Fibre optic sensors

Fibre optic sensors are being developed which have significant potential for sensing a variety of physical variables. These include acoustic pressures, magnetic fields, temperature, acceleration and rate of rotation. This paper concentrates mainly on acoustic sensors which use fibre optic interferometers sensitive to acoustic fields. The influence of various noise sources on the detection processes is described. Techniques for varying the acoustic and magnetic sensitivity of optical fibres are discussed and some advantages associated with the geometric versatility of their sensors considered. Several non-interferometric acoustic sensors which are amplitude sensitive to acoustic fields are discussed. Finally a brief account of fibre optic magnetic sensors and accelerometers is given.