Embedded Optical Microfiber Coil Resonator With Enhanced High-$Q$

We successfully fabricate a uniform cylindrical microfiber coil resonator by wrapping a very thin strand of microfiber on a support rod and embedding/packaging it with a low refractive index polymer. An improved
Q
-factor in excess of 220 000 and an extinction ratio of 11.5 dB are achieved due to nearly ideal coupling and phase matching between the adjacent turns. The
Q
-factor is the highest reported value to date for any microfiber-based resonators.