Nozaki Kengo, Shinya Akihiko, Matsuo Shinji, Sato Tomonari, Kuramochi Eiichi, Notomi Masaya
NTT Nanophotonics Center, NTT Corp, 3-1 Morinosato Wakamiya Atsugi, Kanagawa 243-0198, Japan.
Opt Express. 2013 May 20;21(10):11877-88. doi: 10.1364/OE.21.011877.
We experimentally and theoretically clarified that a Fano resonant system based on a coupled optical cavity has better performance when used as an all-optical switch than a single cavity in terms of switching energy, contrast, and operation bandwidth. We successfully fabricated a Fano system consisting of doubly coupled photonic-crystal (PhC) nanocavities, and demonstrated all-optical switching for the first time. A steep asymmetric transmission spectrum was clearly observed, thereby enabling a low-energy and high-contrast switching operation. We achieved the switching with a pump energy of a few fJ, a contrast of more than 10 dB, and an 18 ps switching time window. These levels of performance are actually better than those for Lorentzian resonance in a single cavity. We also theoretically investigated the achievable performance in a well-designed Fano system, which suggested a high contrast for the switching of more than 20 dB in a fJ energy regime.
我们通过实验和理论证明，基于耦合光学腔的法诺共振系统在用作全光开关时，在开关能量、对比度和操作带宽方面比单腔具有更好的性能。我们成功制造了一个由双耦合光子晶体（PhC）纳米腔组成的法诺系统，并首次展示了全光开关。清晰地观察到了陡峭的不对称传输光谱，从而实现了低能量和高对比度的开关操作。我们以几飞焦的泵浦能量、超过10分贝的对比度和18皮秒的开关时间窗口实现了开关。这些性能水平实际上优于单腔中的洛伦兹共振。我们还从理论上研究了精心设计的法诺系统中可实现的性能，这表明在飞焦能量范围内开关对比度可超过20分贝。
