Thermally reliable compact electro-optic modulators with a low half-wave voltage

Recent advancements in thin-film lithium niobate have led to the development of high-performance integrated electro-optic modulators, which are crucial for modern optical communication systems. These modulators offer tighter mode confinement, a smaller physical footprint, and reduced modulating voltages. This study presents a Mach-Zehnder modulator (MZM) on a silicon nitride-loaded lithium niobate platform using a few-mode waveguide structure. By harnessing the exceptional thermo-optic and electro-optic effects of LiNbO 3 , we design and simulate this modulator employing multilayer structures with the BeamPROP solver. The modulator has a length of 3.94 mm, a V π value of 0.96 V, and a transition temperature (T g ) of 80 °C at 1.55 µm. This proposed modulator exhibits a crosstalk of approximately -42 dB, an extinction ratio of approximately 24 dB, and a maximum transmission of -28 dB for the first-order phase shift. These findings demonstrate the significant potential of this modulator for deployment in high-speed optical communication systems, where maintaining thermal stability and optimizing energy efficiency are paramount.