Opt Lett. 2018 Jun 1;43(11):2499-2502. doi: 10.1364/OL.43.002499.
This Letter presents an ultrahigh resolution optic fiber strain sensor. A random distributed feedback fiber laser (RDFL) is locked by the proposed frequency-shift Pound-Drever-Hall technique, which tracks the resonant frequency change of a π-phase-shifted fiber Bragg grating. The random distributed feedback for the RDFL gives a Lorentzian envelope over the original laser frequency noise, which can suppress the thermally induced frequency noise. The frequency noise of the laser is reduced from about 100 to 20 Hz/√Hz at 1 kHz. An ultrahigh dynamic strain resolution of 140 fε/√Hz at 1 kHz is achieved.
这封信件介绍了一种超高分辨率光纤应变传感器。通过所提出的频移 Pound-Drever-Hall 技术锁定随机分布反馈光纤激光器（RDFL），该技术跟踪 π 相移光纤布拉格光栅的谐振频率变化。RDFL 的随机分布反馈在原始激光频率噪声上产生了一个洛伦兹包络，从而可以抑制热诱导的频率噪声。激光的频率噪声从大约 100 降低到 1 kHz 处的 20 Hz/√Hz。在 1 kHz 时实现了 140 fε/√Hz 的超高动态应变分辨率。
