Development of a small-size embedded optical microfiber coil resonator with high Q

Abstract

We fabricate a small-size embedded optical microfiber coil resonators (OMCRs) with a high Q-factor and investigate the dependence of the transmission characteristics of the OMCRs on the microfiber diameter and the OMCR diameter. Various microfibers with different diameters of 2.0, 2.1, 2.2, and 2.3 A mu m are fabricated by using a micro-tapering technique and are then coiled onto silica support rods. OMCRs are embedded by using a polymer with a low refractive index. When a 2.1-A mu m-diameter microfiber is coiled around a 10-mm-diameter silica support, a Q-factor of 1.0 x 10(5) is obtained, and the free spectral range, the full width at half maximum, and the extinction ratio are measured to be 50 pm, 15 pm, and 3.8 dB, respectively. The Q-factor also has a strong dependence on the OMCR diameter.