光放大外腔式光纤法布里-珀罗干涉传感系统

提出了一种大幅度提高外腔式法布里珀罗干涉传感器干涉信号强度的方法 ,利用掺铒光纤放大自发辐射产生的光源代替一般宽带光源 ,同时由于掺铒光纤的放大作用可以放大干涉信号 ,将光纤法布里珀罗传感器的信号强度提高了 4个数量级 ,因而利用该方法可获得很强的信号和较高的信噪比。介绍了基于光放大的外腔式法布里珀罗干涉传感系统的结构、测量原理及实验。实验结果表明该传感器的应变精度为± 10 με,可满足实际应用的要求。该传感系统在大幅度提高传感器信号强度的同时并未提高系统的成本 ,因此有着较高的性价比和实用价值。

A Novel Extrinsic Fiber-Optic Fabry-Perot Interferometric Sensing System Based on Optical Amplification

A novel method of enhancing the signal level of extrinsic fiber-optic Fabry-Perot interferometer (EFPI) is proposed and demonstrated. This method is based on the simultaneous use of the amplified spontaneous emission (ASE) and optical amplification of an erbium-doped fiber (EDF) pumped by a 980 nm laser diode. The improvement in interferometric signal level is very significant as an enhancement of 4 orders of magnitude can be achieved. An experiment is carried out to verify this concept. An improvement of 43 dB in signal level has been achieved with a small pump power of ～30 mW. The strain accuracy has been improved by a factor of two compared with authors' previous EFPI system without optical amplification. Such an EFPI system has a good performance-to-price ratio since it can enhance the optical intensity greatly while it doesn't increase the cost of the sensor system significantly.