Temperature insensitive birefringent holey fiber

We analyzed theoretically the spectral dependence of susceptibility of phase modal birefringence to temperature dB/dT and polarimetric sensitivity to temperature KT in several glass-air photonic crystal holey fibers of different constructions. Contribution to dB/dT related to thermal expansions of the analyzed structure and that related to temperature-induced changes in refractive indices of the glass and the air were calculated separately. Our results show that the overall sensitivity dB/dT highly depends on the geometry of the birefringent holey fiber. We also demonstrate that by proper choice of the fiber geometry, it is possible to significantly reduce its response to temperature and even to achieve zero sensitivity at specific wavelength. We measured KT and identified its sign for two analyzed silica-air fibers. The measured values of sensitivity are in good agreement with the results of modeling.