Cheng Yunjie, Wang Yiping, Song Zixuan, Lei Jing
Opt Express. 2020 Nov 9;28(23):35264-35271. doi: 10.1364/OE.410922.
In this paper, a high-sensitivity optical fiber temperature sensor based on a dual-loop optoelectronic oscillator (OEO) with the Vernier effect has been proposed and experimentally demonstrated. Different from the traditional dual-loop OEOs which comprise a very long loop and a short loop to achieve low-phase noise and single-mode selection, the proposed OEO scheme has two loops with slightly different lengths and does not use any RF filters. A part of the fiber in one of the loops is used as a temperature sensing element as well as the delaying component. An obvious Vernier effect has been generated in the frequency response of the OEO. By detecting the frequency shift of the envelope peak of the measured frequency response curve, the temperature sensing interrogation of the dual-loop OEO based sensor is conducted. The experimental results show that the sensitivity of the proposed dual-loop OEO based temperature sensor can be improved from 6.625 KHz/°C for a single-loop OEO to 210.25KHz/°C by employing the Vernier effect.
本文提出并通过实验验证了一种基于具有游标效应的双环光电振荡器（OEO）的高灵敏度光纤温度传感器。与传统的双环OEO不同，传统双环OEO由一个很长的环和一个短环组成以实现低相位噪声和单模选择，本文提出的OEO方案有两个长度略有不同的环，并且不使用任何射频滤波器。其中一个环中的一部分光纤既用作温度传感元件又用作延迟元件。在OEO的频率响应中产生了明显的游标效应。通过检测测量的频率响应曲线包络峰值的频移，对基于双环OEO的传感器进行温度传感询问。实验结果表明，采用游标效应后，所提出的基于双环OEO的温度传感器的灵敏度可以从单环OEO的6.625KHz/°C提高到210.25KHz/°C。
