Effects of Receiver-Side Beam Homogenization and Atmospheric Disturbance Mitigation on 1 Km Optical Wireless Power Transmission

Laser-based Optical Wireless Power Transmission (OWPT) enables highly directional long-distance energy delivery. However, atmospheric turbulence near the ground significantly degrades transmission efficiency, particularly during daytime when beam scintillation becomes more severe. In this study, a diffractive optical element (DOE) was employed at the transmitter for beam shaping, while receiver-side disturbance mitigation was achieved using a transmissive diffuser-based homogenizer, a reflector-based optical confinement structure, and a bypass-capacitor-based smoothing circuit. Photovoltaic (PV) cells fabricated by laser cutting commercially available crystalline silicon solar cells were connected in series to construct a 600 mm × 600 mm PV panel. Without receiver-side disturbance mitigation, the output power decreased by more than 50% as the atmospheric structure constant (Cn2) increased from 10−14 to 10−13 m−2⁄3. In contrast, the proposed receiver-side techniques effectively suppressed turbulence-induced performance degradation and maintained nearly constant output power. Furthermore, the combination of the homogenizer and the smoothing circuit increased the receiver output power by approximately a factor of 2.2 under a turbulence condition of Cn2 ≈ 3 × 10−14 m−2⁄3. Using these techniques, 150 W of electrical power was generated over a 1 km outdoor optical link with a 1035 W, 1070 nm near-infrared laser. These results demonstrate that receiver-side disturbance mitigation is an effective approach for improving the efficiency and stability of practical long-distance OWPT systems.