Laser Power Transmission Employing a Dual-Use Photovoltaic Concentrator at the Receiving End

The proposed innovation is a wireless laser power transmission system employing a dual-use photovoltaic concentrator at the receiving end. Specifically, the laser receiver/converter employs thin stretched-membrane Fresnel lenses to focus continuous or pulsed laser light onto small photovoltaic cells, thereby reducing cell cost and improving cell conversion efficiency. The dual-use approach can be implemented in several ways, to allow the same photovoltaic concentrator array to be used as a solar array and/or a laser receiver/converter array. Specifically, the photovoltaic concentrator employs multi-junction cells for high-efficiency solar radiation conversion, and single-junction cells for the high-efficiency laser radiation conversion. A prototype lens/cell unit was successfully tested in Phase I, and a more optimal array will be built and tested in Phase II. The new modular laser/solar photovoltaic concentrator will have many NASA, military, and commercial space applications. Applications include spacecraft arrays receiving laser input from other spacecraft or from Earth; lunar or planetary arrays receiving laser input from nearby spacecraft or from Earth; and Earth-based arrays receiving laser input from space solar power (SSP) spacecraft. The dual-use capability enables state-of-the-art solar operation when sunlight is available (e.g., illuminated orbit portion), and laser operation when sunlight is not available (e.g., eclipse orbit portion).