The Hong Kong Polytechnic University

Dongning Wang

Minwei Yang

Wei Jin

Ying Wang

Jian Lu

Yiping Wang

Changrui Liao

Xiaohui Fang

Xia Fang

Yuhua Li

A method of fabricating Fiber Bragg gratings in a micro/nanofiber using ultrashort pulse irradiation, the method includes elongating and flame-brushing a single mode optical fiber to create a micro/nanofiber, and generating the ultrashort pulse irradiation to induce a plurality of refractive index changes at predetermined intervals within the micro/nanofiber, wherein the ultrashort pulse propagates through a focusing element and a diffractive element prior to propagating on the micro/nanofiber.

Fiber bragg grating in micro/nanofiber and method of producing the same

A fiber-inline MZI device for temperature sensing or refractive index (RI) sensing, the device comprising: a section of a Photonic Crystal Fiber (PCF) having at least two air holes infiltrated with a liquid analyte to form a waveguide channel, the liquid analyte forming rods in the PCF; wherein the rods leave an interference fringe pattern in the transmission spectrum when light is injected into the PCF, and fringe dips are tracked over a wide wavelength range in order to sense the temperature or refractive index.

Fiber in-line Mach-Zehnder interferometer (MZI) device

A single fiber Mach-Zehnder interferometer comprises an optical fiber having a core region and a cladding surrounding the core region, and a micro-cavity having part of the cladding and the core region removed, wherein the micro-cavity is adapted to receive a light beam and separate the light beam into a first light beam that propagates through the micro-cavity in an unguided mode, and a second light beam that propagates through the core region in a guided mode.

In-line single fiber Mach-Zehnder interferometer

An optical fiber with long period fiber gratings includes an optical fiber axis, a core region extending along the fiber axis, the core region having a core refractive index, a cladding region surrounding the core region, the cladding having a cladding refractive index, and a plurality of microholes perpendicular to the fiber axis with a portion of the core region removed, the plurality of microholes are spaced apart by a grating period.

Microhole-structured long period fiber grating

An optical fiberwith a high thermal resistance fiber Bragg grating (FBG). Compared to existing FBG's, the invention provides greatly enhanced thermal stability, being stable up to 1200&#xb0; C. The grating reflectivity and resonant wavelength are maintained for extended duration at high temperatures. The FBG is thus suitable in high temperature sensors. The high thermal resistance of the FBG is obtained in a method of pre-annealing the optical fiberat high temperature prior to inscribing the FBG. The high thermal resistance is optionally enhanced in a post-FBG creation step of heat treating the optical fiberand FBG.

High temperature sustainable fiber bragg gratings

In the present invention, methods and systems for fabricating novel LPFGs are taught. Fabrication is preformed by focusing a COlaser beam having a diameter of 30 to 40 &#x3bc;m onto a fiber, such fiber being fixed and weighted on either ends. The variations of transmission spectrum and polarization dependent (PDL) loss of the COlaser-grooved LPFGs with different fabrication parameters as functions of applied as functions of applied tensile stain are demonstrated and evaluated.

[object Object]

An optical pulses emitter includes a first and a second Fabry-Perot laser diodes. The first and second laser diodes have a first and second working optical wavelength band respectively, and the first and second working wavelength bands has at least an overlapped wavelength band. The emitter also includes a signal source in connection with the first laser diode such that a plurality of optical pulses over the first working optical wavelength band is generated and an optical filter for filtering the optical pulses so as to output a plurality of optical pulses primarily of a desired optical wavelength, which falls into the overlapped wavelength band. The emitter further includes an optical amplifier along an optical path between the first and second Fabry-Perot laser diodes for amplifying the optical signals passing therethrough. The optical pulses primarily of the desired optical wavelength are injected into the second laser diode, and the second laser diode, stimulated by the injected optical signals, outputs optical pulses primarily of the desired optical wavelength.

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Hong Kong, China

Dongning Wang