ソフトモードスペクトロスコピーの近況

抄録

This paper reviews the recent developments of spectroscopy techniques as well as the recent observations of new types of soft modes. Instrumentations for measurements of infrared reflectivity, Raman scattering, hyper-Raman scattering and Brillouin scattering are summarized. The new type phase transitions, such as ferroelastic, staggered and incommensurate phase transitions are introduced. Finally future problems on softmode spectroscopy are discussed.