A method for improving the fluorescence output efficiency of Erbium-ytterbium co-doped laser crystal

Abstract

The invention belongs to the technical field of laser crystals and relates to a method for increasing the fluorescence output efficiency of an erbium and ytterbium co-doped laser crystal. By means ofthe characteristics that OH<-> ions easily enter and are combined with a rare-earth borate matrix crystal and the fact that the vibration frequency of OH<-> ions is close to a spacing between the <4>I<11 / 2> energy level and the <4>I<13 / 2> energy level of Er<3+> ions, through non-radiative energy transfer, OH<-> ions enables Er<3+> ions to rapidly transit from a <4>I<11 / 2> energy level to a <4>I<13 / 2> energy level, and enables other particles, which can transit to a higher energy level through approaches such as excited-state absorption, to rapidly transit to the<4>I<13 / 2> energy level, therebyeffectively shortening the service life of the <4>I<11 / 2> energy level of Er<3+>, improving the distribution proportion of the <4>I<13 / 2> energy level, furthermore, effectively improving the fluorescence output strength and efficiency of an Er<3+> / Yb<3+> co-doped rare earth borate crystal in a 1.5-1.6 [mu]m waveband, and lays a basis for efficient laser output of the crystal.

Description

Technical field: [0001] The invention belongs to the technical field of laser crystals, and relates to a method for improving the fluorescence output efficiency of an erbium-ytterbium co-doped laser crystal, in particular a method for improving the fluorescence output efficiency of an erbium-ytterbium co-doped rare earth borate laser crystal in the 1.5-1.6 μm band. Using OH in rare earth borate crystals - The vibration frequency of ions (about 2500 ~ 3600cm -1 ) and Er 3+ Ionic 4 I 11 / 2 with 4 I 13 / 2 Energy level interval (energy difference is about 3300cm -1 ) similar, OH - Ions can transfer Er through non-radiative energy transfer 3+ ion from 4 I 11 / 2 The energy level is quickly transferred to 4 I 13 / 2 energy level, effectively reducing Er 3+ of 4 I 11 / 2 Energy level lifetime, improved 4 I 13 / 2 The population ratio of the energy level can effectively improve the Er 3+ / Yb 3+ The fluorescence output intensity and efficiency of the co-doped rare earth borate...

AI Technical Summary

Problems solved by technology

These energy level transition processes make the erbium ion 4 I 11 / 2 The energy level lifetime is relatively long, resulting in the Yb 3+ ion to Er 3+ The process of reverse energy transfer of ions is enhanced, and 4 I 11 / 2 The long level lifetime of Er will also enhance the 3+ These will significantly reduce the pumping efficiency of the pump source, and reduce the slope efficiency of the 1.5-1.6 μm laser output from the crystal, which is difficult to meet practical requirements.

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