Abstract: The invention relates to methods and systems for measuring optical characteristics of objects, particularly for measuring birefringence of objects. The method comprises directing a uniformly polarised measurement beam onto an object: rotating the state of polarisation of the measurement beam automatically with holograms: detecting polarisation properties of the measurement beam without interacting with the object and after interacting with the object for each state of polarisation of the measurement beam; and using the detected polarization properties of the measurement beam without interacting with the object and after interacting with the object for each the state of polarisation to determine a measurement of birefringence of the object.

Abstract: A powered air purifying respirator (PARR) has a yoke and a pump. The yoke defines an air inlet and an air outlet fluidly connected via an air flow passage. The pump is disposed within an interior of the yoke and is configured to pump air from the air inlet to the air outlet via the air flow passage. The yoke is shaped to fit around the user's neck and be supported by the user's shoulders. A hood for a PARR has a head portion configured to receive a user's head, and a one-way exhaust valve configured to vent air from an internal environment of the hood to an environment external to the hood. The hood is configured to receive a yoke of the PARR.

Abstract: Aspects of the present disclosure include a water filter mount for a beverage dispenser. The water filter mount releasably mounts a water filter to the beverage dispenser using a rotating motion that does not require any tools. Aspects of the present disclosure also include a gas cylinder mount for a beverage dispenser. The gas cylinder mount releasably mounts a water filter to the beverage dispenser using a rotating motion that does not require any tools. Aspects of the present disclosure also include a concentrate vial mount for a beverage dispenser. The concentrate vial releasably mounts a water filter to the beverage dispenser using a rotating motion that does not require any tools.

Abstract: A respirator for filtering respirated air by covering a nose area to a jaw area of a user is disclosed. The respirator includes a mask body with a front mouth panel and an upper rear nose panel. The mouth panel having a front panel outer portion and a front panel fold portion. The upper nose panel having an upper nose panel fold portion and an upper nose panel free portion. A juncture of the upper nose panel fold portion and the front panel fold portion being a movable fold. The movable fold being upwardly movable between a closed mouth position and an open mouth position, an edge spacing between an upper mask edge and an upper mouth panel edge being greater in the open mouth position than in the closed mouth position.

Abstract: This invention relates generally to a method and system for hybrid classical-quantum communication. The method comprises transmitting a single photon having a particular quantum state over a communication medium using a quantum mode set; and transmitting a classical light beam over the same communication medium using a classical mode set, wherein the classical and quantum mode sets comprise non-separable modes in common. The non-separable modes in common may be two degrees of freedom of a single photon or classical light and may thus be spatial modes in one or more indexes, and polarisation. The invention relates also to a system to implement the method accordingly.

Abstract: The invention relates to optical communication methods and systems. In particular, the invention relates to an optical communication method and system which is configured to create a multiplexed beam from an incident beam, wherein the multiplexed beam comprises a predetermined number of spatial modes simultaneously generated and multiplexed together in a fashion that is independent of wavelength. The spatial modes have two degrees of spatial freedom. The multiplexed beam is de-multiplexed downstream from multiplexing thereof in the communication system in a simultaneous fashion independent of wavelength to yield the predetermined number of spatial mode. The modes are used in optical communication as channels or as bits in a bit (de) encoding scheme.

Abstract: This invention relates to a method of and a system for determining a beam quality factor (VQF) of a beam of light having a transverse electric field that may be scalar, vector, or a combination thereof, wherein the VQF is a measure of the degree of vectorness of the beam of light varying between pure scalar and pure vector. The beam is typically a laser beam, wherein the method comprises receiving an input laser beam to be analysed and splitting the received beam of light into two orthogonal components. A predetermined number of modes or states per orthogonal component is then detected and an on axis intensity of each detected mode or state detected is measured. The measured intensities is then used to calculate the VQF in terms using at least one quantum mechanical entanglement measure.

Abstract: The invention relates to optical communication methods and systems. In particular, the invention relates to an optical communication method and system which is configured to create a multiplexed beam from an incident beam, wherein the multiplexed beam comprises a predetermined number of spatial modes simultaneously generated and multiplexed together in a fashion that is independent of wavelength. The spatial modes have two degrees of spatial freedom. The multiplexed beam is de-multiplexed downstream from multiplexing thereof in the communication system in a simultaneous fashion independent of wavelength to yield the predetermined number of spatial mode. The modes are used in optical communication as channels or as bits in a bit (de) encoding scheme.

Abstract: This invention relates generally to a method and system for hybrid classical-quantum communication. The method comprises transmitting a single photon having a particular quantum state over a communication medium using a quantum mode set; and transmitting a classical light beam over the same communication medium using a classical mode set, wherein the classical and quantum mode sets comprise non-separable modes in common. The non-separable modes in common may be two degrees of freedom of a single photon or classical light and may thus be spatial modes in one or more indexes, and polarisation. The invention relates also to a system to implement the method accordingly.

Abstract: This invention relates to a method of and a system for determining a beam quality factor (VQF) of a beam of light having a transverse electric field that may be scalar, vector, or a combination thereof, wherein the VQF is a measure of the degree of vectorness of the beam of light varying between pure scalar and pure vector. The beam is typically a laser beam, wherein the method comprises receiving an input laser beam to be analysed and splitting the received beam of light into two orthogonal components. A predetermined number of modes or states per orthogonal component is then detected and an on axis intensity of each detected mode or state detected is measured. The measured intensities is then used to calculate the VQF in terms using at least one quantum mechanical entanglement measure.

Abstract: An exhaled breath condensate collection device (10) is described. The device includes a condensation chamber (12) having an inlet and an outlet and arranged such that breath exhaled from the lungs of a user flows through the condensation chamber from the inlet to the outlet; at least one cooling element (16); and a frame (18) supporting the condensation chamber and the at least one cooling element. The frame (18) is movable between a first configuration in which the at least one cooling element is operable to cool the condensation chamber so as to promote the formation of breath condensate in the condensation chamber, and a second configuration in which the cooling element is displaced from the condensation chamber so as to encourage condensate to flow into a collection region in fluid communication with the condensation chamber. To be accompanied by FIG. 5.

Abstract: The invention relates to particular devices and methods for measuring commodity volume in a rail tank car. In accordance with an aspect of the present invention, the device can comprise a configuration so as to enable permanent or semi-permanent installation on a rail tank car while minimizing interference with other fittings and valves.

Abstract: Laser apparatus includes an output coupler, a gain medium for generating laser light, a rear optical element, and an input coupler. The input coupler is arranged to direct a pump beam to the gain medium and to define an optical path between the output coupler and the rear optical element. The rear optical element is a spatial light modulator arranged to act as an intra-cavity digital holographic mirror which can be digitally addressed. The spatial light modulator displays selectively a gray-scale image of a hologram thereby to phase-modulate laser light in the cavity, thus making it possible to generate an output laser beam having a desired characteristic. The apparatus includes a computer arranged to generate at least one hologram corresponding to a desired output beam characteristic, and a driver circuit responsive to an output from the computer to generate a corresponding gray-scale image of the hologram on the spatial light modulator.

Abstract: An exhaled breath condensate collection device (10) is described. The device includes a condensation chamber (12) having an inlet and an outlet and arranged such that breath exhaled from the lungs of a user flows through the condensation chamber from the inlet to the outlet; at least one cooling element (16); and a frame (18) supporting the condensation chamber and the at least one cooling element. The frame (18) is movable between a first configuration in which the at least one cooling element is operable to cool the condensation chamber so as to promote the formation of breath condensate in the condensation chamber, and a second configuration in which the cooling element is displaced from the condensation chamber so as to encourage condensate to flow into a collection region in fluid communication with the condensation chamber. To be accompanied by FIG. 5.

Abstract: A method and apparatus for performing a modal decomposition of a laser beam are disclosed. The method includes the steps of performing a measurement to determine the second moment beam size (w) and beam propagation factor (M2) of the laser beam, and inferring the scale factor (wO) of the optimal basis set of the laser beam from the second moment beam size and the beam propagation factor, from the relationship: wO=w/M2. An optimal decomposition is performing using the scale factor wO to obtain an optimal mode set of adapted size. The apparatus includes a spatial light modulator arranged for complex amplitude modulation of an incident laser beam, and imaging means arranged to direct the incident laser beam onto the spatial light modulator. Fourier transforming lens is arranged to receive a laser beam reflected from the spatial light modulator.

Abstract: The invention relates to an optical resonator, laser apparatus and a method of generating a laser beam inside an optical resonator. The optical resonator (100) includes an optical cavity (102) and an optical element (104.1, 104.2) at either end thereof, operable to sustain a light beam (108) therein, characterized in that each optical element (104.1, 104.2) is a phase-only optical element operable to alter a mode of the beam (108) as it propagates along the length of the optical resonator (100), such that in use the beam (108) at one end of the optical resonator (100) has a Gaussian profile while the beam (108) at the other end of the optical resonator (100) has a non-Gaussian profile.

Abstract: Laser apparatus includes an output coupler, a gain medium for generating laser light, a rear optical element, and an input coupler. The input coupler is arranged to direct a pump beam to the gain medium and to define an optical path between the output coupler and the rear optical element. The rear optical element is a spatial light modulator arranged to act as an intra-cavity digital holographic mirror which can be digitally addressed. The spatial light modulator displays selectively a gray-scale image of a hologram thereby to phase-modulate laser light in the cavity, thus making it possible to generate an output laser beam having a desired characteristic. The apparatus includes a computer arranged to generate at least one hologram corresponding to a desired output beam characteristic, and a driver circuit responsive to an output from the computer to generate a corresponding gray-scale image of the hologram on the spatial light modulator.

Abstract: The invention relates to an optical resonator, laser apparatus and a method of generating a laser beam inside an optical resonator. The optical resonator (10) includes an optical cavity (12) and an optical element (104.1, 104.2) at either end there-of, operable to sustain a light beam (108) therein, characterised in that each optical element (104.1, 104.2) is a phase-only optical element operable to alter a mode of the beam (108) as it propagates along the length of the optical resonator (10), such that in use the beam (108) at one end of the optical resonator (10) has a Gaussian profile while the beam (108) at the other end of the optical resonator (10) has a non-Gaussian profile.

Abstract: In order to provide a simple design of ventilation device which has a relatively open aperture of pleasing aesthetic appearance, there is provided a face 2 for facing into a room, the face including an aperture 3. Three closure parts 5 are provided for closing the aperture 3. The closure parts 5 are rotatably mounted adjacent to the aperture 3 about pivots 9 located around the periphery of the aperture. A drive means is provided for moving the closure parts between an open position and a closed position. A suitable fan 6 can be provided for drawing air through the aperture when the closure parts are in the open position. In a first aspect of the invention, the closure parts 5 each comprise closures surfaces having edges, the edges abutting one another in the closed position. In a second aspect of the invention, there is drive member 12 for contacting a drive part 11 of a closure part 5, the drive part 11 being located close to the pivot 9.