Improved long period fibre gratings sensing devices coated with thin films

Abstract

Long period fibre gratings (LPFG) have found an increasing interest due to the easy fabrication in any kind of fibre through the induced electric arc technique with low cost and flexibility. They have been used in applications such as gainflattening and band-rejection, and for sensing strain, temperature and chemical and biological parameters. The sensitivity of LPFG increases when the fibre is coated with certain thin films. In this short review it is presented the recent developments and applications of these kind of sensors.