Microcavity confinement based on an anomalous zero group-velocity waveguide mode.
We propose and demonstrate a mechanism for small-modal-volume high-Q cavities based on an anomalous uniform waveguide mode that has zero group velocity at a nonzero wave vector. In a short piece of a uniform waveguide with a specially designed cross section, light is confined longitudinally by small group-velocity propagation and transversely by a reflective cladding. The quality factor Q is greatly enhanced by the small group velocity for a set of cavity lengths that are separated by approximately pi/k0, where k0 is the longitudinal wave vector for which the group velocity is zero.
Ibanescu
Mihai
M
Center for Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA. michel@mit.edu
Johnson
Steven G
SG
Roundy
David
D
Fink
Yoel
Y
Joannopoulos
J D
JD