Birefringent bragg grating in c-shaped optical fiber as a temperature-insensitive refractometer

• Main Authors: Tan, Rex Xiao, Ho, Daryl, Tse, Chun Ho, Tan, Yung Chuen, Yoo, Seong Woo, Tjin, Swee Chuan, Ibsen, Morten
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2018
• Subjects: Fiber Bragg Gratings; DRNTU::Engineering::Electrical and electronic engineering; Fiber Sensors
• Online Access: https://hdl.handle.net/10356/89578; http://hdl.handle.net/10220/46301
• Institution: Nanyang Technological University

We demonstrate a simple-to-fabricate refractometer based on the inscription of fiber Bragg gratings in a special C-shaped optical fiber. The C-shaped fiber was drawn into shape using a quarter cladding removed preform of a commercial standard single-mode fiber by simple machining. The sensor did not suffer from cross-sensitivity of the refractive index with ambient temperature fluctuations, commonly occurring with many optical fiber refractometers. A refractive index sensitivity of 1300 pm per refractive index unit (RIU) was achieved without employing any additional sensitization techniques such as tapering or etching.