Improving Linewidth and Extinction Ratio Performances of Lithium Niobate Ring Modulator Using Ring‐Pair Structure

Electro-optic modulators lie at the heart of complex integration and high-density electro-optic systems. One representative is thin-film lithium niobate-based microring modulator which has demonstrated advantages compact footprint, low optical loss, high modulation efficiency. However, linewidth extinction ratio ring are fundamentally limited by losses coupling, respectively. To this end, a novel type with ring-pair structure on niobate platform proposed, brings substantial improvement ratio. The exhibits larger up to 22 GHz, 1.74 times than that single-ring resonator same design parameters. Moreover, experimental results also reveal added-up goes beyond 30 dB, much in an individual resonator. These pave new way for application ring-based large working wavelength window ratio, be exploited quantum optics, programmable nanophotonics sensors, etc.