Simultaneous measurement of one dimensional bending and temperature based on Mach-Zehnder interferometer

Abstract

A simple and compact optical fiber directional bending vector sensor with simultaneous measurement of temperature based on the Mach-Zehnder interferometer (MZI) is proposed and experimentally demonstrated. The device consists of a piece of photonic crystal fiber (PCF) sandwiched between two single mode fibers (SMFs) with a lateral offset splicing. It shows the capacity for recognizing positive and negative directions. Within a curvature range of -7.13 m^-1 to 7.13 m^-1, the bending sensitivities of two resonant dips with opposite fiber orientations are obtained to be 0.484 nm/m^-1 and 0.246 nm/m^-1, respectively. This simple MZI is formed by invoking interference between LP₀₁ and LP₂₁ core modes, which leads to that the sensor is not sensitive to ambient refractive index (ARI). The temperature sensitivity has also been investigated. Two dips have obviously different sensitivities on the temperature and bending, so two parameters of both curvature and temperature can be distinguished and measured simultaneously by constructing a matrix and using one simple model interferometer.

Keywords

Fiber optics sensors / microstructured fiber / temperature sensor / curvature sensor

References

[1] Patrick H. J., Chang C., Vohra S. T.. Long period fiber gratings for structural bending sensing. Electronics Letters, 1998, 34(18): 1773-1775.

[2] Jin Y., Chan C., Dong X., Zhang Y.. Temperature-independent bending sensor with tilted fiber Bragg grating interacting with multimode fiber. Optics Communications, 2009, 282(19): 3905-3907.

[3] Shao L., Xiong L., Chen C., Laronche A., Albert J.. Directional bend sensor based on re-crown tilted fiber Bragg grating. Journal of Lightwave Technology, 2010, 28(18): 2681-2687.

[4] Deng M., Tang C., Zhu T., Rao Y.. Highly sensitive bend sensor based on Mach-Zehnder interferometer using photonic crystal fiber. Optics Communications, 2011, 284(12): 2849-2853.

[5] Monzon-Hernandez D., Martinez-Rios A., Torres-Gomez I., Salceda-Delgado G.. Compact optical fiber curvature sensor based on concatenating two tapers. Optics Letters, 2011, 36(22): 4380-4382.

[6] Frazão O., Viegas J., Caldas P., Santos J. L., Araújo F. M., Ferreira L. A., . All-fiber Mach-Zehnder curvature sensor based on multimode interference combined with a long-period grating. Optics Letters, 2007, 32(21): 3074-3076.

[7] Zhang S., Zhang W., Gao S., Geng P., Xue X.. Fiber-optic bending vector sensor based on Mach-Zehnder interferometer exploiting lateral-offset and up-taper. Optics Letters, 2012, 37(21): 4480-4482.

[8] Ou Z., Yu Y., Yan P., Wang J., Huang Q., Chen X., . Ambient refractive index-independent bending vector sensor based on seven-core photonic crystal fiber using lateral offset splicing. Optics Express, 2013, 21(20): 23812-23821.

[9] Zheng J., Yan P., Yu Y., Ou Z., Wang J., Chen X., . Temperature and index insensitive strain sensor based on a photonic crystal fiber in line Mach-Zehnder interferometer. Optics Communications, 2013, 297(15): 7-11.

[10] Geng Y., Li X., Tan X., Deng Y., Hong X.. Compact and ultrasensitive temperature sensor with a fully liquid-filled photonic crystal fiber Mach-Zehnder interferometer. IEEE Sensors Journal, 2013, 14(1): 167-170.

[11] Allsop T., Reeves R., Webb D. J., Bennion I., Neal R.. A high sensitivity refractometer based upon a long period grating Mach-Zehnder interferometer. Review of Scientific Instruments, 2002, 73(4): 1702-1705.

[12] Villatoro J., Minkovich V., Pruneri V., Badenes G.. Simple all-microstructured-optical-fiber interferometer built via fusion splicing. Optics Express, 2007, 15(4): 1491-1496.

[13] Frazão O., Silva S. F. O., Viegas J., Baptista J. M., Santos J. L., Kobelke J., . All fiber Mach-Zehnder interferometer based on suspended twin-core fiber. IEEE Photonics Technology Letters, 2010, 22(17): 1300-1302.

[14] Dong B., Hao J., Xu Z.. Temperature insensitive curvature measurement with a core-offset polarization maintaining photonic crystal fiber based interferometer. Optical Fiber Technology, 2011, 17(3): 233-235.

[15] Guzman-Sepulveda J. R., May-Arrioja D. A.. In-fiber directional coupler for high-sensitivity curvature measurement. Optics Express, 2013, 21(10): 11853-11861.

[16] Wu Z., Liu Y., Wang Z., Han T., Li S., Jiang M., . In-line Mach-Zehnder interferometer composed of microtaper and long-period grating in all-solid photonic bandgap fiber. Applied Physics Letters, 2012, 101(14): 141106-1–141106–4.