Phase sensitivity of polarization-maintaining optical fiber used as temperature sensor

A method is given to calculate the thermal stress distributions in coated polarization-maintaining fibers. From the stresses, the phase sensitivities of these fibers are calculated. It is found that polarization-maintaining fibers do not offer any significant increase in phase sensitivity over conventional fiber. Coating with Silicone resin tends to reduce the sensitivity while the glass substrate (start tube) with higher thermal expansion coefficient than that of the cladding increases the sensitivity.