title: Ultrasensitive refractive-index sensors based on rectangular silica microfibers.
abstract: We demonstrate an ultrasensitive refractive-index (RI) sensor utilizing the polarimetric interference of a rectangular silica microfiber. The measured sensitivity is as high as 18,987 nm/RIU (refractive-index unit) around the RI of 1.33, which is 1 order of magnitude higher than that of the previously reported microfiber devices. Theoretical analysis reveals that such high sensitivity not only is originated from the RI-induced birefringence variation but also relies on the unique birefringence dispersion property for the rectangular microfiber. We predict that the sensitivity can be enhanced significantly when the group birefringence approaches zero.
authors.affiliation: Institute of Photonics Technology, Jinan University, Guangzhou, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Li
authors.forename: Li-Peng
authors.initials: LP
authors.lastname: Sun
authors.forename: Shuai
authors.initials: S
authors.lastname: Gao
authors.forename: Zhan
authors.initials: Z
authors.lastname: Quan
authors.forename: Yong-Liang
authors.initials: YL
authors.lastname: Chang
authors.forename: Yang
authors.initials: Y
authors.lastname: Ran
authors.forename: Long
authors.initials: L
authors.lastname: Jin
authors.forename: Bai-Ou
authors.initials: BO
authors.lastname: Guan
mesh_terms: D001718:Birefringence; D055100:Optical Fibers; D055620:Optical Phenomena; D012822:Silicon Dioxide / Q000737:chemistry
chemical_list: D012822:Silicon Dioxide