基于光流控光纤激光器的折射率传感

A Fiber Optofluidic Laser for Refractive Index Sensing

本研究展示了一种基于回音壁模式(Whispering Gallery Mode, WGM)的光纤光流控激光器(Fiber optofluidic laser, FOFL),以罗丹明640(Rhodamine 640,Rh640)的乙醇水溶液构成激光增益介质,研究了光纤光流控激光器的激光光谱和阈值特性。此外,将FOFL应用于折射率传感,通过监测Rh640激光的波长漂移,实现了对微量溶液样品折射率的检测。结果表明,激光传感灵敏度约为1193.08 nm/RIU,与相同条件下的荧光传感方式相比,灵敏度提高了7倍。展示的FOFL具有制作简便、密封性好且样品消耗低等特点,可为有毒有害、易挥发物质的检测提供一种理想的平台。

In this paper, we demonstrate a whispering gallery mode(WGM)-based fiber optofluidic laser(FOFL), in which rhodamine 640(Rh640) in an ethanol aqueous solution is used as the laser gain medium. The laser spectra and threshold properties of the FOFL are investigated,respectively. In addition, we apply this FOFL platform to the refractive index sensing with a small analyte volume by monitoring the laser wavelength shift. The results show that the sensitivity can be up to 1193.08 nm/RIU, which exhibits seven folds improvement in sensitivity compared to the fluorescence measurement due to the signal amplification inherent to the lasing process. The proposed FOFL shows low sample consumption and easy to fabricate, providing an ideal sensing platform for various environmental and bio-chemical detection.