光流控传感器及其应用

Optofluidic sensors and their applications

基于光流控技术,通过设计不同的芯片结构,可以制造出性能优异的光流控传感器。根据光流控传感器的芯片结构,可以将其分为4大类：前2类为基于光子晶体谐振腔的光流控传感器和基于回音壁模式的光流控传感器,流体在流经这2种传感器中的腔体结构时,产生的折射率改变会引起腔体耦合模式的变化,从而使光响应信号产生改变,起到传感作用;第3类为基于光波导模式的光流控传感器,光在波导中全反射产生的條逝场会与流体发生相互作用,令光信号产生变化;第4类为基于表面等离子体共振的光流控传感器,它利用表面等离子共振对金属表面区域折射率的敏感性实现传感功能,流体带来的折射率变化会令共振峰发生偏移。本文综述了以上4类光流控传感器芯片的结构、原理及应用。光流控传感器对于微小的折射率变化十分敏感,具有很高的灵敏度和精准度,同时,光流控系统本身具有低成本、小型化、结构简洁及实时调控的特征。随着未来被探测物体趋于微观,光流控传感器在物质探测和生物物质探测领域将发挥越来越强大的作用。

Based on the optofluidic technology,many kinds of high performance optofluidic sensors can be fabricated by different designs.The optofluidics sensors can be divided into four categories according to their structures.The first two categories are the optofluidic sensors based on the photonic crystal cavity and the whispering gallery mode.When the fluids flow through the cavities of the sensors,the couplemode will change because of the changed refractive index by the fluids,and the responding light signals will change as well.The third category optofluidic sensors are based on the optical waveguide.The fluids will interact with the evanescent field produced by the total reflection of the light in the optical waveguide,leading to the change of the responding light signals.The fourth category optofluidic sensors are based on the surface plasmon resonance.The sensors are very sensitive to the refractive index of the metal surface,and the refractive index changed by the fluids will shift the resonance peak.The optofluidic sensors are very sensitive to the changing of the refractive index,with high sensitivity and accuracy,meanwhile,the optofluidic system enjoys the advantages of low-cost,miniaturization and simple structure.As the detectors are approaching the microcosmic scale,the optofluidic sensors will play an important role in the detection and biochemical analysis area.