Control of materials by coherent phonon excitation

Coherent phonon is created by the optical excitation using a ultrashort pulse whose duration isshorter than the period of the phonon vibration. If the single excitation pulse is replaced by thepulse train where the pulse separation is equal to the period of the phonon vibrationthe amplitude of the coherent phonon increases drastically.使用the pulse-train excitation we weretrying to control of the phase of materials.我们的研究成果是遵循；1 .我们建立了一个系统，用于实验的创建和coherent phonon measurement .Using a Bi material，我们确认我们的系统工作良好，and observed the amplification of coherent phonon with a pulse-train excitation.2) We studied theproperties of the coherent phonon in the exciton resonance region of a layered semiconductorPbI D22 d2.3) We studied the excitonic nonlinearity and the interaction between the exciton andthe coherent phonon in a self-organized quantum-well material（C - D26 D2H D213 D2NH D23 D23 D2） C - D22 D2PbI D24 d2.4 We studied the interaction between theexciton and the coherent phonon in a π-混合polymer polythiophene。

Coherent phonon is created by the optical excitation using a ultrashort pulse whose duration is shorter than the period of the phonon vibration. If the single excitation pulse is replaced by the pulse train where the pulse separation is equal to the period of the phonon vibration, the amplitude of the coherent phonon increases drastically. Using the pulse-train excitation we were trying to control of the phase of materials. Our research results are following ;1) We set up the system for the experiments of the creation and measurement of coherent phonon. Using a Bi material, we confirmed that our system worked well, and observed the amplification of coherent phonon with a pulse-train excitation.2) We studied the properties of the coherent phonon in the exciton resonance region of a layered semiconductor PbIィイD22ィエD2.3) We studied the excitonic nonlinearity and the interaction between the exciton and the coherent phonon in a self-organized quantum-well material (CィイD26ィエD2HィイD213ィエD2NHィイD23ィエD2)ィイD22ィエD2PbIィイD24ィエD2.4) We studied the interaction between the exciton and the coherent phonon in a π-conjugated polymer polythiophene.