Fibre-optic sensor

OT1442 A fibre optic sensor for flexible pipeline and riser integrity momtonng... 

An integral part of a fibre optic sensor is the light source. Its primary task is to deliver an appropriate light, which possesses such features as an optical power suitable to interact with an analyte or an indicator from the optrode, a wavelength matched to the spectral properties of the sensors in order to obtain the highest sensitivity, and, in dependence on the construction of the sensor, polarisation, short pulse etc. There are many various light sources utilised in the fibre optic chemical sensors. They differ in spectral properties, generated optical power and coherence. 

Figure 1. Principal arrangement of fibre-optic sensors.

So the function of special optical fibres for sensing is to produce a sensitive response to changes in the fibre surroundings. Such requirements on optical hardware as durability to the analyte, transparency (i.e. minimum optical losses) in a wide spectral range and common availability should be pointed out. Related to the these requirements, the choice of the fibre material as well as of the fibre coating and fibre structure belong to fundamental tasks in the design of fibre-optic sensors. 

K.T.V. Grattan, Fibre optic sensor technology, Sensors Actuators A 2000 82 40-61. 

Klainer S.M., Thomas J.R., Francis J.C., Fibre-optical, sensors offer a realistic solution to environmental monitoring needs, Sensors Actuators B 1993 11 81-86. 

The continuous determination of compounds, which may adversely affect ecosystems and/or human health, is a major regulative and legislative goal of environmental protection nowadays. Considering the costs and efforts related to this task corroborates a clear demand for portable, real-time, in-situ, field applicable and cost-effective monitoring techniques. Due to their inherent properties, vibrational spectroscopic sensors, in particular fibre-optic sensors show a high potential to contribute to these applications. 

Gautier S.M., Blum L.J., Coulet P.R., Multifunction fibre-optic sensor for the selected bioluminescent flow determination of ATP or NADH, Anal. Chim. Acta 1990 235 243-253. 

Yan H.M., Kraus G., Gauglitz G., Detection of Mixtures of Organic Pollutants in Water by Polymer Film Receptors in Fibre-Optical Sensors Based on the Reflectometric Interference Spectrometry, Anal ChimActa 1995 312 1-8. 

James, S. W. Tatarn, R. P., Fibre optic sensors with nano structured coatings, J. Opt. A 2006, 8, S430 S444... 

S. M. Gautier, I. J. Blum, andP. R. Coulet, Bioluminescence-based fibre optic sensor with entrapped co-reactant An approach for designing a self-contained biosensor, Anal. Chim. Acta 243, 149-156 (1991). 

C. Schelp, T. Scheper, F. Buckmann, and K. F. Reardon, Two fibre-optic sensors with confined enzymes and coenzymes Development and applications, Anal Chim Acta 255, 223-229 (1991). 

E. Saaski, A family of fibre optic sensors using cavity resonator microshifts, Proc. of 4th Intern. 

A. L. Harmer, Fibre optic sensors for offshore process control instrumentation, Proc. Optical Fibre Sensors Conference (OFS 86), Informal Workshop at Tusukuba Science City, 1986, VII. Pub Institute of Electronics and Communication Engineers of Japan, Tokyo, 1986. 

C. Dahne, R. M. Sutherland, J. F. Place, and A. S. Ringrose, Detection of anti body-antigen reactions at a glass-liquid interface A novel fibre-optic sensor concept, Corf. Proc. OFS 84, 2nd International Conference on Optical Fiber Sensors, pp. 75-79 (1984). 

Figure 3.6 — (A) Fibre-optic biosensor system a septum b needle guide c thermostated reaction vessel d fibre bundle e enzyme membrane f screw cap g stirring bar h reaction medium i black PVC jacket j 0-ring. (B) Continuous-flow fibre-optic sensor system for the bioluminescence determination of NADH. (Reproduced from [41] with permission of Marcel Dekker, Inc.)...

Figure 4 Different partition of sensitive elements from fibre optical sensors.

Fibre-optic sensors, a passive smart textile... 

Optical sensors display several advantages over electronic sensors. Since photons rather than electrons carry the information, they are almost immune to electrical interference. Usually the optical components are made from glass chips or fibre-optic cable fibres, giving them excellent mechanical and thermal stability and often, moreover, a high chemical resistivity. Finally the use of glass, especially fibre-optic, fibres helps to minimise the size and weight of these sensors. Optical sensors, especially fibre-optic sensors have been the subject of several recent reviews [116-120]. 

The detonation velocity is the rate of propagation of a detonation in an explosive if the density of the explosive is at its maximum value, and if the explosive is charged into columns which are considerably wider than the critical diameter, the detonation velocity is a characteristic of each individual explosive and is not influenced by external factors. It decreases with decreasing density of packing in the column. It is measured by ionisation probes or fibre optical sensors. 

Fig. 20.6. Template examined using fibre optic sensor.

Tromberg BJ, Sepaniak MJ, Alarie JP, et al. 1988. Development of antibody-based fibre-optic sensors for detection of a benzo(a)pyrene metabolite. Anal Chem 60(18) 1901-1908. 

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