Stephen W. James

Fibre-Optic Chemical Sensor Approaches Based on Nanoassembled Thin Films: A Challenge to Future Sensor Technology

Optical phenomena have been employed extensively by human civilization throughout the centuries for lighting, communication, calculations, observations, etc. and have played a crucial role in industrial development. The applications of the optics increased significantly after the first demonstration of the light guiding phenomenon based on total internal reflection in the 1840s, which was the precursor for the development of modern optical fibres. In modern life, optical fibres found their niche in telecommunications and, more recently, as sensors.

Optical Fibre Long-Period Gratings Functionalised with Nano-Assembled Thin Films: Approaches to Chemical Sensing

© 2013 Lee et al., licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Optical Fibre Long-Period Gratings Functionalised with Nano-Assembled Thin Films: Approaches to Chemical Sensing

Experimental determination of 2 nd order phase matching turning points in long period gratings

The fabrication of optical fibre long period gratings (LPGs) displaying 2nd order resonant bands operating at the phase matching turning point (PMTP) is explored. Previous reports that exploited 2nd order attenuation bands in sensing schemes did not access the highly sensitive PMTP region. To overcome this limitation, LPGs with periods between 167–177 μm were fabricated using UV irradiation. The spectra acquired were subsequently analyzed and the development of the 2nd order PMTP was identified utilizing peak tracking software. This work has provided the platform for LPG design focused on the prospect of sensitive multi-parameter discrimination.

3D Fibre Optic Laser Doppler Velocimeter

In this paper the design and preliminary testing of a single headed 3D fibre optic laser Doppler velocimeter for implementation on turbomachinery rigs is described.