasmon whose energy is matched to the energy, i.e. wavelength, of an incident light beam so that the oscillating electromagnetic field of the light resonates with the plasmon. The resonating plasmon causes a temperature difference to arise between the two inter-metallic junctions in the ring. The different Seebeck coefficients of the two metals results in the temperature difference causing a net current to flow around the ring, which in turn generates a magnetic field. Such a thermoelectric metamaterial ring transforms high frequency optical energy into long duration magnetic radiation pulses in the terahertz range.

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: An imaging apparatus is disclosed which uses a super-oscillatory lens to obtain sub-diffraction limit resolution. The super-oscillatory lens is arranged to receive a light beam from a light source, the lens having a pre-defined pattern to spatially modulate the light beam in amplitude and/or phase so that it focuses the light beam to a focus at a first focal point having a full width half maximum of less than half the wavelength. Collection optical elements are arranged to focus the first focal point to a second focal point conjugate to the first focal point. An object for imaging is scanned over the first focal point and a detector is arranged to collect light from a collection region centered on the second focal point.

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: An optically responsive variable reflecting surface uses a body of gallium held at a temperature slightly below its bulk melting point. Irradiation of the surface with optical energy produces substantial changes in surface reflectance. Devices employing gallium may be used for switching optical waveguides and in control of lasers.