A reflective millimeter-wave photonic limiter.

Kononchuk, Rodion; Suwunnarat, Suwun; Hilario, Martin S; Baros, Anthony E; Hoff, Brad W; Vasilyev, Vladimir; Vitebskiy, Ilya; Kottos, Tsampikos et al. · Sci Adv · 2022

basic_science · Level V

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Abstract

Millimeter-wave (mm-wave) communications and radar receivers must be protected from high-power signals, which can damage their sensitive components. Many of these systems arguably can be protected by using photonic limiting techniques, in addition to electronic limiting circuits in receiver front-ends. Here we demonstrate, experimentally and numerically, a free-space, reflective mm-wave limiter based on a multilayer structure involving a nanolayer of vanadium dioxide VO<sub>2</sub>, which experiences a heat-related insulator-to-metal phase transition. The multilayer acts as a variable reflector, controlled by the incident wave intensity. At low intensities VO<sub>2</sub> remains dielectric, and the multilayer exhibits strong resonant transmittance. When the incident intensity exceeds a threshold level, the emerging metallic phase renders the multilayer highly reflective while safely dissipating a small portion of the input power, without damage to the limiter. In the case of a Gaussian beam, the limiter has a nearly constant output above the limiting threshold input.