COHERENT PHONON EXCITATION BY ULTRAFAST PULSE TRAINS

摘要：

Time resolved reflectivity of bismuth thin film evaporated on a silicon substrate is measured by an 80 femtosecond (fs) laser at a center wavelength of 800 nm. The reflectivity data reveal that coherent optical phonons (A1g) near 2.9 THz (1 THz = 1012 Hz) are excited by the 80 fs laser pulses. Analyses of the reflectivity data reveal key parameters related to electron and phonon dynamics, including phonon excitation and de-phasing and electron-phonon energy coupling. It is also found that the phonon frequency peaks are red-shifted and broadened at higher laser fluences. We also show that the phonon oscillation can be manipulated by specifically designed ultrafast pulse trains with different pulse separation times.

作者: Alexander Q. Wu Xianfan Xu

作者单位: School of Mechanical Engineering Purdue University West Lafayette,IN

会议类型: 国际会议

会议名称: 2007年微纳系统集成及其商业化应用国际学术会议(2007 International Conference & Exhibition on Integration and Commercialization of Micro and Nano-Systems)

会议地点: 海南三亚

会议语种:英文

在线出版日期: 2007-01-10（万方平台首次上网日期，不代表论文的发表时间）