Nd：YbVO4晶体的拉曼光谱和荧光光谱研究

用群论的方法计算了Nd：YbVO4晶体的拉曼活性振动模数目，在室温下测得了其极化拉曼谱线，并指认了在不同几何配置下，各振动模式所对应的频率。同时，测得了室温下晶体的吸收谱，得到了中心波长为808am吸收峰的半高宽为12nm，并在J-O理论的基础上计算了晶体的光学参数，其三个晶场参数分别为Ω2=6．88945×10^-20cm^2。Ω4=4．13394×10^-20cm^2、Ω6=4．54503×10^-20cm^2，并由此得到^4F3／2能级的荧光寿命为178．69炉，1062nm处的荧光分支比为48．85％，积分发射截面为2．786710^-18cm^2。分别在808nm、940nm激发下测得晶体室温发射谱，观察到了Nd→Yb以及Nd←Yb间的能量传递现象。

The number of Raman-active vibration mode for Nd:YbVO<inf>4</inf> crystal has been calculated according to group theory. The polarized Raman spectra have been measured at room temperature, and the frequency corresponding Raman-active vibration mode with different scattering geometry have been signed. The absorption spectra were measured at room temperature and the full width at half maximum of absorption peak at central wavelength of 808 nm is 12 nm. Based on the Judd-Ofelt theory, the three intensity parameters have been calculated and the results are Ω<inf>2</inf>=6.88945×10^-20 cm², Ω<inf>4</inf>=4.13394×10^-20 cm² and Ω<inf>6</inf>=4.54503×10^-20 cm². The radiative lifetime of ⁴F<inf>3/2</inf> is 178.69 μs, branching ratio at 1062 nm is 48.85%, differential stimulated -emission cross section is 2.7867 10^-18 cm². From the fluorescent spectra excited by 808 nm and 940 nm, the Nd&rarrYb and Nd←Yb energy transfer have been observed.