Transmitter Rotation for Field of View Enhancement in Resonant Beam Wireless Power Transfer

Providing continuous power supply for Internet of Things (IoT) devices such as smartphones, via wireless power transfer (WPT) technology presents significant challenges. Optical WPT, with its high transmission efficiency, is a promising solution. However, maintaining alignment between the transmitter and receiver in optical WPT system typically requires complex tracking control. The resonant beam can be generated inside a spatially separated laser resonator (SSLR) between the transmitter and the receiver without beam steering devices and alignment/tracking process even when the receiver is shifted or deflected. To improve the portability of the receiver, a large field of view (FoV) is necessary for the resonant beam wireless power transfer (RB-WPT) system. However, it is difficult to improve the FoV of the RB-WPT system, which is limited by the complexity of the resonator design. In this paper, we propose an FoV-improved RB-WPT system featuring a rotatable transmitter, which can enhance the system’s transmission efficiency simultaneously. Experimental results demonstrate that the receiver can move freely along a 1.1 m rail positioned 2 m from the transmitter, maintaining a stable received optical power of approximately 0.4 W.