Abstract

Yb:${\mathrm{CaYAlO}}_4$ (Yb:CYA) crystals with good optical qualities have been grown by the Czochralski method. The detailed polarized spectral properties, including absorption and fluorescence, were investigated. The results reveal a broadband emission feature ($\mathrm{FWHM}=77\mathrm{nm}$ at σ polarization). The fluorescence lifetime has been measured using the powder concentration dilution method, and the intrinsic lifetime was found to be $426\mathrm{\mu s}$. The thermal properties, including specific heat, thermal expansion, and thermal diffusion coefficients, have been investigated. The thermal conductivities were calculated to be 3.6 and $3.2\mathrm{W}/\mathrm{m}/\mathrm{K}$ along the a and c axes, respectively, at room temperature. The CW laser performances have been studied for both π and σ polarizations. The slope efficiencies of 55.4% and 41.4% were obtained for π- and σ-polarized operations, respectively. All the results show that Yb:CYA crystals should be excellent candidates as a laser medium for efficient and ultrafast lasers in the $1\mathrm{\mu m}$ region.

© 2011 Optical Society of America