総説 |
ブリルアン分光の新展開 A New Development in Brillouin Spectroscopy 齊官 清四郎 実時間での光ビート周波数のモニターとFM分光法を取り入れた分解能20 kHz の誘導ブリルアン分光装置を開発した。結晶、ガラスにおける高分解能なブリルアン分光が可能となり、定在波フォノンによるブリルアンスペクトルの分裂、結晶におけるブリルアン線幅とシフトの温度特性、ガラスにおけるTLS(two level systems)の共鳴吸収と緩和の観測に成功した。 Using real-time beat frequency monitor and frequency modulation technique, we have developed a high precision Brillouin spectrometer with the spectral resolution of 20 kHz. This spectrometer has been applied to studies of temperature dependence of Brillouin frequency shift and linewidth for both of crystals and glasses. We have observed a splitting of Brillouin spectrum due to standing wave phonon in crystals and resonant absorption due to two level systems (TLS) in glasses below the liquid He temperature. Keywords:Brillouin scattering, Frequency-modulation spectroscopy, Three-phonon process, Two level systems |
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