Fig. 1. Classification of current wireless power transfer technologies.

Fig. 2. General block diagram of the OWPT.

Fig. 3. Block diagram and picture of the experimental setup.

Fig. 4. E/O conversion efficiency and optical output power of (a) a 200 mW LD and (b) a 500 mW LD.

Fig. 5. Voltage-current graphs of the (a) PV cell and (b) PD by changing the load resistance when the 200 mW LD is operating at the maximum E/O conversion condition.

Fig. 6. Voltage-current graphs of the (a) PV cell and (b) PD by changing the load resistance when the 500 mW LD is operating at the maximum E/O conversion condition.

Fig. 7. E/O conversion efficiency of the LD, the O/E conversion efficiency of the optical power receiver, and the total OWPT efficiency as functions of the optical output power of the LD for the following OWPT systems: (a) 200 mW LD and PV cell, (b) 200 mW LD and PD, (c) 500 mW LD and PV cell, and (d) 500 mW LD and PD. The point marked by the arrow in each figure is the point where the E/O conversion efficiency of the LD is the maximum.