Laser ceramics with rare-earth-doped anisotropic materials.

The fabrication of laser-grade anisotropic ceramics by a conventional sintering process is not possible owing to optical scattering at randomly oriented grain boundaries. In this Letter, we report the first (to our knowledge) realization of transparent anisotropic ceramics by using a new crystal orientation process based on large magnetic anisotropy induced by 4f electrons. By slip casting in a 1.4 T magnetic field and subsequent heat treatments, we could successfully fabricate laser-grade calcium fluorapatite ceramics with a loss coefficient of 1.5 cm(-1).

[1]  Akio Ikesue,et al.  Fabrication and Optical Properties of High‐Performance Polycrystalline Nd:YAG Ceramics for Solid‐State Lasers , 1995 .

[2]  Y. Sakka,et al.  Orientation Amplification of Alumina by Colloidal Filtration in a Strong Magnetic Field and Sintering , 2001 .

[3]  Yan Lin Aung,et al.  Ceramic laser materials , 2008 .

[4]  Shiwei Wang,et al.  Transparent Polycrystalline Alumina Ceramics with Orientated Optical Axes , 2008 .

[5]  Bien Chann,et al.  Cryogenic Yb$^{3+}$-Doped Solid-State Lasers , 2007, IEEE Journal of Selected Topics in Quantum Electronics.

[6]  William F. Krupke,et al.  Ytterbium-doped apatite-structure crystals: A new class of laser materials , 1994 .

[7]  T. Taira,et al.  RE$^{3 +}$-Ion-Doped YAG Ceramic Lasers , 2007, IEEE Journal of Selected Topics in Quantum Electronics.

[8]  S. Asai,et al.  Formation of c-axis Aligned Polycrystal Hydroxyapatite Using High Magnetic Field with Mechanical Sample Rotation , 2005 .

[9]  Andy J. Bayramian,et al.  High-average-power femto-petawatt laser pumped by the Mercury laser facility , 2008 .

[10]  F. Lotgering,et al.  Topotactical reactions with ferrimagnetic oxides having hexagonal crystal structures—I , 1959 .

[11]  Yoichi Sato,et al.  Optical properties and laser characteristics of highly Nd3+-doped Y3Al5O12 ceramics , 2000 .

[12]  Lloyd L. Chase,et al.  Quantum electronic properties of the Na/sub 3/Ga/sub 2/Li/sub 3/F/sub 12/:Cr/sup 3+/ laser , 1988 .

[13]  Ken-ichi Ueda,et al.  Neodymium doped yttrium aluminum garnet (Y3Al5O12) nanocrystalline ceramics—a new generation of solid state laser and optical materials , 2002 .

[14]  Shigeki Tokita,et al.  Sapphire-conductive end-cooling of high power cryogenic Yb:YAG lasers , 2005 .

[15]  Y. Sakka,et al.  Control of Crystal Orientation of Hydroxyapatite by Imposition of a High Magnetic Field , 2003 .