Broadband Diffractive Solar Sail

TL;DR

This paper compares the transverse radiation pressure force and acceleration of two optimized diffractive solar sail designs, demonstrating that low-refractive-index metasurfaces outperform traditional materials in solar radiation propulsion.

Contribution

It introduces and compares two parametrically optimized diffractive metasurface designs for solar sails, highlighting the superior performance of low-refractive-index materials.

Findings

Low-index metasurface gratings outperform Si3N4 designs.

Optimized low-index metasurfaces achieve higher transverse acceleration.

Numerical results validated by Maxwell stress tensor and modal analysis.

Abstract

The transverse radiation pressure force and acceleration is compared for two parametrically optimized designs: prismatic and two-pillar metasurface gratings. The numerical results were cross-verified with both Maxwell stress tensor and modal analysis. Solar blackbody irradiance was assumed for wavelengths ranging from 0.33 [um] to the grating cutoff at 1.5 [um], encompassing 83% of the solar constant. This multi-objective optimizer study found that neither design comprised Si3N4 performed as well as those corresponding to a low refractive index, low mass density material. The predicted transverse acceleration of the optimized low-index metasurface grating is compared to that of a state-of-the-art reflective solar sail.