Highly Efficient Slow-Light Mach–Zehnder Modulator Achieving 0.21 V cm Efficiency with Bandwidth Surpassing 110 GHz (Laser Photonics Rev. 19(8)/2025)

Integrated Slow-Light Mach–Zehnder Electro-Optic Modulator

High-speed electro-optic modulators are key components in modern communication networks and various applications that require chip-scale modulation with large bandwidth, high modulation efficiency, and a compact footprint. In article number 2401092, Yong Zhang, Yikai Su and co-workers demonstrate a Mach–Zehnder electro-optic modulator that harnesses slow-light waveguides and capacitively loaded slow-wave electrodes on silicon-nitride-loaded lithium niobate on an insulator platform. By employing slow light in the topological waveguides and low-loss slow-wave electrodes, the modulation efficiency can be improved. Meanwhile, the good electro-optic velocity and impedance matching by the segmented slow-wave electrodes enable a superior electro-optic bandwidth. The modulator provides ultra-large bandwidth, ultra-high efficiency, and a compact solution for next-generation electro-optic systems.