Abstract: A method and apparatus for inscribing a high-temperature stable Bragg grating in an optical waveguide, comprising the steps of: providing the optical waveguide; providing electromagnetic radiation from an ultrashort pulse duration laser, wherein the wavelength of the electromagnetic radiation has a characteristic wavelength in the wavelength range from 150 nanometers (nm) to 2.

Abstract: The present invention provides an efficient quantum memory for storing a quantum state of light, such as a photon, for a temporary period of time in a fibre-integrated optical cavity and then recall the quantum state of light and quantum information at a later time with a high probability of success. The present invention uses a nonlinear optical switching mechanism to modify at least one property of the quantum light, or cavity, to trap the quantum light in the optical cavity. Subsequent application of the nonlinear optical switching mechanism switches at least one property of the stored quantum light, or cavity, to release the quantum light from the optical cavity. The present invention also provides quasi-deterministic single-photon generation by temporal multiplexing of a photon pair source integrated within the cavity.

Abstract: T-phase-shifted fiber Bragg gratings in optical waveguides, and methods of formation thereof. Sensing apparatus comprising such gratings using femtosecond pulse duration lasers and specialized transmission diffraction elements or phase masks.

Abstract: A solution is provided comprising boron nitride nanotubes (BNNTs) in a liquid solvent. An optical waveguide, such as an optical fiber, is contacted with the solution so as to form a layer of the solution supported on at least a portion of the optical waveguide. The liquid solvent is then removed from the layer of the solution supported on the optical waveguide in order to form a coating of the BNNTs on the optical waveguide. Further provided is a BNNT coated optical waveguide for use as a sensor.

Abstract: A method and apparatus for inscribing a Bragg grating in an optical waveguide, comprising: providing electromagnetic radiation from an ultrashort pulse duration laser, wherein the electromagnetic radiation has a pulse duration of less than or equal to 5 picoseconds, and wherein the wavelength of the electromagnetic radiation has a characteristic wavelength in the wavelength range from 150 nanometers (nm) to 2.0 microns (µm); providing cylindrical focusing optics corrected for spherical aberration; providing a diffractive optical element that when exposed to the focused ultrashort laser pulse, creates an interference pattern on the optical waveguide, wherein the irradiation step comprises irradiating a surface of the diffractive optical element with the focused electromagnetic radiation, the electromagnetic radiation incident on the optical waveguide, from the diffractive optical element, being sufficiently intense to cause the permanent change in the index of refraction in the core of the optical waveguide.

Abstract: A solution is provided comprising boron nitride nanotubes (BNNTs) in a liquid solvent. An optical waveguide, such as an optical fiber, is contacted with the solution so as to form a layer of the solution supported on at least a portion of the optical waveguide. The liquid solvent is then removed from the layer of the solution supported on the optical waveguide in order to form a coating of the BNNTs on the optical waveguide. Further provided is a BNNT coated optical waveguide for use as a sensor.

Abstract: An apparatus, method and system are set forth for detection of fluids using Bragg grating sensors, wherein the Bragg grating sensing element comprises an optical fiber having a Bragg grating inscribed therein characterized by optical properties that are dependent upon the periodicity and effective refractive index of the grating, and a package for subjecting the Bragg grating to a change in strain when contacted by a fluid such that periodicity and effective refractive index of the grating changes, whereby when interrogated with laser light any such change in periodicity and effective refractive index may be detected.

Abstract: Provided is an optical waveguide with an inscribed Bragg grating, where the Bragg grating is stable at high temperature, has low scattering loss and high reflectivity. Also provided is a method for inscribing a Bragg grating in an optical waveguide, the method comprising irradiating the optical waveguide with electromagnetic radiation from an ultrashort pulse duration laser of sufficient intensity to cause a permanent change in an index of refraction within a core of the optical waveguide, where the irradiating step is terminated prior to erasure of a Bragg resonance, and heating the optical waveguide to a temperature and for a duration sufficient to substantially remove a non-permanent grating formed in the optical waveguide by the irradiating step.

Abstract: T-phase-shifted fiber Bragg gratings in optical waveguides, and methods of formation thereof. Sensing apparatus comprising such gratings using femtosecond pulse duration lasers and specialized transmission diffraction elements or phase masks.

Abstract: Provided is an optical waveguide with an inscribed Bragg grating, where the Bragg grating is stable at high temperature, has low scattering loss and high reflectivity. Also provided is a method for inscribing a Bragg grating in an optical waveguide, the method comprising irradiating the optical waveguide with electromagnetic radiation from an ultrashort pulse duration laser of sufficient intensity to cause a permanent change in an index of refraction within a core of the optical waveguide, where the irradiating step is terminated prior to erasure of a Bragg resonance, and heating the optical waveguide to a temperature and for a duration sufficient to substantially remove a non-permanent grating formed in the optical waveguide by the irradiating step.

Abstract: Provided is an optical waveguide with an inscribed Bragg grating, where the Bragg grating is stable at high temperature, has low scattering loss and high reflectivity. Also provided is a method for inscribing a Bragg grating in an optical waveguide, the method comprising irradiating the optical waveguide with electromagnetic radiation from an ultrashort pulse duration laser of sufficient intensity to cause a permanent change in an index of refraction within a core of the optical waveguide, where the irradiating step is terminated prior to erasure of a Bragg resonance, and heating the optical waveguide to a temperature and for a duration sufficient to substantially remove a non-permanent grating formed in the optical waveguide by the irradiating step.

Abstract: There is provided an alignment system and method for use in an ultrashort pulse duration laser-based Fiber Bragg Grating (FBG) writing system, the alignment system comprising: clamps configured to hold a coated optical fiber in a position perpendicular to a beam path of an ultrashort pulse duration laser-based FBG writing station; an optical detector; and a control system with an input from the optical detector and an output to adjust parameters of an optical source and the FBG writing station adjust a distance between the optical fiber and an optical source of the writing station based on luminescence generated in a core of the optical fiber as indicated in a signal received at the input from the optical detector.

Abstract: Provided is an optical waveguide with an inscribed Bragg grating, where the Bragg grating is stable at high temperature, has low scattering loss and high reflectivity. Also provided is a method for inscribing a Bragg grating in an optical waveguide, the method comprising irradiating the optical waveguide with electromagnetic radiation from an ultrashort pulse duration laser of sufficient intensity to cause a permanent change in an index of refraction within a core of the optical waveguide, where the irradiating step is terminated prior to erasure of a Bragg resonance, and heating the optical waveguide to a temperature and for a duration sufficient to substantially remove a non-permanent grating formed in the optical waveguide by the irradiating step.

Abstract: There is provided an alignment system and method for use in an ultrashort pulse duration laser-based Fiber Bragg Grating (FBG) writing system, the alignment system comprising: clamps configured to hold a coated optical fiber in a position perpendicular to a beam path of an ultrashort pulse duration laser-based FBG writing station; an optical detector; and a control system with an input from the optical detector and an output to adjust parameters of an optical source and the FBG writing station adjust a distance between the optical fiber and an optical source of the writing station based on luminescence generated in a core of the optical fiber as indicated in a signal received at the input from the optical detector.

Abstract: A device for providing an expanded mode field from a single mode optical waveguide is formed by fusing a length of single mode optical fiber with a length of fiber rod absent a cladding and adiabatically tapering the fused region. The length of single mode fiber has a core having a refractive index nco and a cladding having a refractive index ncl, wherein ncl<nco and wherein the cladding has an outer diameter ?. The length of fiber rod absent the cladding has a refractive index of the fiber rod is substantially the same as the cladding index ncl of the single mode optical fiber. The outer diameter of the length of fiber rod is ?, the same as the cladding diameter of the single mode fiber.

Abstract: A device for providing an expanded mode field from a single mode optical waveguide is formed by fusing a length of single mode optical fiber with a length of fiber rod absent a cladding and adiabatically tapering the fused region. The length of single mode fiber has a core having a refractive index nco and a cladding having a refractive index ncl, wherein ncl<nco and wherein the cladding has an outer diameter ?. The length of fiber rod absent the cladding has a refractive index of the fiber rod is substantially the same as the cladding index ncl of the single mode optical fiber. The outer diameter of the length of fiber rod is ?, the same as the cladding diameter of the single mode fiber.

Abstract: A method of increasing the refractive index in a photosensitive glass is disclosed so as to induce an refractive index change of at least 10?5 within a region of the glass. The method includes the step of providing a hydrogen or deuterium loaded doped glass material wherein a dopant within the glass is photosensitive to infrared radiation in the presence of hydrogen or deuterium. The hydrogen or deuterium loaded doped glass is subsequently irradiated with femtosecond pulses of infrared light having an intensity of at least 109 W/cm2 and less than 5×1013 W/cm2.

Abstract: The invention relates to an optical waveguide device for monitoring a characteristics of light, e.g. a wavelength. The device incorporates a waveguide, such as an optical fiber, with an embedded tilted Bragg grating operating in a regime of wavelength detuning. The grating is designed to disperse light azimuthally in two or more different directions about the fiber axis, said directions changing with wavelength. A photodetector array is provided for detecting the azimuthal distribution of light. A processor coupled to the photodetector array determines wavelength information from the detected azimuthal distribution of the out-coupled light.

Abstract: A retro-reflective sensor for sensing mechanical, chemical or temperature related information, is disclosed. The sensor is formed of an optical waveguide suitable for use in-situ in a high temperature environment having a Bragg grating written into a core region thereof with short-pulsed electromagnetic radiation, said optical waveguide having a glass transition temperature substantially higher than that of silica. Preferably the sensor is written into a length of sapphire fiber or within a zirconium waveguide. Preferably the pulse duration of the short pulsed electromagnetic radiation is less than 500 picoseconds.

Abstract: A retro-reflective sensor for sensing mechanical, chemical or temperature related information, is disclosed. The sensor is formed of an optical waveguide suitable for use in-situ in a high temperature environment having a Bragg grating written into a core region thereof with short-pulsed electromagnetic radiation, said optical waveguide having a glass transition temperature substantially higher than that of silica. Preferably the sensor is written into a length of sapphire fiber or within a zirconium waveguide. Preferably the pulse duration of the short pulsed electromagnetic radiation is less than 500 picoseconds.