POLARITON DISPERSION OF NANOCOMPOSITE BASED PIEZOELECTRIC CRYSTAL

Abstract

The dispersion relation and propagation of phonon-polariton modes in Al doped BaTiO3metal nano composite system is studied by using Maxwell-Garnett approximation. The calculation of dispersion relation shows that four modes of propagation exist. By varying the filling factor, the propagation modes are analysed. It is found that the frequency of the top most mode decreases with the filling factor of the system. The interfacial mode in the polariton dispersion represents the transverse optical phonon frequency of BaTiO3. The dispersion moves towards the higher wave vector region with concentration of metal nanoparticles. This tuning of polaritonic gap is used for various optical applications.