Abstract: An interferometric optical fibre sensor comprises optical fibre defining an optical circuit configured to propagate a first optical wave via an environment in which the optical fibre can be exposed to a stimulus that modifies the first optical wave, and a second optical wave, and to combine the first optical wave and the second optical wave to create an interference signal containing information about the stimulus, wherein optical fibre propagating either or both of the first optical wave and the second optical wave comprises hollow core optical fibre configured to propagate the optical wave or waves by an antiresonant optical guidance effect.

Abstract: An interferometric optical fibre sensor comprises optical fibre defining an optical circuit configured to propagate a first optical wave via an environment in which the optical fibre can be exposed to a stimulus that modifies the first optical wave, and a second optical wave, and to combine the first optical wave and the second optical wave to create an interference signal containing information about the stimulus, wherein optical fibre propagating either or both of the first optical wave and the second optical wave comprises hollow core optical fibre configured to propagate the optical wave or waves by an antiresonant optical guidance effect.

Abstract: An interferometric optical fibre sensor comprises optical fibre defining an optical circuit configured to propagate a first optical wave via an environment in which the optical fibre can be exposed to a stimulus that modifies the first optical wave, and a second optical wave, and to combine the first optical wave and the second optical wave to create an interference signal containing information about the stimulus, wherein optical fibre propagating either or both of the first optical wave and the second optical wave comprises hollow core optical fibre configured to propagate the optical wave or waves by an antiresonant optical guidance effect.

Abstract: An interferometric optical fibre sensor comprises optical fibre defining an optical circuit configured to propagate a first optical wave via an environment in which the optical fibre can be exposed to a stimulus that modifies the first optical wave, and a second optical wave, and to combine the first optical wave and the second optical wave to create an interference signal containing information about the stimulus, wherein optical fibre propagating either or both of the first optical wave and the second optical wave comprises hollow core optical fibre configured to propagate the optical wave or waves by an antiresonant optical guidance effect.

Abstract: The present disclosure provides methodologies for manufacturing photovoltaic devices. In particular, the disclosure relates to the use of hydrogen during manufacturing of photovoltaic devices for passivating defects in the silicon and addressing light-induced degradation. The methodologies in the present disclosures take advantage of generation and manipulation of hydrogen in the neutral or charged state to optimise defect passivation. Some of the methodologies disclose use thermal treatments, illumination with sub-bandgap photons, electric fields or defects in the silicon to control the state of charge or hydrogen, move hydrogen to different locations in the device or retain hydrogen at specific locations.

Abstract: The present disclosure is directed to a method for processing a silicon wafer that allows improving performance by exploiting the properties of crystallographic imperfections. The method comprises the steps of: forming a silicon layer with crystallographic imperfections in the proximity of a surface of the silicon; exposing at least a portion of the device to hydrogen atoms in a manner such that hydrogen atoms migrate towards the region with crystallographic imperfections and into the silicon along the crystallographic imperfections; and controlling the charge state of hydrogen atoms located at the crystallographic imperfections to be positive when the imperfections are in a p-type region of the wafer; and negative when the imperfections are at an n-type region of the wafer by thermally treating the silicon while exposing the silicon to an illumination intensity of less than 10 mW/cm2.

Abstract: The present disclosure is directed to a method for processing a silicon wafer that allows improving performance by exploiting the properties of crystallographic imperfections. The method comprises the steps of: forming a silicon layer with crystallographic imperfections in the proximity of a surface of the silicon; exposing at least a portion of the device to hydrogen atoms in a manner such that hydrogen atoms migrate towards the region with crystallographic imperfections and into the silicon along the crystallographic imperfections; and controlling the charge state of hydrogen atoms located at the crystallographic imperfections to be positive when the imperfections are in a p-type region of the wafer; and negative when the imperfections are at an n-type region of the wafer by thermally treating the silicon while exposing the silicon to an illumination intensity of less than 10 mW/cm2.

Abstract: The present disclosure provides methodologies for manufacturing photovoltaic devices. In particular, the disclosure relates to the use of hydrogen during manufacturing of photovoltaic devices for passivating defects in the silicon and addressing light-induced degradation. The methodologies in the present disclosures take advantage of generation and manipulation of hydrogen in the neutral or charged state to optimise defect passivation. Some of the methodologies disclose use thermal treatments, illumination with sub-bandgap photons, electric fields or defects in the silicon to control the state of charge or hydrogen, move hydrogen to different locations in the device or retain hydrogen at specific locations.

Abstract: The present disclosure provides methods for manufacturing a photovoltaic device that comprise a sequence of annealing steps and exposure to electromagnetic radiation during annealing that allow passivating electrically active defects and stabilising the performance of photovoltaic device.

Abstract: The present disclosure provides methods for manufacturing a photovoltaic device that comprise a sequence of annealing steps and exposure to electromagnetic radiation during annealing that allow passivating electrically active defects and stabilising the performance of photovoltaic device.

Abstract: An optical amplifier includes at least one pump source and an optical fiber cable which includes an amplifying optical fiber and a pump optical fiber that are defined by respective lengths. The amplifying optical fiber and the pump optical fiber are coated with a common coating along a portion of their respective lengths, and the fibers are in optical contact with each other along a coating length within the common coating. The common coating has a refractive index which is lower than a refractive index of a cladding material of the pump optical fiber. The fibers are made substantially from glass. The amplifying optical fiber includes a core and a cladding, and is doped with a rare earth dopant. The pump optical fiber is defined by a first end and a second end, the first end of the pump optical fiber being connected to the pump source.

Abstract: An optical amplifier includes at least one pump source and an optical fibre cable which includes an amplifying optical fibre and a pump optical fibre that are defined by respective lengths. The amplifying optical fibre and the pump optical fibre are coated with a common coating along a portion of their respective lengths, and the fibres are in optical contact with each other along a coating length within the common coating. The common coating has a refractive index which is lower than a refractive index of a cladding material of the pump optical fibre. The fibres are made substantially from glass. The amplifying optical fibre includes a core and a cladding, and is doped with a rare earth dopant. The pump optical fibre is defined by a first end and a second end, the first end of the pump optical fibre being connected to the pump source.

Abstract: An optical fiber arrangement has at least two optical fiber sections, each optical fiber section defining an outside longitudinally extending surface. The outside longitudinally extending surfaces are in optical contact with each other. The invention further provides for an amplifying optical device have an optical fiber arrangement as just described, and a pump source. The amplifying optical device is configured such that the pump source illuminates the amplifying optical fiber. A amplifying arrangement is also disclosed. The amplifying arrangement includes a plurality of amplifying optical devices as just described, and each amplifier also has at least one input fiber and a first multiplexer connected to the input fiber. Each amplifier is configured such that at least one of the amplifying optical fibers is connected to the first multiplexer. The amplifying arrangement also has a second multiplexer connected to each of the first multiplexers.

Abstract: A method of producing a planar substrate having waveguide channels, which method comprises: (i) providing a tube (6) of a substrate material; (ii) depositing silica layers (110) on the inside of the tube (6), the silica layers (110) being doped with a photosensitive material; (iii) drawing the tube (6) so that the cross-sectional size of the tube (109) is reduced; (iv) before or after the reducing of the cross-sectional size of the tube (6), causing the tube (6) to collapse into a flat shape by applying a low pressure to the tube, whereby the deposited silica layers together form a photosensitive silica layer (111); (v) cutting to required lengths the tube (6) which has been collapsed and reduced in cross-sectional size; and (vi) using laser writing to define waveguide channels in the cut lengths of the tube (6) and thereby to produce the planar substrate having the waveguide channels.

Abstract: In one embodiment, a photo-darkening resistant optical fibre includes a waveguide having a numerical aperture less than 0.15. The waveguide includes a core having a refractive index n1 and a pedestal having a refractive index n2, and wherein the fibre includes a first cladding having a refractive index n3 surrounding the pedestal, wherein n1 is greater than n2, n2 is greater than n3. The core includes silica, a concentration of alumina of between approximately 0.3 to 0.8 mole percent, a concentration of phosphate of substantially 15 mole percent, a concentration of ytterbium substantially in the range 20000 to 45000 ppm. The pedestal can include silica, phosphate and germania. The core can have substantially zero thulium dopant.

Abstract: In one embodiment, a photo-darkening resistant optical fibre includes a waveguide having a numerical aperture less than 0.15. The waveguide includes a core having a refractive index n1 and a pedestal having a refractive index n2, and wherein the fibre includes a first cladding having a refractive index n3 surrounding the pedestal, wherein n1 is greater than n2, n2 is greater than n3. The core includes silica, a concentration of alumina of between approximately 0.3 to 0.8 mole percent, a concentration of phosphate of substantially 15 mole percent, a concentration of ytterbium substantially in the range 20000 to 45000 ppm. The pedestal can include silica, phosphate and germania. The core can have substantially zero thulium dopant.

Abstract: In one embodiment, a photo-darkening resistant optical fiber includes a waveguide having a numerical aperture less than 0.15. The waveguide includes a core having a refractive index n1 and a pedestal having a refractive index n2, and wherein the fiber includes a first cladding having a refractive index n3 surrounding the pedestal, wherein n1 is greater than n2, n2 is greater than n3. The core includes silica, a concentration of alumina of between approximately 0.3 to 0.8 mole percent, a concentration of phosphate of substantially 15 mole percent, a concentration of ytterbium substantially in the range 20000 to 45000 ppm. The pedestal can include silica, phosphate and germania. The core can have substantially zero thulium dopant.

Abstract: A method of producing a planar substrate having waveguide channels, which method comprises: (i) providing a tube (6) of a substrate material; (ii) depositing silica layers (110) on the inside of the tube (6), the silica layers (110) being doped with a photosensitive material; (iii) drawing the tube (6) so that the cross-sectional size of the tube (109) is reduced; (iv) before or after the reducing of the cross-sectional size of the tube (6), causing the tube (6) to collapse into a flat shape by applying a low pressure to the tube, whereby the deposited silica layers together form a photosensitive silica layer (111); (v) cutting to required lengths the tube (6) which has been collapsed and reduced in cross-sectional size; and (vi) using laser writing to define waveguide channels in the cut lengths of the tube (6) and thereby to produce the planar substrate having the waveguide channels.

Abstract: An optical fibre arrangement has at least two optical fibre sections, each optical fibre section defining an outside longitudinally extending surface. The outside longitudinally extending surfaces are in optical contact with each other. The invention further provides for an amplifying optical device have an optical fibre arrangement as just described, and a pump source. The amplifying optical device is configured such that the pump source illuminates the amplifying optical fibre. A amplifying arrangement is also disclosed. The amplifying arrangement includes a plurality of amplifying optical devices as just described, and each amplifier also has at least one input fibre and a first multiplexer connected to the input fibre. Each amplifier is configured such that at least one of the amplifying optical fibres is connected to the first multiplexer. The amplifying arrangement also has a second multiplexer connected to each of the first multiplexers.

Abstract: An optical fiber arrangement has at least two optical fiber sections, each optical fiber section defining an outside longitudinally extending surface. The outside longitudinally extending surfaces are in optical contact with each other. The invention further provides for an amplifying optical device have an optical fiber arrangement as just described, and a pump source. The amplifying optical device is configured such that the pump source illuminates the amplifying optical fiber. A amplifying arrangement is also disclosed. The amplifying arrangement includes a plurality of amplifying optical devices as just described, and each amplifier also has at least one input fiber and a first multiplexer connected to the input fiber. Each amplifier is configured such that at least one of the amplifying optical fibers is connected to the first multiplexer. The amplifying arrangement also has a second multiplexer connected to each of the first multiplexers.