A new bandwidth-voltage trade-off paradigm in low-loss LNOI electro-optic modulators, using equalizer configuration

Abstract

As a crucial element for various applications, including optical communications and analog photonic links, electro-optic modulators have a small size, low voltage, and wide bandwidth. Electro-optic modulators based on the thin-film lithium niobate (TFLN) are highly efficient and have a large modulation bandwidth. However, there is a tradeoff between driving voltage and modulation bandwidth. In this study, we present the electro-optical modulator based on the TFLN platform by using the electro-optic equalizer. Using the electro-optic equalizer causes that the proposed modulator has a broad bandwidth while the driving voltage is not compromised. In this proposed modulator, to compensate for the velocity mismatch and minimize interference of the electrode with the waveguide, a two-layer metallization method is used. This proposed modulator results in minimal optical and microwave losses and allows for a large electro-optic bandwidth of up to 300GHz for a 5 mm-long device. Additionally, an efficiency of 4.5 V.cm.