Microbottle resonator formaldehyde sensor

Abstract

We investigate the use of whispering gallery mode (WGM) optical microbottle resonator (MBR) as a sensor for liquid formaldehyde sensor. An MBR fabricated via the "soften-and-compress" method with a diameter of 190 μm was optically excited by using a non-adiabatic 2 μm optical microfibre and employed to measure formaldehyde with concentrations of between 0% and 5%, with the results compared with the performance of a bare microfibre. The MBR sensor was found to have a sensitivity of 4.397 dB/% with 90 % linearity and were generally outperforms the bare microfiber sensor by a wide margin.