Synthesis and Performance of Advanced Ceramic Lasers

Abstract

This paper reports recent progress in the production of polycrystalline Nd:YAG (Y 3 Al 5 O 12 ), Nd:YSAG (Y 3 Sc 1.0 Al 4.0 O 12 ), Yb:YSAG ceramics, and a Nd-doped YAG single crystal with an almost perfect pore-free structure by advanced ceramic processing. The laser conversion efficiency of pore-free polycrystalline Nd-and Yb-doped ceramics is extremely high, and their optical qualities are comparable with that of commercial high-quality Nd:YAG single crystals. We have also succeeded in the fabrication of a Nd:YAG single crystal, which can be used for laser oscillation, by the solid-state reaction method. Laser oscillation efficiency was very low when the pores remained inside the single crystal; however, the laser oscillation efficiency of the pore-free Nd:YAG single crystal was slightly higher than that of polycrystalline Nd:YAG ceramics having high optical quality. From this fact, it was recognized that optical scattering occurs mainly in the residual pores inside the Nd:YAG ceramics and the scattering at the grain boundary is very less. In addition, we confirmed that a heavily doped Nd:YAG single crystal can be fabricated by the sintering method. Moreover, we have demonstrated the fabrication of a composite ceramic with complicated structures without the need for precise polishing and diffusion bonding. Advanced ceramic processing, which enables design flexibility of the laser element, presented in this work is important in the development of a high-performance laser (high efficiency, high beam quality, and high output energy, etc.) I. IntroductionJ ournal

Effective lattice stabilization of gadolinium aluminate garnet (GdAG) via Lu3+doping and development of highly efficient (Gd,Lu)AG:Eu3+red phosphors

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Nanopore Characterization and Optical Modeling of Transparent Polycrystalline Alumina

“…[13][14][15] One key feature and driving force of such activity is the possibility of sintering transparent ceramics to a near net shape, which has a potentially large economic and design impact, [ 16 ] particularly in comparison to machining the single-crystal bulk material. The general trend for reliable, mechanically robust ceramics has driven down grain sizes [ 17 , 18 ] to a regime requiring substantial attention to all the ceramic processing steps, from the powder synthesis to the sintering (i.e., fi ring).…”

Tailored Ceramics for Laser Applications

“…Ceramic amplifiers have many advantages over single crystals, including greater mechanical toughness [2], less residual stress, better optical homogeneity [3], and fewer constraints on dopant distribution and solubility.…”