Effects of Neodymium Concentration on Optical Characteristics of Polycrystalline Nd:YAG Laser Materials

A neodymium-doped yttrium-aluminum garnet (Y{sub 3}Al{sub 5}O{sub 12}, YAG) (Nd:YAG) ceramic that contained 0.3--4.8 at.% neodymium additives and exhibited nearly the same optical properties as those of a single crystal was fabricated by a solid-state reaction method using high-purity powders. Although the integrated absorption intensity of the {sup 2}H{sub 9/2} + {sup 4}F{sub 5/2} bands simply increased as the neodymium concentration in the YAG ceramics decreased, the fluorescence intensity of the 2.4 at.% Nd:YAG ceramic was the strongest among Nd:YAG ceramics with various neodymium concentrations and a 0.9 at.% Nd:YAG single crystal. An oscillation experiment was performed on a continuous-wave (cw) laser with a diode-laser exciting system using those ceramics and the single crystal. The oscillation threshold and slope efficiency in that analysis were 309 mW and 28%, respectively, for the 1.1 at.% Nd:YAG ceramics and 356 mW and 40%, respectively, for the 2.4 at.% Nd:YAG ceramics. The lasing characteristics of the ceramics in the present work were superior to those of a 0.9 at.% Nd:YAG single crystal that was fabricated by the Czochralski (Cz) method.

[1]  J. Caird,et al.  Measurements of losses and lasing efficiency in GSGG:Cr,Nd and YAG:Nd laser rods. , 1986, Applied optics.

[2]  S. Kimura,et al.  Induced emission cross section of Nd:Y3Al5O12 grown by floating zone method , 1983 .

[3]  R. Monchamp.  The distribution coefficient on neodymium and lutetium in Czochralski grown Y3Al5O12 , 1971 .

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

[5]  R. Autrata,et al.  Czochralski growth of YAG:Ce in a reducing protective atmosphere , 1981 .

[6]  B. Cockayne,et al.  Facetting and optical perfection in Czochralski grown garnets and ruby , 1969 .

[7]  A. Ikesue,et al.  Role of Si on Nd Solid-Solution of YAG Ceramics , 1995 .

[8]  Akio Ikesue,et al.  Fabrication of Polycrystal line, Transparent YAG Ceramics by a Solid‐State Reaction Method , 1995 .

[9]  M. Birnbaum,et al.  Laser emission cross section of Nd:YAG at 1064 nm , 1981 .

[10]  J. A. Osmer,et al.  Habit changes of Y3Al5O12 and Y3Ga5O12 grown from a PbO-PbF2 flux , 1969 .

[11]  R. Roth,et al.  Solid State Reactions Involving Oxides of Trivalent Cations , 1961, Journal of research of the National Bureau of Standards. Section A, Physics and chemistry.

[12]  J. Geusic,et al.  LASER OSCILLATIONS IN Nd‐DOPED YTTRIUM ALUMINUM, YTTRIUM GALLIUM AND GADOLINIUM GARNETS , 1964 .

[13]  T. Yanagitani,et al.  Induced emission cross section of Nd:Y3Al5O12 ceramics , 1990 .

[14]  T. Sekino,et al.  Progress in the YAG Crystal Growth Techniqe for Solid State Lasers , 1993 .