Highly sensitive temperature sensor based on surface plasmon resonance in a liquid-filled hollow-core negative-curvature fiber

We numerically investigated a novel temperature sensor, which utilized a liquid-filled and Au-coated hollow-core negative-curvature fiber. All the air holes in the fiber were filled with a temperature-sensitive liquid, while two cladding tubes were coated with Au films. As the temperature increased, the coupling wavelength between the core mode and surface plasmon polariton mode supported by the Au layer shifted. The temperature sensitivity was 2.860 nm/°C in the range of 20–40 °C, and the inner wall of double-sided cladding tubes were deposited with a 30 nm Au layer. The designed sensor shows a high sensitivity, which is suitable for temperature detection in industrial and biomedical applications.