Phonon-Polariton Dispersion Relation of SrTi(¹⁸O_x¹⁶O_1-x)₃

Abstract

The observation of A₁-symmetry phonon-polariton of SrTi(¹⁸O_x ¹⁶O_1-x)₃ was carried out by impulsive stimulated Raman scattering with optical heterodyne detection. By the fit of the phonon-polariton dispersion relation, the static dielectric constant along the polar axis and the soft mode frequency were obtained at once. The present results well associated the previous Raman scattering and dielectric measurement study each other.

Keywords:

• Optical heterodyne detection
• impulsive stimulated Raman scattering
• optical phase mask
• strontium titanate
• ferroelectric phase transition
• soft mode
• isotope exchange

Acknowledgments

The authors appreciate for Professor K. A. Nelson to produce the optical phase masks and many useful suggestions about heterodyne detection. The present study has been supported partially by the Grant-in-Aid for Scientific Research (A) and (B) from Japan Society for the Promotion of Science, No. 1420429 and No. 10044050, respectively, and by U. S. NSF Grants No. DMR-9710140 and INT-9418058.