Novel temperature-independent microfiber sensor fabricated with the tapering-twisting-tapering technique.

In this paper, a novel twist and refractive index microfiber sensor fabricated with the tapering-twisting-tapering technique has been proposed and demonstrated, for the first time to the best of our knowledge. Experimental results show that the interference intensity of the microfiber increases with the increment of pre-tapered length and the intervening twist number. The sensitivity of the microfiber sensor with respect to twist is found to be 2.817 dB/(rad/m) and the refractive index sensitivity of this microfiber sensor can reach to ∼809  nm/refractive index unit in the refractive index ranging from 1.30 to 1.33. Moreover, considering that its temperature sensitivity is 0.005 dB/°C, it will not suffer from the cross sensitivity to temperature.