Slow-Wave-Enhanced High-Efficiency Electro-Optic Modulator on Thin-Film Lithium Niobate

The increased demand for global usage of cloud data storage, transmission, and processing highlights the need for higher performance optical transceivers. Compact, efficient modulators with wide bandwidths and high extinction ratios must be designed at the component level for application in mid- and long-haul transceivers. This work presents the design of electro-optic modulators on thin-film lithium niobate capable of addressing this burgeoning data requirement. Slow-wave enhancement of the effective modulation length has not yet shown potential for commercialization due to velocity or index mismatch between the optical carrier field and the RF-modulation signal. This work addresses this deficiency by designing slow-wave-matched electrodes and optical waveguides with corrugated gratings to achieve a modulator with a 1.25 V DC half-wave voltage, while maintaining greater than 100 GHz of bandwidth. This result provides the opportunity for seamless integration with complementary metal-oxide-semiconductor electronics without the use of power-hungry RF preamplifiers for mid- and long-haul fiber-optic communications.