Han Xile, Liu Weiru, Zu Lijiao, Wu Wen, Xie Jiwei, You Daotong, Du Minghui, Guo Tuan
Opt Lett. 2024 Feb 1;49(3):650-653. doi: 10.1364/OL.512335.
We propose a compact fiber-optic sensor for in situ and continuous turbidity monitoring, based on surface optical scattering of polarized evanescent waves from targeted particles. The sensor is composed of a tilted fiber Bragg grating (TFBG) packaged inside a microfluidic capillary. The transmission spectrum of the TFBG provides a fine comb of narrow cladding resonances that are highly sensitive to the turbidity due to the localized light scattering of polarized evanescent waves from the microparticles near the fiber surface (as opposed to traditional bulk/volumetric turbidity measurement). We also propose a transmission spectral area interrogation method and quantify the repeatable correlation between the surface turbidity and the optical spectral area response. We show that the maximum sensitive turbidity response is achieved when the wavelength of the sensing cladding resonance matches the size of surrounding solid particles.
我们提出了一种基于来自目标颗粒的偏振倏逝波的表面光散射的紧凑型光纤传感器，用于原位和连续浊度监测。该传感器由封装在微流体毛细管内的倾斜光纤布拉格光栅（TFBG）组成。TFBG的透射光谱提供了一组精细的窄包层共振梳状谱，由于光纤表面附近微粒的偏振倏逝波的局部光散射，这些共振对浊度高度敏感（与传统的体/体积浊度测量不同）。我们还提出了一种透射光谱面积询问方法，并量化了表面浊度与光谱面积响应之间的可重复相关性。我们表明，当传感包层共振波长与周围固体颗粒的尺寸匹配时，可实现最大灵敏的浊度响应。
