负波速研究进展  

Recent Advances in Negative Wave Velocity Research

作　　者：黄志洵[1] 

机构地区：[1]中国传媒大学信息工程学院,北京100024

出　　处：《前沿科学》2012年第4期46-66,共21页Frontier Science

摘　　要：近年来有众多实验证明了超过真空中光速的可能性,并从理论上和实验上对群速超光速和负群速作了研究。本文着重论述负波速的光传播,例如光脉冲通过被测物(如原子气室或光纤)时其峰值在进入它之前就在它的输出端出现了,从而呈现出负渡越时间和负群速(NGV)。可以证明当Goos-Hnchen位移GHS为负,即D<0,而|D|>dΦ/dkz,则可获得负渡越时间(τ<0)。……文中论述的NGV传播是依靠反常色散媒质或消失波而实现的。在电磁理论中相速、群速可定义为矢量或标量。如在标量表达时出现负号,例如νg=-c/ng,不能认为负号只表示向反方向传播。必须指出在Sommerfeld-Brillouin波速理论中负群速是超光速的一种形态。本文提出了开展"三负研究"的思想,所谓"三负"是指负折射、负波速和负GH位移。如果我们透过现象看本质,这三方面的内在联系是非常重要的。最后,本文深入讨论了量子波动的内容和意义。Recently, many experiment have demonstrated the possibility to exceed the velocity of light in vacuum, superluminal or negative wave velocity propagation has been studied in theory and experiments. In this paper, we report the demonstration of light propagation at negativc wave velocity. For example, a light pulse propagating through the DUT（such as a atomic vapor cell or an optical fiber） has its peak reaching the exit side before entering it, resulting in a negative transit time, and negative group velocity（NGV）. It can be seen when the GHS is negative（D〈0）, but ｜ D｜〉dФ/dk_c ,we can obtain the negative transit time（ τ〈0）.…… Then we report superluminal propagation or NGV propagation are arc the state of anomalous dispersion media or evanescent waves. In EM theory, the phase velocity and group velocity are defined as vector or scalar. If the negative sign appears in scalar form, such as v_g --c/n_g, it can＇t be only understood as the ncgative sign means the negative direction propagation. Moreover For the Sommerfeld-Brillouin wave theory, it is accepted that the negative group velocity is Faster than the light speedc＇. Then, we report on our investigations of study on the three negative parameters, i.e. the negative refraction index, negative wave velocity and negative GHS. When we see the essence through the phenomena, the internal connections of these three things are very important. Finally, we profoundly discuss the substance and meaning of quantum waves.

关 键 词：负群速 负时延 反常色散 消失态 负折射 负GH位移 量子波动 

分 类 号：O43[机械工程—光学工程]