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

Abstract

A lithium–niobate periodic dielectric waveguide modulator design is reported with length as short as 87.4 μm, modulation bandwidth over 600 GHz, voltage‐length product of 0.0874 V cm, and sideband suppression ratio up to 36.1 dB herein. This design provides a compact solution to next‐generation communications and microwave photonics. 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 μm, 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.