Jordin T. Kare

Laser Power Beaming On A Shoestring

The NASA Centennial Challenge for Power Beaming is a prize offered for a competitive demonstration of wireless power transmission. The minimum viable competition entry for 2007 was required to deliver greater than 200 watts to a moving 10‐kilogram vehicle over a vertical distance of 100 meters. We describe the design, construction, and operation of a laser power transmission system which considerably exceeds these minimum requirements, and which was built by a largely non‐professional team with minimal financial support in less than one year. The system uses commercially‐available 808 nm diode arrays and simple optics to produce a multikilowatt beam, approximately 1×0.6 m. An automated video tracking system with manual backup and a 1 m2 steerable mirror direct the beam. The receiver is assembled from two types of GaAs photovoltaic cells in a unique configuration. Overall, the system could deliver in excess of 1 kW of DC power to a vehicle with an end to end efficiency of well over 10%, but due to inadequa...