title: Tunable refractive index sensor with ultracompact structure twisted by poly(trimethylene terephthalate) nanowires.
abstract: We report a tunable refractive index sensor with ultracompact structure in a 2 x 2 poly(trimethylene terephthalate) (PTT) nanowire coupling splitter assembled by twisting two flexible PTT nanowires. The sensor consists of two input branches, a twisted coupling region, and two output branches. The changes of optical power caused due to variations in the surrounding medium around the twisted coupling region were measured in the output branches. The highest measured sensitivity of the sensor is 26.96 mW/RIU (refractive index unit) and the maximum detection limit on refractive index change is 1.85 x 10(-7). The average tunabilities observed are 1.2 mW per RIU per twisted turn and 1.8 mW per RIU per 5 degrees branching angle change.
authors.affiliation: State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-Sen University, Guangzhou 510275, China.
authors.forename: Heng
authors.initials: H
authors.lastname: Zhu
authors.forename: Yuqing
authors.initials: Y
authors.lastname: Wang
authors.forename: Baojun
authors.initials: B
authors.lastname: Li
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000295:instrumentation*; D008853:Microscopy; D053770:Nanowires / Q000737:chemistry*; D011093:Polyethylene Terephthalates / Q000737:chemistry*; D012399:Rotation
chemical_list: D011093:Polyethylene Terephthalates; C498323:poly(trimethylene terephthalate)