This thesis investigates properties and applications of Holey Fibre (HF), a recent innovation in the field of optical waveguiding. HF is an all-silica optical fibre with a solid core surrounded by an array of air holes that provide a low-index cladding. The strong guidance of HF and the numerous degrees of freedom available in design give rise to novel properties, including the capability of si...

In this paper, we present the development and testing of an optical-based sensor for monitoring the corrosion of reinforcement rebar. The testing was carried out using an 80% etched-cladding Fibre Bragg grating sensor to monitor the production of corrosion waste in a localized region of the rebar. Progression of corrosion can be sensed by observing the reflected wavelength shift of the FBG sens...

In this paper we introduce a new mathematical model, which can be used to investigate the response of a long-period fibre grating to changes in ambient refractive indices of values both greater and less than that of the cladding. A numerical method to calculate the HE core and cladding modes is presented. The results show that even when the ambient refractive index is higher than that of the cl...

An optical fibre chemical sensor that is insensitive to interfering parameters including temperature and surrounding refractive index is described. The sensor is based upon a Mach-Zehnder interferometer formed by a pair of identical cascaded long period gratings (LPGs), with the entire device coated with a mesoporous coating of silica nanoparticles. A functional material is infused only into th...

An optical fibre long period grating (LPG) sensor modified with molecularly imprinted polymer nanoparticles (nanoMIPs) for the specific detection of antibiotics is presented. The operation of the sensor is based on the measurement of changes in refractive index induced by the interaction of nanoMIPs deposited onto the cladding of the LPG with free vancomycin (VA). The binding of nanoMIPs to van...

Characteristics of cladding modes in a photonic crystal fiber (PCF) are numerically analyzed using the plane wave expansion method. The presence of the outer silica ring in the PCF tends to push the optical fields of the cladding modes toward the rim of the PCF, which creates 'ring modes' whose fields are tightly confined in the outer ring. The dispersion of the cladding modes are determined ma...

Enzyme-functionalized dual-peak long-period fiber grating (LPFG) inscribed in 80 - ? m -cladding B/Ge codoped single-mode fiber is presented for sugar-level and specific glucose detection. Before enzyme functionalization, the dual-peak LPFG was employed for refractive index sensing and sugar-level detection and high sensitivities of ? 4298.20 ?? nm / RIU and 4.6696 ?? nm / % were obtained, resp...

The phenomenon of destruction of silica fiber cladding by the fiber fuse effect has been observed for the first time to the authors' knowledge. Experiments on the optical discharge propagation along a fiber were conducted with fibers of decreased cladding thickness. The destruction of fiber cladding led to expansion of the optical discharge plasma and to a decrease of its density. This resulted...

This chapter gives a theoretical picturization of the evanescent field at the core-cladding interface of dielectric waveguides and deals with the theoretical modelling ofevanescent wave based fibre optic sensors. We also discuss some crucial parameters which are very much essential in the design of a variety of intensity modulated evanescent wave fibre optic sensors.