PHOTOELECTRIC DOMAIN-STRUCTURE IN RUBY - STUDIES WITH ELECTRIC-FIELD MODULATION OF PHOTON-ECHO

Electric-field-modulated two-pulse photon-echo experiments were perfor med in heavily doped ruby crystals containing photoinduced domains pos sessing internal electric fields. The photon-echo modulation patterns are sensitive to the photoelectric domain structure in the crystals. S tudies as a function of the relative orientation of the optical excita tion beam and the crystal axes make it possible to obtain information about the size and shape of the domains. The domains occur in sheets o riented perpendicular to the c axis and are about 20 mu m in thickness .