Cerenkov Radiation in Photonic Crystals
Chiyan Luo,
Mihai Ibanescu,
Steven G. Johnson,
J. D. Joannopoulos*
In a conventional material, the coherent Cerenkov radiation due to
a moving charged particle is associated with a velocity threshold, a
forward-pointing radiation cone, and a forward direction of emission.
We describe different behavior for the Cerenkov radiation in a photonic
crystal. In particular, this radiation is intrinsically coupled with
transition radiation and is observable without any threshold. Within
one particle-velocity range, we found a radiation pattern with a
backward-pointing radiation cone. In another velocity range,
backward-propagating Cerenkov radiation can be expected. Potential
applications include velocity-sensitive particle detection and
radiation generation at selectable frequencies.
Department of Physics and Center for Materials Science and
Engineering, Massachusetts Institute of Technology, Cambridge, MA
02139, USA.
*
To whom correspondence should be addressed. E-mail:
joannop{at}mit.edu
