title: All-fiber add-drop filters based on microfiber knot resonators.
abstract: We demonstrate an all-fiber add-drop filter composed of a microfiber knot (working as a resonator) and a fiber taper (working as a dropping fiber). The dropping taper can be either parallel or perpendicular to the input port of the filter. A quality factor (Q factor) of 13,000 is obtained from a parallel-coupling 308 microm diameter microknot add-drop filter with a free spectral range (FSR) of 1.8 nm. A Q factor of approximately 3300 is obtained from a cross-coupling 65 microm diameter microknot add-drop filter with a FSR of 8.1 nm. This device is particularly easy to fabricate and to connect to fiber systems.
authors.affiliation: Department of Optical Engineering, Zhejiang University, Hangzhou, China.
authors.forename: Xiaoshun
authors.initials: X
authors.lastname: Jiang
authors.forename: Yuan
authors.initials: Y
authors.lastname: Chen
authors.forename: Guillaume
authors.initials: G
authors.lastname: Vienne
authors.forename: Limin
authors.initials: L
authors.lastname: Tong