H. Furuya

Second-harmonic generation in Gd/sub x/Y/sub 1-x/Ca/sub 4/(BO/sub 3/)/sub 3/ thin films grown by combinatorial laser MBE

We report on the observation of second-harmonic generation in epitaxial Gd/sub x/Y/sub 1-x/Ca/sub 4/O(BO/sub 3/)/sub 3/ thin films with atomically smooth surfaces. Those films exhibit the noncritical phase-matching second-harmonic generation of neodymium-doped yttrium aluminum garnet lasers at room temperature.

Investigation of photo-induced damage in GdYCOB for high power UV lasers

We have investigated the photo-induced damage in GdYCOB crystals. It was found that the crystal grown in the air has more than three times higher tolerance of gray-tracking than that grown in an Ar atmosphere.

90/spl deg/ phase-matched second-harmonic generation in GdCa/sub 4/O(BO/sub 3/)/sub 3/ and YCa/sub 4/O(BO/sub 3/)/sub 3/

GdCa/sub 4/O(BO/sub 3/)/sub 3/ has been found to be 90/spl deg/ phase-matchable for type-1 SHG from 0.3622 /spl mu/m to 0.4129 /spl mu/m along y and from 0.4163 /spl mu/m to 0.4802 /spl mu/m along z by changing Gd molar concentration. The Sellmeiers equations of GdCa/sub 4/O(BO/sub 3/)/sub 3/ and YCa/sub 4/O(BO/sub 3/)/sub 3/ are also presented.

Crystal growth and characterization of gadolinium yttrium calcium oxyborate Gd/sub x/Y/sub 1-x/Ca/sub 4/O(BO/sub 3/)/sub 3/ for noncritically phase-matched SHG of a Nd:YAG laser

We have demonstrated noncritical phase matchable second harmonic generation of a Nd:YAG laser in Gd/sub 0.275/Y/sub 0.725/Ca/sub 4/O(BO/sub 3/)/sub 3/ (GdYCOB) at room temperature. The advantages, such as the high stability for angular and temperature variation, nonhygroscopicity, and ease in growing large crystals, suggest that the GdYCOB crystal is an attractive candidate for a high power green laser.

New nonlinear optical crystal GdYCOB for noncritically phase-matched UV generation

Summary form only given. In previous work, we reported that yttrium calcium oxyborate YCa/sub 4/O(BO/sub 3/)/sub 3/ (YCOB), which was an isomorph of GdCOB, was phase matchable for third-harmonic generation (THG) of Nd:YAG laser by type I sum frequency mixing, and it possessed moderate optical nonlinearity, sufficient mechanical hardness, and nonhygroscopicity. Recently, we succeeded to grow a substitutional solid solution of Gd/sub x/Y/sub 1-x/Ca/sub 4/O(BO/sub 3/)/sub 3/ (GdYCOB) with uniform composition. We could achieve a noncritically phase-matching (NCPM) at room temperature for THG of Nd:YAG laser with this crystal at x=0.24.

Yttrium calcium oxyborate YCa/sub 4/O(BO/sub 3/)/sub 3/ for blue and UV generation

Summary form only given. In recent years, many researchers have been devoted to the development of visible and UV lasers for industrial and medical applications. Although CdCa/sub 4/O(BO/sub 3/)/sub 3/ (GdCOB) presented by G. Aka ct al. is an attractive crystal that possesses a moderate optical nonlinear coefficient, a sufficient mechanical hardness, and a nonhygroscopicity, it cannot generate third-harmonic generation (THG) of the Nd:YAG fundamental because of small birefringence. The third harmonic could be obtained by using a YCa/sub 4/O(BO/sub 3/)/sub 3/ (YCOB) crystal, which is an isomorph of GdCOB. Furthermore, we succeeded to grow mixed crystals of Gd/sub x/Y/sub 1-x/Ca/sub 4/O(BO/sub 3/)/sub 3/ (O<x<l) with uniform composition, and tuned the noncritical phase-matching wavelength for second-harmonic generation (SHG) in the range from 0.83 to 0.97 /spl mu/m by changing the compositional parameter x. YCOB crystals were grown by the conventional RF-heating Czochralski method.