enter(o)-
3.Chromium ion sensitizing laser self frequency doubling (SFD) crystal of Cr∶Nd∶GdCa 4O(BO 3) 3(Cr∶Nd∶GdCOB) was grown by CZ method,for the first time to our knowledge. The Chromium ion is easy to enter into the lattice of GdCOB crystal because of the co operative effect. The transmittance spectra and fluorescent spectra of Cr∶Nd∶GdCOB and Nd∶GdCOB crystals were measured at room temperature.

