【作者】 黄建华； 陈雨金； 林炎富； 龚兴红； 罗遵度； 黄艺东；

【Author】 Jianhua Huang YujinChen Yanfu Lin Xinghong Gong ZunduLuo Yidong Huang~* (Key Laboratory of Optoelectronic Materials Chemistry and Physics,Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences,Fuzhou,Fujian,350002)

【机构】 中国科学院福建物质结构研究所光电材料化学与物理重点实验室；

【摘要】 Er³⁺离子产生的1.55μm波段激光因对人眼安全,且位于大气传输窗口,在民用和军事等领域具有广阔应用前景。然而,目前在Er³⁺/Yb³⁺双掺低声子能量基质材料中(1000cm^-1以下)实现该波段激光输出的斜率效率均低于7%,这主要是由于该类晶体存在较强的上转换损耗。我们发现,在Er³⁺（1.0at.%）/Yb³⁺（10.7at.%）:NaGd（WO₄）₂（NGW）晶体中掺入43.3at.%的Ce³⁺离子后可实现效率高达19%的1.55μm激光输出,但激光运转过程中仍有微弱的绿光上转换损耗。因此,我们进一步采用提拉法生长了Er³⁺（0.98at.%）/Yb³⁺（10.04at.%）:NaCe（WO₄）₂（NCW）晶体。在同等实验条件下,测量了上述两晶体的非偏振上转换荧光光谱,发现Er³⁺/Yb³⁺:NCW晶体的上转换荧光强度远弱于Er³⁺/Yb³⁺/Ce³⁺:NGW晶体,这有利于进一步提高1.55μm波段激光的效率。我们还测量得到Er³⁺/Yb³⁺:NCW晶体中Er³⁺离子⁴I_13/2能级的荧光寿命为2.33ms。结果表明,Er³⁺/Yb³⁺:NCW晶体是一种可能获得低阈值高效率1.55μm激光的增益介质。更多还原

【Abstract】 Er laser around 1.55μm is located in the eye-safe range and atmospheric transmission window. Therefore,1.55μm laser has many practical applications in civil and military fields.However,the obtained slope efficiencies of the 1.55μm laser in the Er³⁺/Yb³⁺co-doped crystals with low phonon energy(below 1000 cm^-1)are generally lower than 7%,which is caused by the strong up-conversion losses.We found that the 1.55μm laser with a slope efficiency of 19%can be achieved in the Er³⁺（1.0at.%）/Yb³⁺（10.7at.%）:NaGd（WO₄）₂（NGW）crystal after the introduction of the 43.3at.%Ce³⁺ions. However,weak green up-conversion losses can still be seen during laser operation.Therefore,a Er³⁺（0.98at.%）/Yb³⁺（10.04at.%）:NaCe（WO₄）₂（NCW）crystal was grown by the Czochralski method.The un-polarized up-conversion fluorescence spectra of the above two crystals were measured under the same condition.It can be found that the up-conversion fluorescence of Er³⁺/Yb³⁺:NCW is much weaker than that of Er³⁺/Yb³⁺/Ce³⁺:NGW crystal,which is beneficial to further increasing the efficiency of 1.55μm laser.The fluorescence lifetime of the ⁴I_13/2level in the Er³⁺/Yb³⁺:NCW was measured to be 2.33ms.The results show that the Er³⁺/Yb³⁺:NCW crystal may be a 1.55μm laser gain medium with low threshold and high efficiency.更多还原