Enhanced Refractive Index and Inertial Sensing in a Multicoil Resonator Based on Microfiber

The multicoil resonator based on microfiber possesses a three-dimensional configuration in which the entire cavity is situated within the coupling region, such that its resonant modes are not only related to the transmission phase, but also affected by the coupled state. Therefore, the transmission of light in the multicoil resonator and its sensitivity enhancement in refractive index and inertial sensing are explored. The sensitivity enhancement for refractive index sensing in an MCR can be significantly improved up to 2.5 when the MCR has more than 6 turns. Moreover, this sensitivity enhancement is expected to remain consistent for inertial sensing.