Yb^(3+):YAG crystal is one excellent material for developing high-power radiation-balanced lasers(RBLs).An experimental study of the laser cooling performances of YAG crystals with various doping Yb^(3+)concentrations...Yb^(3+):YAG crystal is one excellent material for developing high-power radiation-balanced lasers(RBLs).An experimental study of the laser cooling performances of YAG crystals with various doping Yb^(3+)concentrations,especially for application of RBLs,is reported here.With improved Yb^(3+)doping concentration in YAG crystal,though the resonance absorption coefficient increases,the corresponding external quantum efficiency has been found to decrease with the average fluorescence wavelength being red shifted,which is detrimental to anti-Stokes fluorescence(ASF)cooling.The decrease of the external quantum efficiency can cause the first zero crossing wavelength to red shift,which is not conducive to RBLs.Based on the comprehensive study of the cooling characteristics of the series of Yb^(3+)-doped YAG crystals,the optimal Yb3+doping concentration for ASF cooling has been suggested.展开更多
The micro mechanism of anti-Stokes fluorescent cooling was investigated on molecular or ionic scale. A new conception of single molecule-photon cryocooler (SMPC) was given, and the smallest cryocooler in the world was...The micro mechanism of anti-Stokes fluorescent cooling was investigated on molecular or ionic scale. A new conception of single molecule-photon cryocooler (SMPC) was given, and the smallest cryocooler in the world was predicted. We described SMPC and its running principle in detail. The quantum transition processes of SMPC and the largest cooling coefficient that SMPC can get in an optical transition were given. Also we studied the random property of SMPC in cooling processes. The thermodynamic behavior of single Yb3+ ion as a photon cryocooler was imitated.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.11604100,11834003,61574056,91536218,and 11874151)the Special Financial Grant from the China Postdoctoral Science Foundation(Grant No.2016T90346)111 Project(No.B12024).B.Zhong thanks L.Z.Deng for helpful discussions.
文摘Yb^(3+):YAG crystal is one excellent material for developing high-power radiation-balanced lasers(RBLs).An experimental study of the laser cooling performances of YAG crystals with various doping Yb^(3+)concentrations,especially for application of RBLs,is reported here.With improved Yb^(3+)doping concentration in YAG crystal,though the resonance absorption coefficient increases,the corresponding external quantum efficiency has been found to decrease with the average fluorescence wavelength being red shifted,which is detrimental to anti-Stokes fluorescence(ASF)cooling.The decrease of the external quantum efficiency can cause the first zero crossing wavelength to red shift,which is not conducive to RBLs.Based on the comprehensive study of the cooling characteristics of the series of Yb^(3+)-doped YAG crystals,the optimal Yb3+doping concentration for ASF cooling has been suggested.
基金This work was supported by the State Key Project of Basic Research (973 . Rare earth G1998061320) the Important Foundation of Chinese Academy of Sciences and the National Natural Science Foundation of China ( Grant Nos. 59872042, 69708003).
文摘The micro mechanism of anti-Stokes fluorescent cooling was investigated on molecular or ionic scale. A new conception of single molecule-photon cryocooler (SMPC) was given, and the smallest cryocooler in the world was predicted. We described SMPC and its running principle in detail. The quantum transition processes of SMPC and the largest cooling coefficient that SMPC can get in an optical transition were given. Also we studied the random property of SMPC in cooling processes. The thermodynamic behavior of single Yb3+ ion as a photon cryocooler was imitated.
