Abstract: A microstructured optical fiber sensor for sensing changes in a physical characteristic up to a predetermined temperature is disclosed. The sensor includes a microstructured optical fiber and a fiber Bragg grating formed in the microstructured optical fiber by generating a periodic modulation in the refractive index along a core region of the suspended core. The fiber Bragg grating is configured to produce a band reflection spectra including a fundamental mode and a plurality of higher order modes whose respective wavelengths vary in accordance with changes in the physical characteristic at the core region of the microstructured optical fiber. The microstructured optical fiber is configured to increase the confinement loss of the plurality of higher order modes of the band reflection spectra relative to the fundamental mode.

Abstract: A method of forming a capillary tube for electrospray ionization (ESI) having at least one tip with a desired tip profile. The method includes providing a pre-finished capillary tube of substantially homogenous material. The capillary tube has a first end and an internal bore. The first end of the pre-finished capillary tube is wet-etched in an etchant for an etch duration. A protective fluid flows through the internal bore of the capillary tube at a flow rate during the etch duration and the flow rate and the etch duration are determined to obtain the desired tip profile below a liquid level of the etchant.

Abstract: A method of forming metallic nanoparticles in glass is disclosed that creates evenly distributed metallic nanoparticles with desired size in any glass type. Formation of a source of electrons trapped on the surface of the glass particles by crushing and grinding glass material into powder followed by heat treatment of the glass powder to neutralise metal ions doped in the glass by the trapped source of electrons, followed by the aggregation and growth of the metal into nanoparticles. The present method allows the homogeneous distribution of metal nanoparticles throughout the glass volume. The size and concentration of the metallic nanoparticles is controlled by the heat treatment temperature and duration as well as the amount of metal ions.

Abstract: A method of forming a capillary tube for electrospray ionization (ESI) having at least one tip with a desired tip profile. The method includes providing a pre-finished capillary tube of substantially homogenous material. The capillary tube has a first end and an internal bore. The first end of the pre-finished capillary tube is wet-etched in an etchant for an etch duration. A protective fluid flows through the internal bore of the capillary tube at a flow rate during the etch duration and the flow rate and the etch duration are determined to obtain the desired tip profile below a liquid level of the etchant.

Abstract: A die and method for extruding an extrudable material to form an extruded member is described. In one embodiment, the die comprises a barrier member comprising a plurality of feed channels that extend through the barrier member. Furthermore, the die incorporates a passage forming member extending from the barrier member substantially in the direction of extrusion. The feed channels are arranged with respect to the passage forming member to allow the extrudable material to substantially flow about the passage forming member to form a corresponding passage in the extruded member.

Abstract: Prior to fabrication of an optical fiber with desired optical properties, a preform geometry is determined dependent upon a fiber geometry that possesses the desired optical properties. The desired geometry may contain a large number of channels. The processor determines the preform geometry by tracking backwards in time the parameters of a set of conformal mappings that describe the cross section of the fiber. Some of the drawing process parameters may be specified, while other parameters may be determined along with the preform geometry. The determined preform geometry may be used to fabricate the required preform. Using this preform, the determined drawing process parameters may be used to draw the desired fiber.

Abstract: A die and method for extruding an extrudable material to form an extruded member is described. In one embodiment, the die comprises a barrier member comprising a plurality of feed channels that extend through the barrier member. Furthermore, the die incorporates a passage forming member extending from the barrier member substantially in the direction of extrusion. The feed channels are arranged with respect to the passage forming member to allow the extrudable material to substantially flow about the passage forming member to form a corresponding passage in the extruded member.

Abstract: Prior to fabrication of an optical fiber with desired optical properties, a preform geometry is determined dependent upon a fiber geometry that possesses the desired optical properties. The desired geometry may contain a large number of channels. The processor determines the preform geometry by tracking backwards in time the parameters of a set of conformal mappings that describe the cross section of the fiber. Some of the drawing process parameters may be specified, while other parameters may be determined along with the preform geometry. The determined preform geometry may be used to fabricate the required preform. Using this preform, the determined drawing process parameters may be used to draw the desired fiber.

Abstract: A sensor based on optical fiber technology is described. The sensor includes an elongate core for propagating light having an excitation wavelength; an interaction region that includes a fluorescent material for excitation by the propagated light to produce fluorescent light; and an interface region defining a boundary between the elongate core and the interaction region. The elongate core of the sensor is adapted to increase an intensity of the propagated light at the interface region to increase the amount of captured fluorescent light in the elongate core.

Abstract: The present disclosure provides an optical detector for detecting radiation. The optical detector includes an optical light guide that incorporates a sensing region. The sensing region includes a sensing material that emits luminescence light when the sensing material is exposed to suitable ionizing radiation and accrues trapped charge which is released and produces optically stimulated luminescence (OSL) when the sensing material is optically stimulated. The optical detector also includes a light source for optically stimulating the sensing material and a light detector for detecting the OSL. The optical light guide is arranged to guide light through the sensing region and between the sensing region and the luminescence light detector.

Abstract: A method of forming a nanowire is disclosed. In one embodiment, a primary preform is formed comprising at least one central region and a support structure. The primary preform is then drawn to a cane, which is then inserted into an outer portion, to form a secondary preform. The secondary preform is then drawn until the at least one central portion is a nanowire. The method can produce nanowires of far greater length than existing methods, and can reduce the likelihood of damaging the nanowire when handling.

Abstract: A method of forming a nanowire is disclosed. In one embodiment, a primary preform is formed comprising at least one central region and a support structure. The primary preform is then drawn to a cane, which is then inserted into an outer portion, to form a secondary preform. The secondary preform is then drawn until the at least one central portion is a nanowire. The method can produce nanowires of far greater length than existing methods, and can reduce the likelihood of damaging the nanowire when handling.

Abstract: A sensor based on optical fiber technology is described. The sensor includes an elongate core for propagating light having an excitation wavelength; an interaction region that includes a fluorescent material for excitation by the propagated light to produce fluorescent light; and an interface region defining a boundary between the elongate core and the interaction region. The elongate core of the sensor is adapted to increase an intensity of the propagated light at the interface region to increase the amount of captured fluorescent light in the elongate core.

Abstract: A die and method for extruding an extrudable material to form an extruded member is described. In one embodiment, the die comprises a barrier member comprising a plurality of feed channels that extend through the barrier member. Furthermore, the die incorporates a passage forming member extending from the barrier member substantially in the direction of extrusion. The feed channels are arranged with respect to the passage forming member to allow the extrudable material to substantially flow about the passage forming member to form a corresponding passage in the extruded member.

Abstract: A method of forming a nanowire is disclosed. In one embodiment, a primary preform is formed comprising at least one central region and a support structure. The primary preform is then drawn to a cane, which is then inserted into an outer portion, to form a secondary preform. The secondary preform is then drawn until the at least one central portion is a nanowire. The method can produce nanowires of far greater length than existing methods, and can reduce the likelihood of damaging the nanowire when handling.