Highly Sensitive Dual-Core Microstructured Fiber Sensor Operating Near the Dispersion Turning Point

In this article, a highly sensitive dual-core microstructured fiber (DC-MSF) sensor is proposed. Because of the adjustable dispersion characteristic of the DC-MSF, the group refractive index (RI) difference between the
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-polarization odd and even supermodes could achieve a zero value at the dispersion turning point (DTP), which makes the DC-MSF sensor have a high sensitivity. The simulation results show that the sensitivity can be up to 52 875 nm/RIU around the RI of 1.4, the operating bandwidth of sensitivity over 104 nm/RIU is 625 nm, and the operating bandwidth of sensitivity over 105 nm/RIU is 100 nm. Moreover, the DC-MSF can also be used as a temperature sensor by coating the polydimethylsiloxane (PDMS) on the surface, and the sensitivity can be up to 23.12 nm/°C around 22 °C. The detectable RI and temperature ranges of the proposed DC-MSF sensor are 1.375–1.425 and −15 °C–95 °C, respectively.