RESUMO
Lithium niobate (LN)-based modulators offer superior modulation performances, including high-speed modulation, linearity, and temperature stability. However, these devices exhibit larger sizes due to the low light-matter interaction despite a significant electro-optic coefficient. In this work, we present a compact LN-based modulator using a plasmonic mode that confines the optical mode in a very narrow gap. By filling the gap with LN, the confinement factor in the LN is significantly enhanced. The proposed modulator provides an extremely small half-wave voltage-length product, VπL of 0.02â V/cm at an optical communication wavelength (λ = 1.55â µm). The proposed modulator scheme can be utilized in a wide range of optical communication devices that demand small footprints and a high-speed operation.
RESUMO
We present a novel, electromagnetically induced transparency system based on guided-mode resonances and numerically demonstrate its transmission characteristics through finite-difference time-domain simulations. The system is composed of two planar dielectric waveguides and a subwavelength grating. It is shown that by coupling the two resonant guide modes with a low- and high-quality factor, a narrow transparency window is generated inside a broad background transmission dip produced by the guided-mode resonance. Our work could provide another efficient way toward the realization of electromagnetically induced transparency.