Systematic method for modeling and designing of an optofluidic sensor to measure the pressure and flow rate

In this paper, we present a new method for designing an optofluidic interferometric sensor to measure the pressure and flow rate based on generated optical ring pattern. This sensor consists of a flexible air gap optical cavity whose curvature depends on the pressure. When illuminated by a monochromatic light, the curved surface generates the interference patterns. In our numerical simulations, we take the effects of fluid flow rate, solid deformation, and the light interference into account. We use the beam propagation method (BPM) for simulating the optics and the finite element method (FEM) for simulating the mechanics. This pressure sensor was demonstrated in the working range of 0-60Pa at the constant temperature of 20 C.