Abstract

Exciton is an elementary excitation coherent over whole the crystal so that it has a macroscopic transition dipolemoment. It, however, behaves almost as a harmonic oscillator and cannot show any optical nonlinearity in itself. Furthermore, the exciton in the bulk crystal has translational symmetry and interacts with radiation field with the same wave vector, resulting in the hybridized modes of the exciton and the light, i.e., the polaritons.

© 1988 Optical Society of America