A gold film coated dual-core photonic crystal fiber for refractive index and temperature sensing with high isolation

Abstract

• When measuring RI of an analyte, the measurement is often affected by temperature. the simultaneous measurement of RI and temperature has important significance. • In this paper, a gold film coated dual-core photonic crystal fiber (DC-PCF) was proposed and numerically investigated for both RI and temperature sensing. • The maximum sensitivity of the RI reached 8100 nm/RIU, while the maximum sensitivity of temperature reached 1.3 nm/°C. • The design of dual independent cores in DC-PCF not only avoids the problem of cross-sensitivity; but also improves the isolation of the sensor. When measuring the refractive index (RI) of an analyte, the measurement is often affected by temperature. Therefore, the simultaneous measurement of RI and temperature has important research significance. In this paper, a gold film coated dual-core photonic crystal fiber (DC-PCF) was proposed and numerically investigated for both RI and temperature sensing. In order to stimulate the surface plasmon resonance (SPR) with high sensitivity to the surrounding, two gold films were coated on the polished surface and inner wall of a cladding air hole in the DC-PCF, respectively. Numerical results showed that the measurement sensitivities of RI and temperature reached 8100 nm/RIU based on Core I and 1.3 nm/°C based on Core II, respectively. It should also be noted that the designed sensor showed a high isolation. This designed sensor can be used where the RI of analyte should be detected at a high temperature accuracy.