Plansinis B W, Donaldson W R, Agrawal G P
The Institute of Optics, University of Rochester, 275 Hutchison Road, Rochester, New York 14627, USA.
Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA.
Phys Rev Lett. 2015 Oct 30;115(18):183901. doi: 10.1103/PhysRevLett.115.183901. Epub 2015 Oct 28.
It is shown numerically and analytically that when an optical pulse approaches a moving temporal boundary across which the refractive index changes, it undergoes a temporal equivalent of reflection and refraction of optical beams at a spatial boundary. The main difference is that the role of angles is played by changes in the frequency. The frequency dependence of the dispersion of the material in which the pulse is propagating plays a fundamental role in determining the frequency shifts experienced by the reflected and refracted pulses. Our analytic expressions for these frequency shifts allow us to find the condition under which an analog of total internal reflection may occur at the temporal boundary.
数值和分析结果表明，当光脉冲接近折射率发生变化的移动时间边界时，它会经历光束在空间边界处的时间等效反射和折射。主要区别在于，角度的作用由频率变化来体现。脉冲传播所在材料的色散频率依赖性在确定反射和折射脉冲所经历的频率偏移方面起着基本作用。我们针对这些频率偏移的解析表达式使我们能够找到在时间边界处可能发生全内反射类似情况的条件。
