A comprehensive review of optical wireless power transfer technology

Ground-breaking optical wireless power transfer (OWPT) techniques have gained significant attention from both academia and industry in recent decades. Powering remote systems through laser diodes (LDs) to either operate devices or recharge batteries offers several benefits. Remote LDs can remove the burden of carrying extra batteries and can reduce mission time by removing battery swap-time and charging. Apart from its appealing benefits, laser power transfer (LPT) is still a challenging task due to its low transfer efficiency. In this paper, we discuss the necessity and feasibility of OWPT and discuss several projects, working principle, system design, and components. In addition, we show that OWPT is an essential element to supply power to Internet-of-Things (IoT) terminals. We also highlight the impacts of dynamic OWPT. We outline several OWPT techniques including optical beamforming, distributed laser charging (DLC), adaptive-DLC (ADLC), simultaneous lightwave information and power transfer (SLIPT), Thing-to-Thing (T2T) OWPT, and high intensity laser power beaming (HILPB). We also deal with laser selection, hazard analysis, and received photovoltaic (PV) cell selection for OWPT systems. Finally, we discuss a range of open challenges and counter measures. We believe that this review will be helpful in integrating research and eliminating technical uncertainties, thereby promoting progress and innovation in the development of OWPT technologies.