Diffraction and Scattering Modeling for Laser Power Beaming in Lunar Environment

TL;DR

This paper models how lunar dust affects laser beam propagation for power beaming, revealing significant efficiency losses and highlighting the importance of system elevation and dust characteristics for lunar energy transfer.

Contribution

It introduces a detailed diffraction and scattering simulation model that accounts for non-uniform dust effects, improving upon prior uniform-layer assumptions.

Findings

Dust significantly degrades energy transfer efficiency.

Increasing laser height improves transmission range and efficiency.

Particle size critically impacts beam attenuation and system design.

Abstract

Reliable energy delivery is a critical requirement for long-term lunar missions, particularly in regions with limited solar access, such as polar craters and during extended lunar nights. Optical Power Beaming (OPB) using high-power lasers offers a promising alternative to conventional solar power, but the effects of suspended lunar dust on beam propagation remain poorly understood. This study introduces a detailed simulation model that incorporates both diffraction and height-dependent scattering by the electrostatically suspended lunar regolith. Un like prior approaches, which assumed uniform dust layers or center-to-center transmission loss, our model uses generalized diffraction theory and refractive index gradients derived from particle density to assess beam deformation and attenuation. The results show that even in ground-to-ground scenarios, lunar dust significantly degrades energy transfer efficiency, dropping from 57% to 3.7% over 50 km in dust-free vs. dusty conditions with 175 nm particles. Increasing the particle size to 250 nm limits the viable transmission range to below 30 km at 6% efficiency. The study further demonstrates that raising the laser source height can improve efficiency, achieving 91% for a distance of 5 km and 25% at 50 km when the source is positioned 12 m above ground. These findings underscore the importance of system elevation and dust modeling in lunar OPB design and reveal the mission-critical role of particle size distribution, especially in environments disturbed by human activity.