Abstract: Apparatus for use in four wave mixing is disclosed, comprising a nonlinear medium for receiving a plurality of light beams copropagating along an optical path through the nonlinear medium, the plurality of light beams including at least one signal wave having a signal frequency and one or two pump waves having respective pump frequencies, the light beams generating one or more unwanted idler waves in the nonlinear medium. The apparatus further comprises phase adjusting means arranged to selectively apply to wavelengths of light in the nonlinear medium, respective wavelength-dependent phase shifts to adjust the phase difference between the or each pump wave and the signal wave, such that unwanted idler waves are generated along the optical path of the nonlinear medium so as to destructively interfere, suppressing unwanted idler waves at an output of the nonlinear medium. A method of configuring the phase adjusting means is disclosed.

Abstract: The invention is that of an encapsulated electronic component assembly that may be incorporated into a textile or yarn. Electronic components is encapsulated in two flexible substrates forming a pod for housing the electronic components. A flexible substrate may be a flexible polymer film capable of compression in response to a bending force, protecting the internal electronic components. The components in the substrate may then be incorporated into a yarn or woven into a textile. The electronic components may comprise an antenna, data processor, light emitter, accelerometer, or other components.

Abstract: A method of fabricating an optical element includes providing a substrate of a transparent material in which is to be formed a plurality of birefringent nanostructures spaced apart; generating from the output of a source of femtosecond laser pulses a laser beam group comprising a plurality of focused seeding beams having a circular polarisation; directing the laser beam group onto the surface of the substrate at a first position and applying one or more femtosecond laser pulses from each beam to corresponding volumes in the substrate; repeatedly translating the laser beam group relative to the substrate parallel to the line of seeding beams; translating the laser beam group relative to the substrate and repeating the repeated translation and application of the femtosecond laser pulses; wherein the relative translation of the laser beam group and the substrate aligns the writing beam with successive corresponding volumes.

Abstract: A sensor system includes a radiation source, an optical fiber, and a detection device. The radiation source is arranged to emit pulses of radiation. The optical fiber comprises a first end and a core. The first end is arranged to receive pulses of radiation output from the radiation source such that, in use, the pulses of radiation are coupled into the fiber. The core is arranged to support propagation of the pulses of radiation along the fiber. The core includes a plurality of reflectors each comprising a portion of the core having a refractive index which is different to the refractive index of adjacent regions of the core. Reflections of a pulse of radiation from adjacent reflectors output at the first end of the fiber are resolvable from each other in the time domain. The detection device is arranged to measure radiation output from the first end of the fiber and resolve radiation reflected at different locations in the core of the fiber.

Abstract: There is provided a method of identifying one or more substances in a sample by: illuminating the sample with light of each of a plurality of different excitation modes; measuring an intensity and/or polarisation of light from the sample at a plurality of wavelengths to obtain a measured spectrum for each of the excitation modes; and identifying one or more substances in the sample using the measured spectra together, wherein: the excitation modes differ in one or both of wavelength and polarisation; and the identifying of the one or more substances uses contributions to the measured spectra from a plurality of photophysical processes in the sample including inelastic scattering of light. An apparatus suitable for carrying out the method is also provided.

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: A method for obtaining chemical and/or material specific information of a sample based on scattered light. The method comprises receiving detection data comprising at least two images. Each image is indicative of the intensity of scattered light i) for incident light of a different wavelength, or ii) for incident light of a different polarization state, or iii) of a different polarization state. The scattered light comprises an elastic scattering component that is due to Rayleigh scattering of the incident light in at least a portion of the sample. Alternatively, each image is indicative of the intensity of scattered light i) of a different wavelength, or ii) for incident light of a different polarization state, or iii) of a different polarization state, wherein the scattered light comprises an inelastic scattering component that is due to Raman scattering of the incident light in at least a portion of the sample.

Abstract: A method of manufacturing a photonic chip. The method comprises providing a wafer comprising a silicon substrate, and a low refractive index layer above the silicon substrate, forming a first trench having a first height and a second trench having a second height by etching the low refractive index layer. The second height is greater than the first height and the second trench has a bottom surface that is closer to the substrate than a bottom surface of the first trench.

Abstract: An optical source comprises: a pump source operable to generate laser light at a first wavelength; a single mode optical fibre arranged to receive laser light at the first wavelength from the pump source, the optical fibre being fabricated from material having a Raman gain profile for stimulated Raman scattering of light at the first wavelength, and a Brillouin gain profile for stimulated Brillouin scattering of light at the second wavelength to a third wavelength longer than the second wavelength; and a superstructured fibre Bragg grating formed in the optical fibre, the grating comprising: a periodic refractive index profile along a core of the optical fibre, giving transmission of the first wavelength to allow received laser light at the first wavelength to enter the superstructured fibre Bragg grating, reflection of the second wavelength at a first level, and reflection of the third wavelength at a second level lower than the first level; and a phase shift at an intermediate location along a length of the

Abstract: An anti-resonant hollow-core fiber comprising a first tubular, cladding element which defines an internal cladding surface, a plurality of second tubular elements which are attached to the cladding surface and together define a core with an effective radius, the second tubular elements being arranged in spaced relation and adjacent ones of the second tubular elements having a spacing therebetween, and a plurality of third tubular elements, each nested within a respective one of the second tubular elements.

Abstract: An optical trap for laser cooling and trapping atoms. Three pairs of laser beams are directed to cross in a vacuum chamber at a common intersection volume, wherein each pair is formed by two counterpropagating beams. Rather than having a mutually orthogonal arrangement in which each beam pair forms an angle ? of 45° to a reference axis, z, these angles are instead between 5°???40°. Moreover, in each beam pair, the counterpropagating beams are not precisely aligned in a common path, as in a conventional magneto-optical trap, but are slightly misaligned by respective misalignment angles [?, ?, ?] of typically 0.1° to 2°. The misalignment angles and beam widths are however selected so that a common intersection volume for all six beams is maintained. This provides an all-optical trap in which laser cooling and trapping of atoms takes place without a magnetic field being present.

Abstract: A method of antimicrobial susceptibility testing comprises: preparing samples of microorganisms suspended in an electrolyte, comprising a first sample of the microorganisms unexposed to antimicrobial agents and a second sample of the microorganisms exposed to an antimicrobial agent; passing the first sample through an impedance flow cytometer to obtain a first impedance signal representing one or more components of impedance values of the unexposed microorganisms; passing the second sample through the impedance flow cytometer to obtain a second impedance signal representing one or more components of the impedance values of the exposed microorganisms; comparing the first impedance signal and the second impedance signal; and determining a susceptibility of the microorganisms to the antimicrobial agent based on any differences between the first impedance signal and second impedance signal.

Abstract: The invention provides cyclic peptides that are able to disrupt the typical response to hypoxia and which have particular utility in the treatment of cancers and von Hippel-Lindau disease.

Abstract: A method of delivering optical pulses to a substrate comprises directing a focused beam from a source of optical pulses along a propagation direction onto a substrate; moving the substrate relative to the beam in a plane substantially orthogonal to the propagation direction and continuously along a first direction that includes spaced apart row locations on the substrate, and delivering a plurality of optical pulses from source as the beam reaches each row location; and between delivering the optical pulses at consecutive row locations, moving the beam relative to the substrate in one or more successive discrete movements along a second direction in the plane orthogonal to the first direction, to direct the beam to one or more spaced apart column locations on the substrate, and delivering a plurality of optical pulses from the source at each column location.

Abstract: Impedance flow cytometry apparatus comprises: a flow channel for carrying a flow of fluid comprising particles suspended in an electrolyte from an inlet to an outlet; a first electrode group and a second electrode group, each electrode group providing first and second current paths through fluid flowing in the flow channel; wherein each electrode group comprises: a first signal electrode to provide to the first current path a first electrical signal of frequency, magnitude and phase; a second signal electrode to provide to the second current path a second electrical signal of substantially equal frequency and magnitude as the first electrical signal and of opposite phase to the first electrical signal; and one or more measurement electrodes to detect current flow in the first current path and the second current path and produce a summed signal representing the sum of the current flow in the first current path and the current flow in the second current path; wherein the first electrode group produces a first s

Abstract: The present invention is related to compounds, methods, compositions and uses that are able to restore responsiveness to immunotherapy, in particular immune check point inhibitors or anti-cancer vaccine or to anti-angiogenesis treatment.

Abstract: A method of making an optical fibre preform comprising providing a hollow outer tube of glass, providing a hollow primary capillary tube of glass with an outer diameter smaller than an inner diameter of the outer tube, positioning the primary capillary tube inside the outer tube such that an outer surface of the primary capillary tube lies against an inner surface of the outer tube along a contact line parallel to the longitudinal axes of the primary capillary tube and the outer tube, and bonding the primary capillary tube into its position inside the outer tube by directing a laser beam onto a surface of the outer tube or the primary capillary at one or more locations aligned with the contact line.

Abstract: A method for fabricating an optical waveguide comprises: providing a sample of lithium niobate doped with magnesium oxide and having at least one grating of periodic domain inversion defined therein; applying a layer of metallic zinc to a surface of the sample over the at least one grating using sputter deposition; heating the sample in an atmosphere of pure oxygen to cause the zinc to indiffuse into the lithium niobate to form a waveguiding layer of increased refractive index under the surface of the sample; and using a dicing blade to cut two substantially parallel channels along a length direction of the at least one grating, to define a ridge waveguide between the two channels.

Abstract: A method of impedance flow cytometry comprises: flowing a fluid along a flow channel; applying electrical signals to current paths through the fluid, the current paths comprising at least first and second current paths, and further first and second current paths, wherein the electrical signals applied to the first and further first current paths have a frequency, magnitude and phase, and the electrical signals applied to the second and further second current paths have substantially equal frequency and magnitude and opposite phase to the electrical signals applied to the first and first further current path; detecting current flow in the current paths; producing a first summed signal representing the sum of the current flows detected in the current paths, and a second summed signal representing the sum of the current flows detected in the further current paths; and obtaining a differential signal representing the difference between the summed signals.

Abstract: A method of making an optical fibre preform comprising providing a hollow outer tube of glass, providing a hollow primary capillary tube of glass with an outer diameter smaller than an inner diameter of the outer tube, positioning the primary capillary tube inside the outer tube such that an outer surface of the primary capillary tube lies against an inner surface of the outer tube along a contact line parallel to the longitudinal axes of the primary capillary tube and the outer tube, and bonding the primary capillary tube into its position inside the outer tube by directing a laser beam onto a surface of the outer tube or the primary capillary at one or more locations aligned with the contact line.