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\n\n\t\t