College of Engineering and Applied Sciences and National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093, China.
Opt Lett. 2010 Jul 1;35(13):2308-10. doi: 10.1364/OL.35.002308.
We report an ultrasmall microfiber-probe-based reflective interferometer for highly sensitive liquid refractive index measurement. It has a 3.5 microm micronotch cavity fabricated by focused ion beam micromachining. A sensitivity of 110 nm/RIU (refractive index unit) in liquid is achieved with over 20 dB extinction ratio. Theoretical analysis shows this kind of device is a hybrid of Fabry-Perot and modal interferometers. In comparison with normal fiber interferometers, this probe sensor is very compact, stable, and cheap, offering great potentials for detecting inside sub-wavelength bubbles, droplets, or biocells.
我们报道了一种基于超小微光纤探针的反射式干涉仪，用于高灵敏度的液体折射率测量。它具有通过聚焦离子束微加工制造的 3.5 微米微槽腔。在液体中实现了 110nm/RIU（折射率单位）的灵敏度，超过 20dB 的消光比。理论分析表明，这种器件是法布里-珀罗和模态干涉仪的混合体。与普通光纤干涉仪相比，这种探针传感器非常紧凑、稳定且廉价，为检测亚波长气泡、液滴或生物细胞内部提供了巨大的潜力。
