Low (Sub-1-Volt) Halfwave Voltage Polymeric Electro-optic Modulators Achieved by Controlling Chromophore Shape

TLDR

Electro‑optic modulators encode electrical signals onto fiber‑optic transmissions, but high drive voltages limit performance; typical polymeric and lithium‑niobate devices require ~5 V half‑wave voltages, and sterically modified chromophores have been used to mitigate field‑poling attenuation caused by strong intermolecular electrostatic interactions. The authors employed optical push‑pull poling and driving to lower the half‑wave voltage of polymeric EO modulators. The study fabricated polymeric EO modulators with 0.8‑V half‑wave voltage and a 2.2 V·cm interaction‑length product, and, alongside demonstrations of >110 GHz bandwidth and seamless integration with large‑scale semiconductor and ultra‑low‑loss optical circuitry, shows polymeric materials’ promise for next‑generation telecommunications, information processing, and RF distribution.

Abstract

Electro-optic (EO) modulators encode electrical signals onto fiber optic transmissions. High drive voltages limit gain and noise levels. Typical polymeric and lithium niobate modulators operate with halfwave voltages of 5 volts. Sterically modified organic chromophores have been used to reduce the attenuation of electric field poling-induced electro-optic activity caused by strong intermolecular electrostatic interactions. Such modified chromophores, incorporated into polymer hosts, were used to fabricate EO modulators with halfwave voltages of 0.8 volts (at a telecommunications wavelength of 1318 nanometers) and to achieve a halfwave voltage-interaction length product of 2.2 volt-centimeters. Optical push-pull poling and driving were also used to reduce halfwave voltage. This study, together with recent demonstrations of exceptional bandwidths (more than 110 gigahertz) and ease of integration (with very large scale integration semiconductor circuitry and ultra-low-loss passive optical circuitry) demonstrates the potential of polymeric materials for next generation telecommunications, information processing, and radio frequency distribution.