Abstract
In this work, fabrication and demonstration of a strain sensitive long-period grating (LPG) sensor is discussed. Equally spaced inscription LPG has been fabricated in germanium doped silica (Ge-SiO2) single-mode optical fibre. In the fabrication process amplitude mask approach was employed and KrF excimer laser with 248 nm wavelength has been used for inducing index modulation in the core of fibre. On a single mode fibre, uniform LPG of period 95 mu m and 30 mm grating length has been inscribed and subsequently was used as a strain sensor to monitor the strain up to 7000 mu epsilon. Sensitivity of this sensor is found to be 0.931 nm/1000 mu epsilon whereas for standard fibre Bragg grating, it is 1.2 nm/1000 mu epsilon.