Spatiotemporal refraction of light in an epsilon-near-zero indium tin oxide layer: frequency shifting effects arising from interfaces
Spatiotemporal refraction of light in an epsilon-near-zero indium tin oxide layer: frequency shifting effects arising from interfaces
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DOI：
10.1364/optica.436324
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发表时间：
2021-12-20
期刊：
影响因子：
10.4
通讯作者：
Hendry, Euan
中科院分区：
文献类型：
--
作者：
Bohn, Justus;Luk, Ting Shan;Hendry, Euan
当光穿过折射率随时间快速变化的介质时，光的频率将发生变化。最近报道了透明导电氧化物的显着频移效应。这些观察结果被解释为由于折射率的时间变化而导致体介质中传播相位的时间变化。这是一种称为时间折射的效应。在这里，我们表明，由氧化铟锡制成的ε近零层中的频移不仅源于这种体响应，而且还包括由于空间边界条件的时间变化而产生的显着影响。对于某些角度，这种边界效应可能会导致主体效应发生显着的、相反的变化。因此，这个过程会产生可以通过角度定制的频移，从而解耦幅度和相位调制。由光学协会根据知识共享署名 4.0 许可条款发布。
When light travels through a medium in which the refractive index is rapidly changing with time, the light will undergo a shift in its frequency. Significant frequency shifting effects have recently been reported for transparent conductive oxides. These observations have been interpreted as emerging from temporal changes to the propagation phase in a bulk medium resulting from temporal variations in the refractive index. It is an effect referred to as temporal refraction. Here, we show that the frequency shift in an epsilon-near-zero layer made of indium tin oxide originates not only from this bulk response but includes a significant effect resulting from temporal changes to the spatial boundary conditions. This boundary effect can lead to a dominant, opposing shift to the bulk effect for certain angles. Hence, this process gives rise to a frequency shift that can be tailored through the angle, decoupling the amplitude and phase modulation. Published by The Optical Society under the terms of the Creative Commons Attribution 4.0 License.