We demonstrated a simple technique for a highly sensitive temperature sensor based on an “S”-shape fiber taper Mach-Zehnder interferometer (MZI) with no need of special fibers or micromachining technique using high power lasers. To enhance the sensitivity, an S-shape single mode fiber (SMF) taper was encapsulated in a capillary filled with high thermos-optic coefficient liquid. We experimentally investigated the tuning parameters for the sensor, such as the taper shape, the material of the capillary, and the role of the filling liquid. Our results show a maximum sensitivity of −15.66 nm/°C in a measurement range of 28–32 °C, and −11.88 nm/°C from 25.1 °C to 35 °C for isopropanol sealed in Teflon capillary. The multi-interference model simulation shows that a critical cladding mode is responsible for the high sensitivity. Simple configuration, ease of fabrication, robustness and low cost make it suitable for high sensitivity temperature sensing applications.

我们展示了一种基于“ S”形光纤锥度马赫曾德尔干涉仪（MZI）的高灵敏度温度传感器的简单技术，不需要特殊的光纤或使用大功率激光器的微加工技术。为了提高灵敏度，将S形单模光纤（SMF）锥度封装在装有高热光系数液体的毛细管中。我们通过实验研究了传感器的调整参数，例如锥度形状，毛细管材料以及填充液的作用。我们的结果显示，在28-32°C的测量范围内，最大灵敏度为-15.66 nm /°C；对于密封在聚四氟乙烯毛细管中的异丙醇，从25.1°C至35°C，则为-11.88 nm /°C。多干扰模型仿真表明，临界包层模式是高灵敏度的原因。配置简单，