ANTISYMMETRICAL OPTICAL STATES

The general properties of antisymmetrical solutions of the coupled-dipole equation are studied. This equation is used to describe the interaction of a cluster of small particles acting as elementary dipoles with an external electromagnetic wave. It is shown that antisymmetrical (with zero total dipole moment) eigenstates can be excited even in clusters that are much smaller in size than the wavelength of the incident radiation. Ttl this case the quality of the collective optical resonance may be enhanced by the large parameter (lambda/R(c))(2) (R(c) is the characteristic size of the cluster). This phenomenon, in contrast to superradiance, leads to an increased [by the factor (lambda/R(c))(2)] lifetime of the system in the excited state and can be called antisuperradiance. (C) 1995 Optical Society of America