Micro unmanned aerial vehicle, mostly powered by electricity, plays an important role in many military and civil
applications, e.g. military detection, communication relay et al. But restricted endurance ability severely limits its
applications. To solve the problem, laser wireless power transmission system is proposed. However, overall efficiency of
the system is quite low. This paper describes basic structure of laser wireless power transmission system and its working
process. The system consists of two major modules: a high power laser source transmitting energy and a photovoltaic
receiver converting optical energy into electricity. Then factors influencing efficiency of the system are analyzed. It
suggests that electro-optical efficiency of laser, atmospheric impact on laser beam and photo-electric efficiency of
photovoltaic receiver play significant role in overall efficiency of the system. Atmospheric impact on laser beam mostly
derived from refraction, absorption, scattering and turbulence effects, leads to drop in energy and quality of laser beam.
Efficiency of photovoltaic receiver is affected by photovoltaic materials. In addition, matching degree between intensity
distribution of laser beam and layout of photovoltaic receiver also obviously influence efficiency of photovoltaic receiver.
Experiment results suggest that under non-uniform laser beam illumination, efficiency of photovoltaic receiver mostly
depends on layout of photovoltaic receiver. Through optimizing the layout of photovoltaic receiver based on intensity
distribution of laser beam, output power is significantly improved. The analysis may help to take corresponding measures
to alleviate negative effects of these factors and improve performance of laser wireless power transmission system.