National Science Foundation Nanoscale Science and Engineering Center, 3112 Etcheverry Hall, University of California, Berkeley, CA 94720, USA.
Proc Natl Acad Sci U S A. 2011 Jul 12;108(28):11327-31. doi: 10.1073/pnas.1104418108. Epub 2011 Jun 27.
Miniaturization of optical cavities has numerous advantages for enhancing light-matter interaction in quantum optical devices, low-threshold lasers with minimal power consumption, and efficient integration of optoelectronic devices at large scale. However, the realization of a truly nanometer-scale optical cavity is hindered by the diffraction limit of the nature materials. In addition, the scaling of the photon life time with the cavity size significantly reduces the quality factor of small cavities. Here we theoretically present an approach to achieve ultrasmall optical cavities using indefinite medium with hyperbolic dispersion, which allows propagation of electromagnetic waves with wave vectors much larger than those in vacuum enabling extremely small 3D cavity down to (λ/20)(3). These cavities exhibit size-independent resonance frequencies and anomalous scaling of quality factors in contrast to the conventional cavities, resulting in nanocavities with both high Q/V(m) ratio and broad bandwidth.
光学腔的小型化在增强量子光学器件中的光物质相互作用、低阈值、最小功耗的激光器以及大规模集成光电设备方面具有诸多优势。然而，由于自然材料的衍射极限，真正纳米级光学腔的实现受到了阻碍。此外，随着腔尺寸的缩小，光子寿命会显著降低，从而降低小腔的品质因数。在这里，我们从理论上提出了一种使用具有双曲色散的不定形介质来实现超小光学腔的方法，这种方法可以传播波矢远大于真空中的电磁波，从而能够实现极其微小的 3D 腔，尺寸小至(λ/20)(3)。与传统腔相比，这些腔表现出与尺寸无关的共振频率和反常的品质因数缩放，从而得到具有高 Q/V(m)比和宽带宽的纳米腔。
