High-Efficiency, Slow-Light Modulator on Hybrid Thin-Film Lithium Niobate Platform

In this letter, we experimentally demonstrate the first slow-light Mach-Zehnder modulator (MZM) on a hybrid ithin-film Lithium Niobate platform. The Bragg grating waveguides are served as phase shifters, which enhance the modulation efficiency with the slow-light effect. Compared with large-signal modulation efficiency ( $\text{V}_\pi \cdot \text {L} =0.67\,\,\text{V}\cdot $ cm) and an ultra-compact footprint (0.3 mm $\times1.2$ mm). Data transmission up to 60 Gbps and an on-chip insertion loss of 1.9 dB are also achieved. This modulator provides a potential solution for high-intensity integration, low-power transmission, and optical biosensing.