High Sensitivity Temperature Sensor Based on Liquid Packaged Microfiber Mode Interferometer

摘要

In this paper, a temperature sensor based on liquid packaged microfiber mode interferometer is proposed. The standard bare fibers are fabricated into microfiber mode interferometer by flame stretching technology, which is packaged in glass tubes and filled with deionized water as the outer layer of microfiber mode interferometer. The transmission characteristics of microfiber mode interferometer are modeled theoretically. The influence of device parameters on the transmission characteristics is analyzed. Based on the theoretical analysis, the temperature sensing characteristics of the hybrid liquid-encapsulated microfiber mode interferometer are experimentally verified. Because of the high negative thermal-optical coefficient of deionized water, the temperature sensor has high sensitivity. When the temperature sensor varies from 35.6 °C to 66.0 °C, the temperamental sensitivity of the device can reach -258.73 pm/°C. Through many experiments, the temperature sensitivity of the device varies in the range of 1.5%, which proves that the device has good stability. At the same time, the existence of liquid packaging can not only improve the temperature sensitivity of the device, but also prevent the sensing area from being polluted by surrounding materials such as dust, humidity and scratches so that the service life of the device is prolonged.