A photoactive moiety exhibiting an anisotropic transition dipole. The moiety
exhibits
emission of polarized light in response to energy absorption. In a preferred embodiment,
the moiety comprises a particle from the group consisting of a crystalline arrangement
of photoactive molecules and a photoactive nanocrystal. The moiety may include
a matrix in which photoactive objects exhibiting an anisotropic emission dipole
are embedded. The moiety may be photobleached to product the anisotropy and the
photoactive objects may have a one dimensional transition dipole in their natural state.