Abstract

Spatial dispersion effect has been one of the most important problems in exciton optics since Pekar pointed out the existence of the anomalous waves in 1957. Because this effect always appears in the highly absorbing region of exciton resonance, it is not easy to study this effect with the ordinary spectroscopy. Recently we have developed the two-photon polarization spectroscopy (TPPS), which is based on the photo-induced optical anisotropy coming from the renormalization of exciton polaritons (EP's) due to the two-photon formation of excitonic molecules (EM's). By this method we can monitor the number of EP's in the spatially dispersive region through the change in the polarization of the probe light with the energy in the transparent region. Here we will demonstrate how the TPPS displays its effectiveness to study the spatial dispersion effect of the EP's in CuCl and show the various features of EP's revealed by this method.

© 1984 Optical Society of America