Plasmon-induced Transparency Window Research Articles

High-contrast electro-optic modulation of spatial light induced by graphene-integrated Fabry-Pérot microcavity

We have proposed a graphene-integrated Fabry-Pérot microcavity for efficient modulation of spatial light. A simplified theoretical model is established to analyze the performance of our system, and the calculated results agree well with the simulation results. It is shown that the plasmon-induced transparency (PIT) effect is achieved in the proposed microcavity and the central frequency of PIT window can be dynamically tuned by gate voltages. In particular, the PIT spectra exhibit extremely large modulation depths (∼90%) across a broad range of frequencies. The proposed ultracompact configuration demonstrates a type of cavity-induced high-contrast and frequency-selective electro-optic modulators, offering opportunities in exploiting active chip-integrated high-performance devices operating at frequencies from terahertz to mid-infrared.

Power transmission and group delay in gain-assisted plasmon-induced transparency

A gain-assisted plasmonic waveguide with two detuned resonators is investigated in the plasmon-induced transparency window. Phase map is employed to study power transmittance and group delay for varying gain coefficients and frequency detunings of the two resonators. The gain coefficient for lasing oscillation condition is analytically shown to vary quadratically with the frequency detuning. In the amplification regime below the lasing threshold, the spectrum implies not only large group delay, but also high transmittance and narrow linewidth. This is in contrast to those in the loss-compensation regime and the passive case in which there always exists a trade-off between the linewidth and the peak transmittance.