A highly Er3+-doped(10at.%) potassium ytterbium tungstate(Er3+:KYb(WO4)2, hereafter Er:KYbW) laser crystal was grown by the Kyropoulos method for the first time. The absorption and up-conversion emission spectra of Er:KYbW laser crystal were investigated at room temperature. Three obvious up- conversion emission bands were observed at the regions of 470-560, 645-675, 750-850 nm, and green up- conversion emission at 533 nm was much stronger. The mechanism of up-conversion emissions was discussed based on energy-matching principle. It was confirmed that two-photon process was involved in green and red up-conversion emissions. Based on Judd-Ofelt theory, the intensity parameters (=2,4,6) were: 2=16.34210-20 cm2, 4=4.18310-20 cm2, 6=1.26410-20 cm2. The calculated green up-conversion fluorescence branching ratios for 4S3/2-4I15/2 transition was 76.37%, and the radiative lifetime was 278 s. These optical parameters indicate that Er:KYbW is a highly efficient solid-state laser crystal for green up- conversion emission.
; Liu J.; Li C.; Lin H.; Zeng F.; Tonelli M.
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