title: Controlling the resonance of a photonic crystal microcavity by a near-field probe.
abstract: We demonstrate theoretically that the resonance frequencies of high-Q microcavities in two-dimensional photonic crystal membranes can be tuned over a wide range by introducing a subwavelength dielectric tip into the cavity mode. Three-dimensional finite-difference time-domain simulations show that by varying the lateral and vertical positions of the tip, it is possible to tune the resonator frequency without lowering the quality factor. Excellent agreement with a perturbative theory is obtained, showing that the tuning range is limited by the ratio of the cavity mode volume to the effective polarizability of the nanoperturber.
authors.affiliation: Laboratory of Physical Chemistry, Swiss Federal Institute of Technology (ETH), 8093 Zürich, Switzerland.
authors.forename: A Femius
authors.initials: AF
authors.lastname: Koenderink
authors.forename: Maria
authors.initials: M
authors.lastname: Kafesaki
authors.forename: Ben C
authors.initials: BC
authors.lastname: Buchler
authors.forename: Vahid
authors.initials: V
authors.lastname: Sandoghdar