Enhanced sensitivity of temperature sensor by a novel birefringent photonic crystal fiber with PDMS filling

It is more than important to sensitively take the temperature in industrial production and experimental study. In this paper, the high-sensitivity temperature sensor based on high birefringent photonic crystal fiber is proposed. To increase the sensitivity, polydimethylsiloxane (PDMS) was filled into the internal elliptical air hole of the photonic crystal fiber (PCF) to propose the PDMS/silica hybrid PCF structures. Temperature is measured by the quantitative change in birefringence of the refractive index of the PDMS material with temperature. We designed it as a detection loop and obtain the temperature detection sensitivity of up to 8.01 nm/°C in the range of −20 °C–20 °C, which was 6.5 times higher compared to the sensitivity obtained by filling with ethanol. This enables the designed PCF temperature sensor to be used for real-time and accurate temperature monitoring in the fields of bio-detection, chemistry, pharmaceuticals, etc. •A birefringent photonic crystal fiber structure is proposed, which has great application potential in temperature detection.•The temperature detection sensitivity was improved 6.5 times than that of filling ethanol.•In the designed optical fiber loop, the temperature range can be adjusted by adjusting the length of the optical fiber.