Fibre-optic micro-ring-resonator with 2 mm diameter

Abstract

We report the manufacturing and measurement of a fibre micro-ring absorption resonator for λ =1.55 μm with a biconical reduced fibre diameter down to 8.5 μm. The small ring diameter of 2 mm exhibits a large FSR of 30 GHz. From the optical frequency response a finesse of 4.7 and an insertion loss of l.2 dB were measured and the power coupling coefficient was calculated to be 0.28. To our knowledge, this is the smallest optical ring resonator reported so far.