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Abstract: For the first time, a high optical quality Yb3+-doped lutetium pyrosilicate laser crystal Lu2Si2O7 (LPS) was grown by the Czochralski (Cz) method. The segregation coefficient of ytterbium ion in Yb:LPS crystal detected by the inductively coupled plasma atomic emission spectrometer (ICP-AES) method is equal to 0.847. X-ray powder diffraction result confirms the C2/m phase monoclinic space group of the grown crystal and the peaks corresponding to different phases were indexed. The absorption and fluorescence spectra, as well as fluorescence decay lifetime of Yb3+ ion in LPS have been investigated. The absorption and fluorescence cross-sections of the transitions 2F7/2↔2F5/2 of Yb3+ ion in LPS crystal have been determined. The advantages of the Yb:LPS crystal including high crystal quality, quasi-four-level laser operating scheme, high absorption cross-sections (1.33×10−20 cm2) and particularly broad emission bandwidth (∼62nm) indicated that the Yb:LPS crystal seemed to be a promising candidate used as compact, efficient thin chip lasers when LD is pumped at 940 and 980nm due to its low-symmetry monoclinic structure and single crystallographic site. [Copyright &y& Elsevier]

Abstract: Undoped LaAlO3 and Ce-doped LaAlO3 single crystals were grown by the Czochralski process. The segregation coefficient of cerium ions in 1at% Ce: LaAlO3 is 0.28. The undoped LaAlO3 and Ce-doped LaAlO3 single crystals were characterized by infrared transmission spectra and ultraviolet/visible/near-IR absorption spectra. It was observed that the band-to-band absorption of LaAlO3 host is around 209nm. Four characteristic f–f transitions of Ce3+ ion at 1923, 2354, 2669, and 3728cm-1 and five f–d transitions around 198, 206, 214, 246, and 316nm in the Ce-doped LaAlO3 crystal were observed. Strong emission around 410nm was also observed at excitation of 317nm in the Ce-doped LaAlO3 single crystal. [Copyright &y& Elsevier]