Editorial

Citation

Loughlin, C. (1998), "Editorial", Sensor Review, Vol. 18 No. 1. https://doi.org/10.1108/sr.1998.08718aaa.001

Editorial

I can remember that when fibre optics first started to be used for data communication, one of the main selling points was that it was very secure ­ no one could intercept your messages without chopping the cable and it would be easy to detect such a violent intrusion. Fibres have since realised much and more of their initial optimistic claims.

New laid submarine cables are now almost exclusively fibre based (as opposed to hefty coax), more channels can be carried and repeaters are now only needed every 100 miles or so. Land based systems are even more prevalent and it will not be long before telephone "wires" are a thing of the past and we are all hooked up to the Net for mega baud communication.

We may break a leg falling into the trench left uncovered by the cable companies, but at least we will be able to carry on our work from the hospital bed.

However, some of the most interesting developments in the world of fibres have come about because of the erroneous claim of our opening premiss.

Fibres are never perfect and if you wrap them around in a coil, sufficient signal will leak out to enable you to monitor the main traffic. Rather a similar effect to that obtained by wrapping a conventional wire around a transformer core. This is bad news if you want secure communications, good news if you want to listen to your neighbour's movie channel for free, and very interesting if you are in the business of developing fibre optic sensors.

The tighter the bend in the fibre the more signal will be lost through the walls, so in its simplest form you can determine the amount of curvature in a fibre by measuring the signal loss. In this issue we have contributions that describe the very many different forms of "defects" or, more kindly, fibre properties that can be exploited to enable us to measure temperature, pressure, electric current and a host of additional measurands.

If the fibres were perfect for their original intended use then many of these sensor properties would not be possible. This theme of exploitation of defects runs through most aspects of sensor technology and illustrates that whether some feature of a device is useful or annoying depends very much on your personal perspective. So next time you are struggling to overcome some interference effect, take solace in the thought that someone can benefit from your difficulty, and that someone may be you.

Clive Loughlin