Growth and characterization of TmxY1-x COB single crystals for nonlinear optical applications

Yttrium calcium oxyborate (YCOB) crystals are excellent nonlinear optical crystals. Tm-doped YCOB crystals, TmxY1-xCa4O(BO3)(3) (x = 0.1, 0.3, 0.5, 0.7, 0.9, and 1), were grown with the Bridgman method along the b-direction. A series of measurements including powder X-ray diffraction, density, X-ray fluorescence, transmission spectroscopy, specific heat, and thermal diffusion were carried out to verify the properties of the as-grown crystals. The results showed that these TmxY1-xCOB crystals are isostructural with YCOB and their segregation coefficients fall in the range of 0.9-1; meanwhile, they exhibit excellent thermal performance and are suitable for the quasi-parametric chirped-pulse amplification (OPCPA) application.