SMART SENSING AND IMPROVED SENSITIVITY OF FIBER GRATINGS TO TEMPERATURE AND STRAIN

The response mechanism of fiber gratings to temperature and strain is analyzed. After reviewing various fiber core materials, fabrication techniques and coating methods, we discuss the basic methods of improving the sensitivity of fiber gratings to temperature and strain. These include hybrid FBG/LPFG sensing, the use of temperature-sensitive and strain-sensitive fiber core materials, direct fabrication by ultrashort pulsed lasers and polymer overlay coating.