Page 238 - High Power Laser Handbook
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CHAPTER 9







                                                  Nd:YAG Ceramic

                                                      ®
                                        ThinZag  High-Power

                                           Laser Development






                      Daniel E. Klimek
                      Principal Research Scientist, Textron Defense Systems,
                        Wilmington, Massachusetts

                      Alexander Mandl
                      Principal Research Scientist, Textron Defense Systems,
                        Wilmington, Massachusetts







                 9.1  Introduction and ThinZag Concept Development
                      Over the past decade, solid-state lasers have demonstrated remark-
                      able power in scaling. To a large extent, the emergence of solid-
                      state  lasers  as  competitive  high-power  devices  is  due  to  the
                      availability of highly efficient (~60 percent), high-power (> 100 W),
                      low-cost (< $10/W mounted) laser diode bars.
                         As a laser gain material, Nd:YAG is by far the most commonly
                      used  in  solid-state  lasers,  due  to  a  combination  of  properties  that
                      uniquely  favor  high-power  laser  performance.  The  YAG  host  is  a
                      robust,  fracture-resistant  material  with  high  thermal  conductivity.
                      Nd:YAG also has a narrow fluorescent line width, which results in
                      high gain. There has also been a revolutionary development in laser
                      gain material. Cubic structure materials like YAG can now be fabri-
                      cated as ceramics with optical uniformity that is better than found in
                      YAG crystals (for both dopant uniformity and variations in index of
                      refraction), with scattering loss coefficients comparable to YAG crystals

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