Polarization sensitivities of demodulation techniques for tilted fiber Bragg Grating refractometer

The polarization sensitivities of demodulation techniques for tilted fiber Bragg Grating (TFBG) refractometer are investigated theoretically. It shows that the normalized area detecting technique is polarization insensitive; the power-referenced demodulation technique is highly polarization sensitive, the polarization sensitivity increases with the grating tilted angle, thus, precise polarization control is essential.