title: Effects of surface roughness on optical properties and sensitivity of fiber-optic evanescent wave sensors.
abstract: The effects of surface roughness on the light transmission properties and sensitivity of fiber-optic evanescent wave sensors are investigated. A simple method of increasing the sensitivity based on the surface roughness (pit depth δ and diameter Δ) and incident angle U(i) of light rays on the fiber input end is proposed. We discovered that as 2δ/Δ increases, the transmitted light intensity decreases, but the sensitivity initially increases and then decreases. In sensors containing fibers of various roughnesses, the sensitivity to glucose solutions reached -11.7 mW/riu at 2δ/Δ=0.32 and increased further to -15.3 mW/riu with proper adjustment of U(i).
authors.affiliation: Key Laboratory of Low-grade Energy Utilization Technologies and Systems (Chongqing University), Ministry of Education, Chongqing, China.
authors.forename: Nianbing
authors.initials: N
authors.lastname: Zhong
authors.forename: Xun
authors.initials: X
authors.lastname: Zhu
authors.forename: Qiang
authors.initials: Q
authors.lastname: Liao
authors.forename: Yongzhong
authors.initials: Y
authors.lastname: Wang
authors.forename: Rong
authors.initials: R
authors.lastname: Chen
authors.forename: Yahui
authors.initials: Y
authors.lastname: Sun