A solar-pumped laser is a laser that shares the same optical properties as conventional lasers such as emitting a beam consisting of coherent electromagnetic radiation which can reach high power, but which uses solar radiation for pumping the lasing medium. This type of laser is unique from other types in that it does not require any artificial energy source.
 Lasing media
The two most studied lasing media for solar-pumped lasers have been iodine, with a laser wavelength of 1.31 micrometers, and NdCrYAG, which lases at 1.06 micrometers wavelength. Solar-pumped semiconductor lasers have also been proposed by Landis and others.
Solar-pumped lasers are not used commercially because the low cost of electricity in most locations means that other more efficient types of lasers that run on electrical power can be more economically used. Solar pumped lasers might become useful in off-grid locations.
Very fine grained dispersed powders can be produced by the use of laser synthesis technology .
 Hydrogen production
A leader in this field is Shigeaki Uchida and his team in Japan (Tokyo/Osaka). Their design uses Fresnel lenses and a solar-pumped NdCrYAG laser to drive a magnesium-based cycle, which produces hydrogen gas as its product.
 Potential spacecraft applications
Since there is no "grid power" in space, most spacecraft today use solar power sources, mostly photovoltaic solar cells. Powering lasers requires high levels of power, so the inefficiency of PV solar cells (usually less than 27% efficiency) motivates interest in solar pumping of lasers. Other potential benefits of solar-pumped lasers might be reduced weight and reduced number of components, affording higher reliability (reduced number of failure modes) versus an electrically pumped laser powered from PV cells.
 Space propulsion
There have been proposals to use solar-pumped lasers for spacecraft beam-powered propulsion.
 Solar power satellite
There have been proposals to use solar-pumped lasers for space-based solar power.
 Military applications
There have been proposals to use solar-pumped lasers in space for ballistic missile defense.
 Current research
The largest solar-pumped laser is currently being operated by a research facility in Uzbekistan. It is a 1 MW solar input power NdYAG type laser, operating at 3,000 degrees C. It is cooled by distilled water.
- De Young et al. Preliminary Design and Cost of a 1-Megawatt Solar-Pumped Iodide Laser Space-to-Space Transmission Station, NASA Technical Memorandum, 1987 (Original version, WebCite archive), Retrieved 2011-06-23
- G.A. Landis, "New Approaches for a Solar-Pumped GaAs Laser," Optics Communications, 92, pp 261-265 (1992). (Abstract)
- I.M. Tsidulko, "Semiconductor Laser Pumped by Solar Radiation," Soviet Journal of Quantum Electronics 22 (5), pp. 463-466 (1992).
- Sh. D. Payziyeva; S. A. Bakhramov, and A. K. Kasimov. "Transformation of concentrated sunlight into laser radiation on small parabolic concentrators". Journal of Renewable and Sustainable Energy (Scientific and Production Association “Akadempribor”, Tashkent 100125, Uzbekistan: American Institute of Physics) 3 (5).
- "Can Lasers Help Decrease Our Dependence on Fossil Fuels?". Retrieved 2009-05-05.
- "Solar light pumped laser and cooling method of solar light pumped laser, USPTO Application #: 20080225912". Retrieved 2009-05-05.
- Geoffrey A. Landis, "Prospects for Solar Pumped Semiconductor Lasers," Paper SPIE 2121-09, Laser Power Beaming, SPIE Proceedings Volume 2121, pp. 58-65, January 27–28, 1994 (web version access date 2009-11-10)
- "Physics-sun solar laser oozes millions of watts". Retrieved 2009-05-05.
- "blog post: 1MW Solar Powered Laser Made in Uzbekistan". Retrieved 2009-05-05. (mirrored version): "1MW Solar Powered Laser Made in Uzbekistan". Retrieved 2009-05-05.
- "Uzbek scientists created a powerful solar laser". Retrieved 2009-05-05.