Ardavan Houshang, Ardavan Arzhang, Singleton John
Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK.
J Opt Soc Am A Opt Image Sci Vis. 2003 Nov;20(11):2137-55. doi: 10.1364/josaa.20.002137.
We investigate the spectral features of the emission from a superluminal polarization current whose distribution pattern rotates (with an angular frequency omega) and oscillates (with a frequency omega > omega differing from an integral multiple of omega) at the same time. This type of polarization current is found in recent practical machines designed to investigate superluminal emission. Although all of the processes involved are linear, we find that the broadband emission contains frequencies that are higher than omega by a factor of the order of (omega/omega)2. This generation of frequencies not required for the creation of the source stems from mathematically rigorous consequences of the familiar classical expression for the retarded potential. The results suggest practical applications for superluminal polarization currents as broadband radio-frequency and infrared sources.
我们研究了超光速极化电流发射的光谱特征，该电流的分布模式同时旋转（角频率为ω）和振荡（频率为ω＞ω，且与ω的整数倍不同）。这种极化电流出现在最近设计用于研究超光速发射的实际机器中。尽管所有涉及的过程都是线性的，但我们发现宽带发射包含的频率比ω高(ω/ω)²量级的因子。这种产生源创建不需要的频率源于延迟势熟悉的经典表达式的数学严格结果。这些结果表明超光速极化电流作为宽带射频和红外源的实际应用。
