Optical Wireless Power Transmission Using a GaInP Power Converter Cell under High-Power 635 nm Laser Irradiation of 53.5 W/cm2

Abstract

Optical wireless power transmission (OWPT) system is a technology that supplies energy from remote locations, having some features such as long-distance transmission, high directivity, and no electromagnetic noise interference. This study investigated the optical transmission efficiency and photoelectric conversion efficiency with a transmission distance of 10 m using GaInP power converter cells with a small area of 2.40 × 2.40 mm2 and a 635 nm high-power laser over 50 W/cm2. As a result, we achieved a photoelectric conversion efficiency of 44.7% under 6.7 W/cm2 (0.14 W) and 37.2% under 53.5 W/cm2 (1.1 W) irradiation. These results suggested that W-class optical wireless power transmission could be realized by expanding the converter cell area. Additionally, it was found that the reductions of the divergence angle of the laser and the heat generation of the power converter cell were critical issues for further lengthening the distance and increasing the power.