| Mecron |
2012-03-01 10:50 |
国内教材翻译的不对，群速度可以超光速。你可以参考Claus Klingshirn的Semiconductor Optics,3rd Ed第98页最后一段： Ej)7[
For a discussion of the fact, that both the phase- and group velocities can exceed for some frequenciyes the vacuum speed of light. It should be noted, however, that the signal and energy transport velocities never exceed c. `Kg!aN
老一辈中英语不好真是害死后代啊！
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