Er:NYW晶体绿光上转换饱和现象研究  

Investigation Into the Saturation Phenomena in Green Upconversion Luminescene of Er^(3+) Doped NaY(WO_4)_2 Crystal

作　　者：张康[1] 苏静[1] 韩琳[1] 闫立华[1] 张学智[1] 宋峰[1] 

机构地区：[1]南开大学光子学中心,弱光非线性光子学材料及其先进制备技术教育部重点实验室,天津300457

出　　处：《光电子．激光》2007年第1期71-73,共3页Journal of Optoelectronics·Laser

基　　金：新世纪优秀人才支持计划资助项目(560-903102;560-903103);教育部留学回国人员科研启动基金资助项目(b2a2023160);教育部优秀青年教师资助计划资助项目(c01177);南开大学学生创新基金资助项目

摘　　要：测得了974nmLD激发下Er3+掺杂NaY(WO4)2(ErNYW)晶体的上转换光谱,分析了550nm绿光4S3/2→4I15/2波段上转换发光强度随激发功率的变化关系,发现绿光的发射在较低激发功率下是双光子过程,而在较高激发功率下出现明显的饱和现象,上转换光的强度随着激发功率趋向于线性变化。分析得知,饱和的原因是激发态吸收(ESA)和能量转移上转换(ETU)2种过程的增强。并且发现,ESA和ETU的增强使得较多的Er3+被激发到更高能级,引起这些能级上转换紫光的发射。研究表明,紫光的发射是三光子过程,伴随着绿光发射的饱和而出现。In this paper, we measured the upconversion spectra of Er^3＋ doped NaY（WO4 ）2 （Er：NYW） crystal excited by a 974 nm laser diode. The pumping power dependency of green upconversion emission （4 S3/2 →4 I15/2 ） is measured to be twophoton process at low pumping power. However, obvious saturation phenomena in green emission occurs at high pumping power,that is,the emission intensity tends to increase linearly with the pumping power. The saturation mechanism is analyzed to be the result of enhanced excited state absorption（ESA） and energy transfer upconversion（ETU）. Additionally, the increased ESA and ETU pump more Er^3＋ ions to higher excited levels and produce violet upconversion emission. The violet emission is found to be a three-photon process,which concurs with the saturation of green emission.

关 键 词：上转换发光 饱和 NaY(WO4)2晶体 

分 类 号：TN244[电子电信—物理电子学]