Design of Ultracompact High-Speed-Integrated Lithium-Niobate Periodic Dielectric Waveguide Modulator

Modern communications and microwave photonics require compact electro-optic modulators with ultrahigh bandwidth and low power consumption. These requirements can be satisfied by integrated lithium-niobate electro-optic modulators with high bandwidth and low power consumption. However, most integrated lithium-niobate modulators cannot achieve a good balance between an ultracompact size and a high modulation bandwidth. These challenges are overcome by designing an integrated lithium-niobate periodic dielectric waveguide modulator, featuring a compact modulation length of 87.4 mu m, a theoretical modulation bandwidth over 600 GHz, a voltage-length product of 0.0874 V cm, and a high sideband suppression ratio up to 36.1 dB. These performances are achieved by taking advantage of a capacitor configuration consisting of a nonresonant periodic dielectric waveguides sandwiched between two indium tin oxide (ITO) electrodes. This design provides an ultrabroadband and compact solution to next-generation communications and microwave photonics.