A high-sensitivity Mach-Zehnder(MZ) interferometric refractive index(RI) sensor based on two different ultra-abrupt tapers is proposed and demonstrated experimentally. The whole fabrication process is relatively simple. One taper is fabricated by the fusion-splicing method and the ratio of the waist diameter to the taper length is 1:1. The other taper is fabricated by CO2 laser irradiation with a ratio around 1:10. According to the experimental results, the spectral loss of the proposed MZ interferometric sensor has a linear response to the external RI change with a ultrahigh sensitivity of -412.02138 dB/RIU(refractive index unit) in the range of 1.3505-1.3684. The sensor has the potential application for RI measurement in chemical or biochemical sensing fields due to its low cost, simple structure and extremely high sensitivity.

Date Published: 19 February 2015
PDF: 6 pages
Proc. SPIE 9449, The International Conference on Photonics and Optical Engineering (icPOE 2014), 94491X (19 February 2015); doi: 10.1117/12.2074872

Published in SPIE Proceedings Vol. 9449:
The International Conference on Photonics and Optical Engineering (icPOE 2014)
Ailing Tian; Anand Asundi; Weiguo Liu; Chunmin Zhang, Editor(s)