学术讲座通知
演讲人: Chao Zhang, University of Michigan, USA
题目: Introduction on negative reflection and superluminal effects
时间: 2008年6月5日 (周四) 下午4:00~5:30
地点: 东南大学李文正楼614北会议室
主办: 东南大学毫米波国家重点实验室
IEEE AP-MTT-EMC Joint Nanjing Chapter
江苏省电子学会天线与微波专业委员会
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Abstract:
1. Negative Reflection
In chiral medium, two circular polarized eigenmodes are splitted. Without large spatial dispersion, the chirality can be strong enough to make one of the eigenmode backward, i.e. antiparallel wave vector and Poynting vector. In this case, the wave will be reflected negatively on the interface. Hence the partial imaging can be achieved by a plane mirror.
2. Superluminal effects
Both fast light and tunneling can approach superluminality without violation on causality. Fast light occurs around the region where the index changes rapidly with frequency. Quantum tunneling means the probability of a particle transmitting through a finite barrier where the potential is higher than its kinetic energy. Photonic tunneling is acoupling process by evanescent waves. It is found that such tunnelingusesless time thanpropagating through the same distancein vacuum without observable reshaping, andwill saturate quickly with the growth of the barrierwidth. The time delayis not a propagating time, but the lifetime of the evanescent energy storage inside the barrier.
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