Simultaneous measurement of temperature and refractive index based on a core-offset Mach-Zehnder interferometer cascaded with a long-period fiber grating

Abstract

An all-fiber sensor based on a cascaded optical fiber device is proposed and demonstrated, and its sensor head is composed of a core-offset Mach-Zehnder interferometer (MZI) and a long-period fiber grating (LPFG). In the experiment, two dips shaped by the intermodulation between the interference fringe of MZI and the resonant wavelength of LPFG are monitored. Experimental results show that temperature sensitivities of two dips are 0.060 7 nm/°C and 0.056 3 pm/°C, and the refractive index (RI) sensitivities are −18.025 nm/RIU and −55.06 nm/RIU, respectively. The simultaneous measurement of the temperature and external RI is demonstrated based on the sensitive matrix. Its low fabrication cost, simple configuration and high sensitivity make this sensor have potential applications in chemical and biological sensing.

Keywords

Fiber Bragg Grating / Core Mode / Single Mode Fiber / Resonant Wavelength / Sensor Head

References

[1] OuQ-b, ZengQ-k, QingZ-x, LiC-q. Journal of Optoelectronics·Laser, 2013, 24: 323

[2] ShiJ, XiaoS, BiM, YiL, YangP. Applied Optics, 2012, 51: 2733

[3] ShiS-h, ZhouX-j, ZhangZ-y, LiuY. Journal of Optoelectronics·Laser, 2012, 23: 1644

[4] WuQ, SemenovaY, WangP, FarrellG. Optics Express, 2011, 19: 7937

[5] ZhouJ, WangY, LiaoC, YinG, XuX, YangK, ZhongX, WangQ, LiZ. IEEE Photonics Technology Letters, 2014, 26: 508

[6] GongH, YangX, NiK, ZhaoC-L, DongX. IEEE Photonics Technology Letters, 2014, 26: 22

[7] TianZ, YamS S-H, LoockH-P. IEEE Photonics Technology Letters, 2008, 20: 1387

[8] LiL, LiX, XieZ, LiaoZ, TuF, LiuD. Optics Communications, 2012, 285: 3945

[9] ShenC-Y, ChuJ-L, LuY-F, ChenD-B, ZhongC, LiY, DongX-Y, JinS-Z. IEEE Photonics Technology Letters, 2014, 26: 62

[10] LiJ, ZhangW, GaoS, GengP, XueX, BaiZ, LiangH. IEEE Photonics Technology Letters, 2013, 25: 888

[11] YaoQ, MengH, WangW, XueH, XiongR, HuangB, TanC, HuangX. Sensors and Actuators A: Physical, 2014, 209: 73

[12] GuZ, JiangX, ChenH. Optical Engineering, 2014, 53: 021104

[13] TianZ, YamS S-H. Journal of Lightwave Technology, 2009, 27: 2296

[14] MaoL, LuP, LaoZ, LiuD, ZhangJ. Optics & Laser Technology, 2014, 57: 39

[15] HuX-l, LiangD-k, FangT, WangY, LiD. Journal of Optoelectronics·Laser, 2012, 23: 1659