Temperature-compensated dual-polarization fiber grating laser sensors

We report on temperature compensation for beat-frequency-encoded dual-polarization fiber laser sensors based on a cleave-rotate-splice method. By cleaving the laser cavity into two segments with comparable lengths, aligning them with a rotated angle of 90 degrees, and then fusion splicing the two halves, the temperature sensitivity in terms of beat-frequency variation can be greatly reduced from -1.99 to -0.30 MHz/degrees C (or by 84.9%). In contrast, the sensitivity to point loaded mass hardly changes. We also find that the beat-frequency fluctuation decreases from perpendicular to 30 to perpendicular to 25 kHz as a result of the temperature compensation.