Recent developments in optical-fiber-based extrinsic Fabry-Perot interferometric strain sensing technology

Abstract

Progress in the performance and reliability of the fiber-optic-based extrinsic Fabry-Perot interferometric (EFPI) strain sensor is reported. The developments include refined fabrication techniques and improved quality of constituent elements for enhanced durability and greater temperature sustenance, higher strain sensitivity using using high-finesse cavities, a modified sensor-head for complete strain-field characterization, absolute, real-time and inexpensive measurements employing white light interferometry and multipoint, distributed sensing using CDMA and path matching multiplexing techniques. It is shown that these improvements have assisted in overcoming the limitations of the conventional EFPI sensor and made possible the large-scale commercialization of the state-of-the-art EFPI-based strain sensing system.