Arkhipov M V, Arkhipov R M, Pakhomov A V, Babushkin I V, Demircan A, Morgner U, Rosanov N N
Opt Lett. 2017 Jun 1;42(11):2189-2192. doi: 10.1364/OL.42.002189.
We propose a strikingly simple method to form approximately unipolar half-cycle optical pulses via reflection of a single-cycle optical pulse from a thin flat metallic or dielectric layer. Unipolar pulses in reflection arise due to specifics of one-dimensional pulse propagation. Namely, we show that the field emitted by the layer is proportional to the velocity of the oscillating charges in the medium, instead of their acceleration. Besides, the oscillation velocity of the charges can be forced to keep a constant sign throughout the pulse duration. That is, reflection of ultrashort pulses from broad-area layers with nanometer-scale thickness can be very different from the common reflection in the case of longer pulses and thicker layers. This suggests a possibility of unusual transformations of few-cycle light pulses in completely linear optical systems.
我们提出了一种极其简单的方法，通过单周期光脉冲从薄的扁平金属层或介电层反射来形成近似单极半周期光脉冲。反射中的单极脉冲是由于一维脉冲传播的特性而产生的。具体而言，我们表明该层发射的场与介质中振荡电荷的速度成正比，而不是与它们的加速度成正比。此外，电荷的振荡速度可以在整个脉冲持续时间内被迫保持恒定的符号。也就是说，超短脉冲从纳米级厚度的大面积层的反射可能与较长脉冲和较厚层情况下的普通反射非常不同。这表明在完全线性光学系统中少周期光脉冲可能会发生异常变换。
