A Yb_（0.11）Gd_（0.89）Ca_4O（BO_3）_3 crystal with new composition was grown by the Czochralski method. The crystal structure was measured and analyzed. The unit-cell parameters of the Yb_（0.11）Gd_（0.89）COB were...A Yb_（0.11）Gd_（0.89）Ca_4O（BO_3）_3 crystal with new composition was grown by the Czochralski method. The crystal structure was measured and analyzed. The unit-cell parameters of the Yb_（0.11）Gd_（0.89）COB were calculated to be a=0.8089（7） nm, b=1.5987（6） nm, c=0.3545（8） nm, β=101.22o. The absorption and fluorescence spectra were measured. The maximum absorption cross-section of Yb_（0.11）Gd_（0.89） COB crystal was 0.79×10^（–20）cm^2, which occurred at 976 nm with Y polarization. The emission cross-section at 1027 nm was calculated to be 0.33×10^（–20） cm^2. The radiative lifetime trad was calculated to be 2.74 ms. The Stark energy-level diagram of Yb^（3＋）in the Yb_（0.11）Gd_（0.89）COB crystal field at room temperature was determined. The ground-state energy level ~2F_（7/2） splitting was calculated to be as large as 1004 cm^（–1） and the zero-line energy was 10246 cm^（–1）. A maximum output power of 9.35 W was achieved in continuous-wave（CW） mode, with the slope efficiency being 42.1%. Chemical etching experiment revealed that the dominating imperfections in the studied Yb_（0.11）Gd_（0.89） COB crystal were dislocations and sub-grain boundaries. The existence of crystal defects could cause light scattering, and degrade laser output efficiency. The influence of crystal defects on laser properties was discussed.展开更多
基金Project supported by National Natural Science Foundation of China(11204148,11374170)Taishan Scholar Program of Shandong Province+2 种基金Open Project of State Key Laboratory of Rare Earth Resource Utilization(RERU2016015)the Applied Basic Research Programs for Youths of Qingdao(15-9-1-52-JCH)Qingdao Postdoctoral Application Research Project(2015127)
文摘A Yb_（0.11）Gd_（0.89）Ca_4O（BO_3）_3 crystal with new composition was grown by the Czochralski method. The crystal structure was measured and analyzed. The unit-cell parameters of the Yb_（0.11）Gd_（0.89）COB were calculated to be a=0.8089（7） nm, b=1.5987（6） nm, c=0.3545（8） nm, β=101.22o. The absorption and fluorescence spectra were measured. The maximum absorption cross-section of Yb_（0.11）Gd_（0.89） COB crystal was 0.79×10^（–20）cm^2, which occurred at 976 nm with Y polarization. The emission cross-section at 1027 nm was calculated to be 0.33×10^（–20） cm^2. The radiative lifetime trad was calculated to be 2.74 ms. The Stark energy-level diagram of Yb^（3＋）in the Yb_（0.11）Gd_（0.89）COB crystal field at room temperature was determined. The ground-state energy level ~2F_（7/2） splitting was calculated to be as large as 1004 cm^（–1） and the zero-line energy was 10246 cm^（–1）. A maximum output power of 9.35 W was achieved in continuous-wave（CW） mode, with the slope efficiency being 42.1%. Chemical etching experiment revealed that the dominating imperfections in the studied Yb_（0.11）Gd_（0.89） COB crystal were dislocations and sub-grain boundaries. The existence of crystal defects could cause light scattering, and degrade laser output efficiency. The influence of crystal defects on laser properties was discussed.
