A novel reflective refractometer based on a thin-core fiber (TCF) sandwiched between a leading single-mode fiber (SMF) and a fiber Bragg grating (FBG) imprinted SMF stub was demonstrated. The reflection from the fiber stub occurs in two well-defined wavelength bands, corresponding to the Bragg core mode and cladding modes. The TCF section functions as a tailorable bridge between the FBG core mode reflection and the surrounding refractive index (SRI). Linear response with enhanced sensitivity of 133.26 dB/refractive index unit for temperature-immune SRI measurement within the biologically desirable sensing range of 1.33–1.41 has been achieved via cost-effective power detection.
© 2012 Optical Society of America
Fiber Optics and Optical Communications
Original Manuscript: September 20, 2011
Revised Manuscript: December 8, 2011
Manuscript Accepted: December 9, 2011
Published: January 20, 2012
Yue Ma, Xueguang Qiao, Tuan Guo, Ruohui Wang, Jing Zhang, Yinyan Weng, Qiangzhou Rong, Manli Hu, and Zhongyao Feng, "Reflective fiber-optic refractometer based on a thin-core fiber tailored Bragg grating reflection," Opt. Lett. 37, 323-325 (2012)