Recent advances in the fiber extrinsic Fabry-Perot interferometric strain sensor development

Fiber sensors have found numerous industrial, military and civil applications in the early 1990s. These sensors possess small size and high sensitivity, are immune to electromagnetic interference and can be easily modified for distributed or multi-parameter measurement. The extrinsic Fabry-Perot interferometric (EFPI) fiber optic sensor, although retaining all these advantages, still has a few limitations which have prevented its large scale commercialization as an effective strain gauge. We discuss these limitations and report the development of techniques which have allowed these shortcomings to be surmounted, in terms of both the sensor fabrication and the sensor operation