Temperature and pressure sensitivities of the highly birefringent photonic crystal fiber with core asymmetry

We investigated a particular design of a highly birefringent PCF with attractive features for pressure sensing applications. A plane-wave method together with the finite element method were used to numerically calculate phase and group modal birefringence, pressure and temperature sensitivities of our fiber. The simulation results together with the experiments demonstrate a considerable difference between a very high phase birefringence (B similar to 10(-3)) and a very low negative group birefringence (G similar to -10(-3)). Our fiber exhibits a low and positive temperature sensitivity (K-T < 0.1 rad/(K center dot m)), and relatively high and negative mechanical (pressure) sensitivity (K-p <= -10 rad/(MPa center dot m)), which supports its possible use as a mechanical sensor that does not require any temperature compensation.