Power Beaming with Diode Lasers- Koenning Power Beaming with Diode Lasers

Improvements in the electro optical efficiency and output power of diode lasers within the last few years have made the diode laser a viable source for power beaming. Combined with a growing market of photo voltaics, the key components for power beaming applications have evolved from scientific laboratory experiments into equipment ready for deployment into the field. The NASA sponsored Space Elevator competition is not the only, but maybe the most popular, current application for power beaming. International teams meet once a year to compete using a self designed climber on a rope, while the energy has to be supplied by power beaming from the ground. Starting with a height of 50m in 2005, the goals are increased every year to achieve a required climbing height of 1km for the 2008 contest. The first two contests (2005, 2006) were dominated by spot lights and mirrors reflecting sun light. The first lasers were introduced to the competition in 2007 where the winning team, as well as others, used industrial grade diode lasers as their power source for the 100m lift. The required height of 1km for the 2008 competition requires a sophisticated optical setup to achieve the required spot size at both the minimum and the maximum distance of the climber from the ground. The most important criteria a power beamer is judged by is the overall efficiency. The overall efficiency is determined by the electro-optical efficiency of the source, the opto-electrical efficiency of th