Diffraction and Scattering Modeling for Laser Power Beaming in Lunar Environment

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.