Aos Products

Dual Cavity Displacement Sensor

As part of a previous development programme AOS Technology Ltd have developed a novel dual-cavity optical displacement sensor for confined area access.  Based upon two Fabry-Perot measurement cavities, each of differing length, the sensor button arrangement uses a precision

fibre alignment process in order to turn the optical transmission path through 90 degrees.

The nominal difference in the sensing cavity lengths is produced by manufacturing the sensor in two halves.  Each half is aligned separately and the fibre end faces polished before the two subcomponents are joined.

A series of optical coating ensures that there is minimal insertion loss to the sensor signals in both the forward and reverse directions.

The dual cavity sensor has a major diameter of only 8mm and is 2mm thick. Sensor can be manufactured from either large-core multimode, standard communications grade multimode or singlemode optical fibre.

The buttons themselves are manufactured from stainless steel although other materials can be used. Due to its robust construction this sensor is capable of measuring position information under high g-loading.

The sensors can be interrogated in a number of different ways depending upon the measurement surface under investigation and the magnitude of the reflected/scattered signal.

Typically scanning laser technologies are utilised in order to ensure measurement accuracy and a reasonable signal-to-noise ratio. Alternative low coherence or simple amplitude measurements may also be suitably implemented. 

These sensors were manufactured from polyimide coated optical fibre. Although possible to manufacture from acrylate coated optical fibre the sensor is less robust and has a lower temperature rating.

For further information please contact us here



         AOS Technology Ltd, 14 Pate Road, Melton Mowbray, Leicestershire, LE13 0RG, UK    T: 01664 567711