Highly sensitive refractive index fiber inline Mach–Zehnder interferometer fabricated by femtosecond laser micromachining and chemical etching》.pdfVIP

Optics Laser Technology 77 (2016) 11–15 Contents lists available at ScienceDirect Optics Laser Technology journal homepage: /locate/optlastec Highly sensitive refractive index fiber inline Mach–Zehnder interferometer fabricated by femtosecond laser micromachining and chemical etching $ Xiao-Yan Sun, Dong-Kai Chu, Xin-Ran Dong, Chu-Zhou, Hai-Tao Li, Luo-Zhi, You-Wang Hu, Jian-Ying Zhou, Cong-Wang, Ji-An Duan n State Key Laboratory of High Performance Complex Manufacturing, College of Mechanical and Electrical Engineering, Central South University, 932 South Lushan Street, Changsha 410083, China a r t i c l e i n f o a b s t r a c t Article history: A High sensitive refractive index (RI) sensor based on Mach–Zehnder interferometer (MZI) in a con- Received 15 June 2015 ventional single-mode optical fiber is proposed, which is fabricated by femtosecond laser transversal- Received in revised form scanning inscription method and chemical etching. A rectangular cavity structure is formed in part of 9 July 2015 fiber core and cladding interface. The MZI sensor shows excellent refractive index sensitivity and line- Accepted 21 July 2015 arity, which exhibits an extremely high RI sensitivity of 17197 nm/RIU (refractive index unit) with the linearity of 0.9996 within the refractive index range of 1.3371–1.3407. The experimental results are Keywords: cons