Opt Express. 2023 Feb 13;31(4):6917-6924. doi: 10.1364/OE.481253.
Fiber-optic sensors are an indispensable element of modern sensing technologies by virtue of their low cost, excellent electromagnetic immunity, and remote sensing capability. Optical Vernier effect is widely used to enhance sensitivity of fiber-optic sensors but requires bulky and complex cascaded interferometers. Here we propose and experimentally demonstrate an ultracompact (∼2 mm by ∼2 mm) Vernier-effect-improved sensor by only using a single microfiber-knot resonator. With the Vernier effect achieved by controlling the optical beating with the spectral ripple of a super light emitting diode (SLED), we show ∼20x sensitivity enhancement for quantitative temperature monitoring. Our sensor creates a new practical method to realize Vernier effect in fiber-optic sensors and beyond.
光纤传感器凭借其低成本、优异的电磁抗干扰性和远程传感能力，成为现代传感技术中不可或缺的组成部分。光学游标效应被广泛用于提高光纤传感器的灵敏度，但需要庞大而复杂的级联干涉仪。在这里，我们提出并实验证明了一种超紧凑的（∼2mm×∼2mm）游标效应改进型传感器，仅使用单个微光纤结谐振器。通过控制超辐射发光二极管（SLED）光谱波纹的光学拍频实现游标效应，我们实现了定量温度监测的∼20 倍灵敏度增强。我们的传感器为光纤传感器及其他领域实现游标效应创造了一种新的实用方法。
