Open AccessCoreless side-polished fiber: a novel fiber structure for multimode interference and highly sensitive refractive index sensors
Author(s) -
Huazhuo Dong,
Liheng Chen,
Junjie Zhou,
Jianhui Yu,
Heyuan Guan,
Wentao Qiu,
Jiangli Dong,
Huihui Lu,
Jieyuan Tang,
Zhenhua Cai,
Yi Xiao,
Jun Zhang,
Zhe Chen
Publication year - 2017
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.25.005352
Subject(s) - multi mode optical fiber , cladding (metalworking) , materials science , optics , optical fiber , refractive index , beam propagation method , graded index fiber , optoelectronics , fiber optic sensor , physics , metallurgy
A novel fiber structure, coreless side-polished fiber (CSPF), is proposed and investigated to implement multimode interference (MMI) and high sensitive refractive index (RI) sensors. For such CSPF, the part of the cladding and the core of a single-mode fiber are side-polished off so as to make the remained cladding a D-shaped multimode waveguide. The excitation and evolution of MMI in the CSPF are simulated numerically. The simulation results show that the high-order modes excited within the D-shaped multimode waveguide are mainly TE 0,1 (TM 0,1 )~TE 0,6 (TM 0,6 ) modes. Moreover, the RI sensing characteristics and the influences of residual thickness and dip wavelength on the sensitivity are investigated both numerically and experimentally. The experimental results show that the CSPF with a residual thickness of 43.1 μm can reach an ultra-high sensitivity of 28000 nm/RIU in the RI range of 1.442~1.444. It is also found that the sensitivity can be further increased by reducing the residual thickness and choosing the dip at a longer wavelength. Thanks to the ultra-high RI sensitivity and the ease of fabrication, the CSPF could provide a cost-effective platform to build high-performance fiber devices of various functions.