DILAS and USST at the 2007 Space Elevator Games

As has been mentioned in this blog (and elsewhere, I’m sure), DILAS supplied the laser the USST team used in their near-prize-winning run at the 2007 Space Elevator Games.

In this article in the online publication Laser Focus World, DILAS (Tucson) General Manager & Vice-President Dr. Georg Treusch discusses this application from the vendor’s viewpoint.  It’s a somewhat technical and very interesting article.  We learn, for example, that DILAS “…supplied the best performer in 2007 with a power-beaming source on very short notice (three weeks), using a new modular diode-laser-based power beamer that is applicable for both terrestrial as well as spaceborne applications.”  The ‘best performer’ referred to was USST.

Dr. Treusch also discusses what is planned for 2008:

The new design for the power beamer considers various approaches from different teams using low-cost Si- or highly advanced GaAs-based photovoltaic (PV) cells. Material choices, PV cell, and beam characteristics are up to the competing teams; the challenge simply sets the distance and minimum average rate of climb. Each team is likely to have its own approach with power-beaming systems ranging from 2.5 kW to values above 10 kW.

The wavelength for the power-beaming sources will likely be between 800 and 980 nm. High-power diode lasers have efficiencies greater than 60% and power levels greater than 100 W per 10 mm bar. It is a happy coincidence that Si and GaAs photocells are more efficient at this spectral range compared to wavelengths above 1 µm, which is the spectral domain of fiber and disk lasers.

A very interesting article – highly recommended.

Also, while searching through this publication’s archives, I found this article.  While it focuses on delivering power to photovoltaic cells via fiber-optics, it also discusses delivering power to photovoltaics via ‘free space’; i.e. using light (or lasers).  It also briefly mentions the 2005 Space Elevator competition.

I guess I’ll have to keep watch on this publication, too.  So many articles, so little time…