title: Fabrication of elliptic microfibers with CO2 laser for high-sensitivity refractive index sensing.
abstract: We propose a convenient method for achieving highly birefringent (HiBi) elliptic microfibers by use of the CO2-laser machining and the flame-brushing techniques. With optimization of fabrication process, a high birefringence of up to 2.10×10(-2) is experimentally obtained. Especially, within a polarization Sagnac interferometer acting as a refractive index (RI) sensor, both positive and abnormal negative sensitivity is measured, dependent on the geometrical variables of the HiBi microfiber. The maximum RI sensitivity is ∼195,348  nm/RI-unit around RI=1.35887, which is the highest among the microfiber devices as reported, to our knowledge.
authors: Li-Peng
authors: LP
authors: Sun
authors: Jie
authors: J
authors: Li
authors: Shuai
authors: S
authors: Gao
authors: Long
authors: L
authors: Jin
authors: Yang
authors: Y
authors: Ran
authors: Bai-Ou
authors: BO
authors: Guan