Fibre optics waveguides

The key innovations in turning optical waveguides (fibres) into a successful commercial product were made by R.D. Maurer in the research laboratories of the Corning Glass Company in New York State. This company was also responsible for introducing another family of products, crystalline ceramics made from glass precursors - glass-ceramics. The story of this development carries many lessons for... 

Boisde G., Harmer A., Chemical and biochemical sensing with optical fibres and waveguides, Boston - London Artech House, 1996. 

Optical sensors (Figure 1) can be defined as devices for optical monitoring of physical parameters (pressure1, temperature2, etc.) or (bio)chemical properties of a medium by means of optical elements (planar optical waveguides or optical fibres). Chemical or biochemical fibre-optic sensors3 are small devices capable of continuously and reversibly recording the concentration of a (bio)chemical species constructed be means of optical fibres. 

Polymer materials are frequently used matrices for the indicator chemistry in optical sensors. This is necessary for several reasons first, the indicator has to be immobilized to an optical waveguide or an optical fibre which is then brought into contact with the analyte solution. If one would pour an aqueous solution of the indicator dye directly into the sample solution, e.g. into a bioreactor, then the whole sample solution would be contaminated. 

Fibre optic-based flow-through optical biosensors The dramatic advances in fibre optic development in die last decade have promoted construction of sensors where radiation, whether emitted, transmitted or reflected, is conducted fi-om the sample to the detection system. The wide variety of available optical waveguide types (solid rods, hollow cylinders, micro-planar geometries) has been used with varying success in sensor development. 

Boisde, G. Harmer, A. Chemical and Biochemical Sensing with Optical fibres and waveguides, Artech House Boston, MA, 1996... 

Fig. 3. Composite loss spectra for some common IR fibre optics ZBLAN fluoride glass SC sapphire, chalcogenide glass, PC AgBrCl, and hollow glass waveguide plot reproduced from Harrington, 2010.

An alternative approach to remote mid infra-red spectroscopy is presented which utilises gold-coated waveguides instead of fibre optics and which could be used for in-situ real-time process control in practically any environment. The principle objects of the paper are to describe a novel experimental set-up for remote mid infra-red spectroscopy recently assembled in laboratory, and to demonstrate the qualitative and quantitative analysis of the remote mid infra-red data using a multifunctional epoxy/amine formulation as an example. 18 refs. 

At the heart of this application stands an array of electrostatically actuated micromirrors that will be described below. In modern fibre optical telecommunication networks there is an increasing demand for optical switches at hubs that redirect and distribute streams of incoming data by multiplexing into the right optical channels. Another application presented below is the manipulation of optical waveguides by microactuators. 

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