Optimization of a Broadband Lithium Niobate-Barium Titanate Hybrid Modulator With Low Half-Wave-Voltage-Length Product

Abstract

The Electro-optic (EO) modulator is one of the most important devices for optical communication. Lithium niobate on insulator (LNOI) platform has matured over the last few years and has resulted in some excellent EO modulators with very low voltages, low optical losses, and high bandwidth. In this paper, we proposed a novel EO modulator based on the LNOI platform where a cladding material of very high dielectric constant i.e., barium titanate (BTO) is used around an etched lithium niobate (LN) waveguide. Lumerical Mode and Device simulations have been used to optimize a Mach-Zehnder interferometer (MZI) based EO modulator that shows a half-wave-voltage-length product as low as $\sim$1.36 V.cm maintaining the optical loss due to metal absorption of $\sim$1 dB/cm. The 3 dB EO bandwidth of $\sim$132 GHz has been estimated using the data generated by the microwave simulations carried out in CST Studio Suite.

Keywords

• High-K dielectric
• lithium niobate modulator
• half-wave-voltage-length product
• broadband modulator