Polarization-insensitive temperature sensor based on liquid filled photonic crystal fiber

In this paper, a polarization-insensitive temperature sensor based on photonic crystal fiber is proposed. Using finite element method, coupling between core and defected clad is analyzed. A high refractive index temperature sensitive liquid is infiltrated into the air holes of the second cladding ring. Numerical simulation shows as the phase matching between core and defect-clad super modes satisfied, resonance and peak confinement loss happen. A blue shift in resonance wavelength is obtained when temperature increases. Excellent linearity, simplicity and symmetrical structure, FOM of −0.272/°C and especially the same sensitivity of −1.96 nm/°C for both X and Y polarizations make the peak loss wavelength more detectable.