Temperature characteristics of a high sensitive dual side hole fiber

A dual side hole fiber (DSHF) with a pair of large air holes is proposed for free transducer temperature sensing in the infrared region (1500–1600 nm). The results of birefringence measurement based on a sagnac interferometer showed the linear group birefringence is from 4.35×10 -5 at 1500 nm, to 1.14×10 -4 at 1600 nm, respectively. The group birefringence of DSHF leads to a group temperature sensitivity from 3.9nm/°c at 1501nm to 1nm/°c at 1595nm, respectively.