Recent advancements in cloud computing technologies in the context of optical and optical fibre based systems are
reported. The proliferation of real time and multi-channel based sensor systems represents significant growth in data
volume. This coupled with a growing need for security presents many challenges and presents a huge opportunity for an
evolutionary step in the widespread application of these sensing technologies. A tiered infrastructural system approach is
adopted that is designed to facilitate the delivery of Optical Fibre-based “SENsing as a Service- SENaaS". Within this
infrastructure, novel optical sensing platforms, deployed within different environments, are interfaced with a Cloud-based
backbone infrastructure which facilitates the secure collection, storage and analysis of real-time data. Feedback systems,
which harness this data to affect a change within the monitored location/environment/condition, are also discussed. The
cloud based system presented here can also be used with chemical and physical sensors that require real-time data analysis,
processing and feedback.
In this paper, two optical fibre sensors are presented: 1) based on extrinsic Fabry-Perot Interferometer (EFPI) with Fibre Bragg Grating array and 2) and EFPI sensor with a chirped Fibre Bragg grating (CFBG). The CFBG with EFPI sensor fabrication technique is described and temperature response of both sensors is presented. Such sensors have many potential applications including applications in the aerospace industry and medical industry (e.g. radio frequency thermal ablation of tumors).
A fibre optic extrinsic Fabry Perot Interferometer (EFPI) sensor is developed for monitoring pressure in the underwater and sub-seabed under simulated conditions. The sensor is robust in design and is fabricated entirely from Silica glass. The EFPI is formed at the tip of the fibre, where the single mode is spliced to a 200μm capillary, sealed by a 200μm Multimode, which forms the diaphragm. The diaphragm thickness is reduced by polishing and etching with hydrofluoric (HF) acid to about 2-3μm for a high sensitivity. The thickness of the diaphragm is monitored online during polishing and HF etching. The spectrum of the fibre optic sensor (FOS) is interrogated using a broad band optical light source and an optical spectrometer. The sensitivity of the sensor achieved is 0.6cmH2O, excellent for small depth-changes. Experimental measurements with saturated salt water and chlorophyll pigmentation of different standards were tested, to simulate the sub-sea conditions where a stability of 0.7cmH2O was reached with a drift of less than 10% under the simulated conditions.
In order to satisfy increasingly stringent maritime pollution control laws, it is necessary to develop sensors that are
capable of quantifying exactly the pollutants entering the marine environment. The development of an optical fibre based
sensor array suitable for the detection of known pollutants is discussed in this paper. The system being presented will
demonstrate how the incorporation of a novel fibre optic based sensor, with the ability to detect minute changes of
impurity in a liquid can be used on a Mote based platform in a real-time monitoring scenario and all for a relatively low
cost. [1]
A novel fibre-cavity design based on highly reflective gold coatings, vapor-deposited to the two end faces of a
400um multimode waveguide, is presented. In contrast to common fibre-cavity approaches, the laser pulses are
not coupled through the reflective coatings into the cavity but through a micro hole in one of the fibre end
faces, which reduces the coupling losses from generally almost 100! to less than 1!. Since the decay function
of the back and forth reflected pulses is acquired through the same micro hole, a compact bi-directional module
can be used for pulse transmission and acquisition, consisting of a low power uncooled laser source and a fast
photodiode detector. By choosing the cavity length to be longer than the pulse width, wavelength tuning of the
pulses can be omitted resulting in a simplified hardware setup. Thus, the novel fibre-cavity design facilitates
ring-down experiments and considerably reduces the cost of the associated sensor applications.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.