摘要
Two zero-phonon lines with wide linewidth on R_(1)^(- ) and unknown colour centres have been observed in the magnesium-doped lithium fluoride crystals coloured by electron beam bombardment at 200 K in the measured temperature range of 10-77 K. The R_(1)^(- )zero-phonon line can be nearly completely bleached using the normal spectrophotometer light at 10K. An obvious spectral burning hole in the absorption profile of the R_(1)^(- ) zero-phonon line of colour centres in the coloured lithium fluoride crystals has been obtained by using the spectrophotometer light adjusted to narrower bandwidth at 10K. The optical bleaching of the zero-phonon line can be partially recovered by annealing the crystals to room temperature for a short time period or irradiating the crystals with ultraviolet light above 40 K, and nearly complete restoration can be obtained after the ultraviolet light irradiation and storage in the dark for a long time at room temperature.
作者
顾洪恩
王克起
刘洪海
GU Hong-En;WANG Ke-Qi;LIU Hong-Hai(Department of Applied Physics,Tianjin University,Tianjin 300072)
基金
Supported partially by the National Natural Science Foundation of China under Grant No.69178028。