A hybrid plasmonic microfiber knot resonator and mechanical applications

Abstract

In this work, a hybrid plasmonic microfiber knot resonator (HPMKR) is demonstrated as well as its multi-sense applications. A microfiber knot resonator (MKR) is attached to gold film and generates the hybrid plasmonic mode. The HPMKR has an extinction ratio of more than 10 dB in C-band, with the Q-factor of more than 47,000. For a chosen polarization, the resonator has an extinction ratio of nearly 15 dB, even though the diameter of the microfiber is more than 5 μm, which is unattainable for a normal MKR. We choose PDMS as the encapsulating material to package the device. Then the device can be utilized as a pressure sensor with sensitivity of 9.34 pm/kPa, and a vibration sensor with the range from tens of hertz to several kilohertz. And our sensor can also be utilized as a wearable health monitor.