多次漫反射法测量粉末中的杂质吸收光谱及其计算机模拟

Muitiple diffuse reflection method for measuring absorption spectrum of impurity in powder sample its computer simulation

本文提出了用多次漫反射法来测定粉末样品的杂质吸收光谱,其结果与同材料的透明片状样品的杂质吸收光谱基本一致,为了验证更普遍的对不同折射率粉末情况,文中采用假设模型,以计算机模拟方法,其所得的结果说明,当颗粒足够小,色散又不太大时,所得的粉末样品与透明片状样品的吸收光谱一致,只差一个未知的吸收光程,如再与另一特性参数(寿命或量子效率)测量相结合,即可用来确定稀土杂质在材料中的辐射跃迁几率等物理参数。

A multiple diffuse reflection (MDR) method is proposed for measuring absorption spectrum of impurity in powder sample. I b has higher sensibiviby than single diffuse reflection method. An absorption spectrum deduced from the MDR spectrum is in good agreement with the absorption spectrum of clear plate sample. In order to verify the resulbs of different refractive index and dispersion, a randomized multiple diffuse reflection computer simulation model was designed to simulate the light beam travelling in the powder layer. The results illustrate that if the particle size is small enough and the dispersion of the meterial is not too high, the only difference between the absorption spectrum of powder sample and the absorption spectrum of clear plate sample is an unknown absorbing optical path. By combina-tion with other measuremente the radiative transition probabilities or intensity parameters can be obtained.