Effect of material and waveguide parameters on strain sensitivity of uniform long-period fiber grating

This study validates the dependency of strain sensitivity of uniform long period fiber grating (LPFG) on its periodic structure and mode order. Due to applied axial strain the material and waveguide parameters of LPFG changes which cause the shifts in position of attenuation band in LPFG spectra. The shift in attenuation band is used to gauge the response of cladding modes LP₁₆, LP₁₇, LP₁₈, LP₁₉ and LP₂₀ possessing different grating periods. The LPFG is modeled on SMF28 optical fiber´s specifications and shift in attenuation band is studied over applied axial strain range of 0-1000 μs (micro strain). The strain sensitivities achieved by all modes are -0.113pm/μs, -0.18pm/μs, -0.22pm/μs, -0.12pm/μs and 2.88pm/μs respectively.