- R&D 100 Awards
2014 R&D 100 Winner Efforts to scale the power of a single-output laser to more than 100 kW have encountered significant challenges in removing waste heat, maintaining beam quality and avoiding optical damage to output optics. Electrically driven solid-state lasers have been demonstrated at this power level, but the thermo-optical distortions in the bulk laser materials demonstrated to date result in degraded beam quality, which limits the irradiance delivered to a target.
Spectral beam combining (SBC) of fiber lasers offers a straightforward approach for power scaling. The approach exploits the broad gain bandwidth to enable large numbers of fiber laser channels to be combined with near-diffraction-limited beam quality. Rigorous application of SBC has allowed a development team including Lawrence Livermore National Laboratory, Lockheed Martin Laser and Sensor Systems and Advanced Thin Films to develop the EXtreme-power, Ultra-low-loss, Dispersive Element (EXUDE) optical element, the first-ever electrically efficient, near diffraction-limited 30-kW beam combined laser. Key underlying technologies include proprietary optical coating designs using more than 100 thin-film layers that enable ultra-low-loss transmission levels. This and other enabling technologies, such as dispersive surface relief structure design, allow single 30-kW beams of light at more than 98% efficiency, and project maximum output of more than 100 kW.
Technology Near diffraction-limited 30-kW beam combined laser
The EXtreme-power, Ultra-low-loss, Dispersive Element (EXUDE) Development Team Jerry A. Britten, Principal Developer, Lawrence Livermore National LaboratoryEric Honea, Principal Developer, Lockheed Martin Laser and Sensor SystemsRamin Lalezari, Principal Developer, Advanced Thin FilmsMichael D. Aasen, Lawrence Livermore National LaboratoryRobert Afzal, Lockheed Martin Laser and Sensor SystemsJeffrey Cao, Lockheed Martin Laser and Sensor SystemsThomas C. Carlson, Lawrence Livermore National LaboratoryHoward Champoux, Advanced Thin FilmsMark Feldman, Lockheed Martin Laser and Sensor SystemsCurly R. Hoaglan, Lawrence Livermore National LaboratoryDan Hu, Lockheed Martin Laser and Sensor SystemsDon Jander, Lockheed Martin Laser and Sensor SystemsCindy C. Larson, Lawrence Livermore National LaboratoryHoang T. Nguyen, Lawrence Livermore National LaboratoryJames D. Nissen, Lawrence Livermore National LaboratoryTracy Vatter, Lockheed Martin Laser and Sensor Systems