CSIST Has Made Progress in the Research of High Efficiency Radiation Resistance Mid Infrared Laser Crystal

2.7~3μm mid infrared laser has important potential application in spectrum analysis, gas detection, laser medicine as well as optical parametric oscillator pumped laser and other areas. Recently, funded by the National Natural Science Fund, a research group lead by SunDun Lu, a researcher from the laser center of Anhui Institute of Optics and Fine Mechanics, Hefei Institute of material science has made a series progress in the research of high efficiency radiation resistance 2.7~3μm mid infrared laser crystal; and has published its research results in Optics Letters,Optics Express.

As for the research of radiation resistance function of laser crystal, researchers has made comparative study about the features of absorption, fluorescence spectrum, level lifetime, laser characteristics and others of Er:GYSGG、Yb,Er,Ho:GYSGG crystal before and after irradiated by 100 Mrad γ ray; results shows that this new type crystal has excellent radiation resistance (Optics Letters, 2013, 38:1218-1220).

 

As for the improvement of mid infrared crystal laser efficiency and high repetitive frequency laser characteristics, researchers mixed in retreat activated ions such as Pr3+, Ho3+ and sensitized ions such as Yb3+, Cr3+; so as to study their impact on Er:GYSGG crystal’s absorption, fluorescence spectrum, level lifetime, laser characteristics and other functions. Results showed that after the mix of retreat activated ions, the laser lower level lifetime of the crystal was reduced, laser efficiency and high repetitive frequency laser characteristics were improved, which laid the foundation for the practical application of the crystal.

 

Furthermore, the research group has been studying crystal thermal bonding technology and the relevant functions. As for GYSGG/Er,Pr:GYSGG thermal bonding composite laser crystal, temperature of the crystal end was lowered, thermal lensing effect was improved, the laser characteristic was obviously increased, pure GYSGG crystal if used as end cap could have the effect of heat sink cooling, and that could realize high performance LD end pumped solid laser (Optics Express, 2014,22:23795-23800).

 

Related work is funded by General Project as well as Training Program of the Major Research Plan of the National Natural Science Foundation of China.

                                          

Chart 1. Laser output power curve of Yb,Er,Ho:GYSGG before and after irradiated by 100 Mrad γ ray

Chart 2. Laser Characteristic curve of Cr,Er,Pr:GYSGG at repeat frequency rate 1~60Hz

                                         

Chart 3. Upper and lower level fluorescence decay curve of Er,Pr:GYSGG

Chart 4. Temperature distribution of end pumped Er,Pr:GYSGGG and GYSGG/Er,Pr:GYSGG

Chart 5. Laser output power characteristics of end pumped Er,Pr:GYSGG and GYSGG/Er,Pr:GYSGG