基于单模多模单模（SMS）光纤输出光功率随温度的变化规律，提出了一种温度测量的理论模型，并实现了一种新型的测温系统。通过测量光功率变化的相位即可得到与之呈线性关系的温度变化。通过两个温度变化过程对该系统进行定标，得到相位与温度之间的定标系数为2.5347。对自然快速升温和线性缓慢升温两个过程进行了实验测试，系统误差小于5%。

A theoretical model is proposed and a novel system is built for measuring temperature based on the change rule for output power of single-mode-multimode-single-mode (SMS) fiber with temperature. The new measuring system can get the variation of the temperature which has a linear relationship with the output power by measuring the phase change of the output power. The calibration coefficient between the phase and the temperature is 2.5347 for a particular SMS fiber by comparing the two temperature variation. Then, a naturally rapid warming and a linearly slow warming of the temperature are checked by the SMS fiber and a thermometer. It is shown that the error is less than 5%.