An optical fiber methane gas sensing film sensor based on core diameter mismatch
An optical fiber evanescent wave methane gas sensor based on core diameter mismatch is reported. The sensor consists of a multimode fiber in which a short section of standard single-mode fiber, coated with the inclusion of cryptophane molecules E in a transparent polysiloxane film, is inserted. The sensing principle is analyzed by optical waveguide theory. For different sensing film thicknesses and interaction lengths, the sensor signal is investigated within the methane concentration range of 0-14.5% (v/v). It is shown that the sensor signal with the thickness of 5 \mu m and the interaction length of 3 mm strengthens linearly with the increasing concentration of methane, with a slope of 0.0186. The best detection limit of the sensor for methane is 2.2% (v/v) with a response time of 90 s. This sensor is suitable for the detection of methane concentration below the critical value of 5%.
徐龙君：Key Laboratory for the Exploitation of Southwest Resources and Environmental Disaster Control Engineering, Ministry of Education, Chongqing University, Chongqing 400044, China
陈伟民：Key Laboratory for Optoelectronic Technology and Systems, Ministry of Education, College of Optoelectronic Engineering, Chongqing University, Chongqing 400044, China
备注：This work was supported by the National Natural Science Foundation of China (No. 60871039) and the Science and Technology Development Project of Chongqing (No. 2009AC6157).
【1】M. Tong, Catalytic Sensor and Application Technology (in Chinese) (China University of Mining and Technology Press, Xuzhou, 2002).
【2】M. Saha, A. Banerjee, A. K. Halder, J. Mondal, A. Sen, and H. S. Maiti, Sens. Actuat. B 79, 192 (2001).
【3】J. Qiao, H. F. Li, Y. Chang, L. S. Guan, S. Shuang, and C. Dong, Anal. Lett. 41, 593 (2008).
【4】H. Xia, W. Liu, Y. Zhang, R. Kan, M. Wang, Y. He, Y. Cui, J. Ruan, and H. Geng, Chin. Opt. Lett. 6, 437(2008).
【5】T. Wang, L. Zhang, L. Dong, H. Dou, and S. Jia, Chinese J. Lasers (in Chinese) 33, 405 (2006).
【6】J. Yang, L. Xu, and P. Zhang, Opt. Technique (in Chinese) 34, 562 (2008).
【7】H. Tai, H. Tanaka, and T. Yoshino, Opt. Lett. 12, 437(1987).
【8】B. Culshaw, F. Muhammad, G. Stewart, S. Murray, D. Pinchbeck, J. Norris, S. Cassidy, M. Wilkinson, D. Williams, I. Crisp, R. Van Ewyk, and A. McGhee, Electron. Lett. 28, 2232 (1992).
【9】S. Wu, Y. Zhang, Z. Li, S. Shuang, C. Dong, and M. M. F. Choi, Anal. Chim. Acta 633, 238 (2009).
【10】V. Kumar and D. Chandra, Proc. SPIE 3897, 139(1999).
【11】M. Benounis, N. Jaffrezic-Renault, J.-P. Dutasta, K. Cherif, and A. Abdelghani, Sens. Actuat. B 107, 32(2005).
【12】J. Yang, L. Xu, P. Zhang, and W. Chen, Acta Opt. Sin. (in Chinese) 29, 1183 (2009).
【13】S. K. Khijwania and B. D. Gupta, Opt. Quantum Electron. 31, 625 (1999).
【14】B. Wei and X. Sheng, (eds.) Principles and Application of Laser (in Chinese) (Chongqing University Press, Chongqing, 2007).
Jianchun Yang, Longjun Xu, Weimin Chen, "An optical fiber methane gas sensing film sensor based on core diameter mismatch," Chinese Optics Letters 8(5), 482-484 (2010)