On-chip Optofluidic Structure for Hormonal Detection Using Stable Fabry-Pérot Resonator

This work aims to present the numerical simulation of a micro-optical system consisting of a Fabry-Pérot resonator and micro-lenses used for hormonal detection. Ideally, the Fabry-Pérot cavity should have curved shape in 3D to confine the light in all directions inside the resonator. However, this 3D structure is not compatible with the planar microfabrication technology. Therefore, the design introduced in this work consists of an upright cylindrical lens and Fiber rod lens to confine the light in both horizontal and vertical directions before entering the cavity. The fabricated structure also includes a microfluidic channel that holds the fluid to be tested between the mirrors of the cavity. Both fluid mechanics simulations and optical simulations are conducted. The designed chip incorporates different Fabry-Pérot cavities that can be used to characterize different samples on the same chip with different sensitivities and detection ranges. The sensitivity of our device was tested by Estrogen hormone with different concentrations, and it is found to reach up to 400.25 nm/RIU.