Pentagonal photonic crystal mirrors: scalable lightsails with enhanced acceleration via neural topology optimization.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 40128195.
- Also identified by DOI 10.1038/s41467-025-57749-y and PMC identifier 11933360.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The Starshot Breakthrough Initiative aims to send gram-scale microchip probes to Alpha Centauri within 20 years, propelled by laser-driven lightsails at a fifth of light speed. This mission demands innovative lightsail materials with meter-scale dimensions, nanoscale thickness, and billions of nanoscale holes for enhanced reflectivity and reduced mass. Unlike the microchip payload, lightsail fabrication requires breakthroughs in optics, materials science, and structural engineering. Our study uses neural topology optimization, revealing a novel pentagonal lattice-based photonic crystal (PhC) reflector. The optimized designs significantly lower the acceleration times and, thereby, launch cost. Crucially, they also enabled orders-of-magnitude fabrication cost reduction. We fabricated a 60 × 60 mm<sup>2</sup>, 200 nm thick reflector with over a billion nanoscale features, achieving a 9000-fold cost reduction per m<sup>2</sup>. This represents the highest aspect ratio nanophotonic element to date. While stringent requirements remain for lightsails, scalable, cost-effective nanophotonics present promising solutions for next-generation space exploration.