Bare fiber adapter based Fabry-Perot interferometer for microfluidic velocity measurement

摘要

A fiber microfluidic velocity sensor based on a bare fiber adapter (BFA) was proposed and demonstrated. Ceramic end face in BFA was covered by polyethylene (PE) film, in which the inserted single mode fiber (SMF) can be moved freely. The end face of the SMF and the PE film composed a Fabry-Perot (F-P) construction. Due to PE film sustaining different press with different microfluidic velocity, the F-P cavity length was changed. The velocity can be measured by monitoring the reflection spectrum. In our experiment, three cavity lengths were measured. The experimental results showed that the achieved maximum sensitivity to microfluidic velocity is 0.048 dB/(mu L/min) or 0.0059 nm/(mu L/min). Also, responses of PE film thickness and microfluidic concentration to the proposed sensor have been measured in the experiment. The sensor can be used for low velocity with high sensitivity, especially in micro-channels such as biological blood vessels.