Plasmon-induced transparency based on aperture-coupled cascade resonators without gap

We numerically and theoretically investigate a metal-insulator-metal (MIM) system based on aperture-coupled cascade resonators without gap to achieve plasmon-induced transparency (PIT). Such structure not only can be fabricated easily, but also possesses low intrinsic loss. Consequently, a high transmitted PIT peak more than 90% can be achieved, and this device also has good performance on sensing and slow light. Finally, multi-channel PIT and slow light can be achieved via cascade multiple resonators. This work provides a valuable approach to realize on-chip PIT in practical experiments.