科研成果

By coating a metal with a finite-thickness dielectric film, evident differences in the wave-vector magnitude between surface plasmon polaritons (SPPs) and quasicylindrical waves (quasi-CWs) emerge. This brings modulation patterns to the total field on the metal surface near the electromagnetic source. Based on such an effect, an ultracompact SPP splitter with a lateral dimension of only 800 nm is experimentally demonstrated at wavelengths of 740 nm and 832 nm in a dielectric-film-coated asymmetric single nanoslit. These results imply that the additional modulation of quasi-CWs to the total field provide new possibilities for the design of ultracompact plasmonic devices. (C) 2011 American Institute of Physics. [doi:10.1063/1.3564935]

By exciting a plasmonic lens with femtosecond laser and utilizing the optical nonlinearity of the gold, an ultrasmall and ultrafast all-optical modulation spot was achieved inside a thin gold film. Near-field pump-probe measurements indicated a modulation spot size of about 600 nm, and a response time of about 1.5 ps. Even smaller spot size of about 300 nm was inferred from numerical simulations, beyond the diffraction limit given an incident wavelength of 1000 nm. Moreover, the optical nonlinearity and the modulation depth were increased by one order of magnitude at the focus compared to that at positions without structures. (C) 2011 American Institute of Physics. [doi:10.1063/1.3581895]

<正>我们可以用一个全新的、极为开放的网络模型重新思考、重新建立社会的许多行业和部门奥瑞·奥科罗(Ory Okolloh)是肯尼亚一位非常著名的律师和博客作者。2007年肯尼亚争议性的选举之后爆发了严重的暴力事件,她不断地从不同的亲朋好友口中听到令人不安的强奸、抢劫和谋杀事件,开始怀疑政府和官方媒体对这些暴力事件的报告极不充分。她在自己的博客KenyanPundit上记录了一次由于肯尼亚政府禁止主流媒体报道而引发的暴力冲突后,引起了连锁反应,那些亲眼目睹或者亲身经历过暴力事件的人向她发送了大量的邮件和信息,就这样她开始收集证据。大量的报