Design and development of long period gratings sensors for temperature monitoring

Abstract. Long Period Gratings (LPGs) have been developed using carbon diox-ide laser in a standard optical fibre. LPGs with a periodicity of 600 μm and grating length of 24 mm have been inscribed on standard single mode fibre. Such gratings have been used in designing temperature sensors and temperature is monitored up to 80◦C. The sensitivity of such type of sensor is 0·06 nm/◦C where as for standard Fibre Bragg Grating (FBG) it is 0·011 nm/◦C. The LPG performance is also eval-uated after γ-ray irradiation for total dose of 5 KGy and has not shown any effect on transmission spectrum