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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