Abstract

We demonstrate aqueous refractive index sensing with 15–30 μm diameter silicon nitride microdisk resonators to detect small concentrations of Li salt. A dimpled
silicon nitride membrane is used to form a microdisk resonator with a high quality factor (Q) of ~10,000. The Li salt is detected by monitoring the shift in resonance frequency of the microdisk resonator as a function of Li concentration. The Li salt concentration is determined to be ~0.1 M with a