title: Influence of a sharp fiber tip on high-Q modes of a microsphere resonator.
abstract: We investigate the degradation of the Q factor of a fundamental whispering-gallery mode of a microsphere resonator when a fiber tip is placed in the evanescent field of the mode. With a tip diameter of 80 nm it is possible to maintain a Q factor exceeding 10(8), even when the tip is as close as 10 nm to the sphere surface. This result demonstrates the possibility of using such a tip as a "nanotool" to actively place a single nanoparticle in a single high- Q mode with great precision to achieve well-controlled coupling.
authors.forename: S
authors.initials: S
authors.lastname: Götzinger
authors.forename: O
authors.initials: O
authors.lastname: Benson
authors.forename: V
authors.initials: V
authors.lastname: Sandoghdar