以不同孔径的阳极氧化铝(AAO)多孔材料作为研究对象,基于高速摄影和原子发射光谱分别研究了AAO孔径对激光诱导等离子体形态演变和温度的影响,利用吸收光谱及时域有限差分法对样品的光反射率进行测试与仿真分析。研究结果表明:在一定的孔径范围内,随着AAO孔径减小,等离子体的存在时间变长,光谱谱线强度变大,等离子体的电子温度升高;AAO的等离子体参数均大于抛光铝片的,其电子温度比抛光铝片的高2000~3500 K;在一定的孔径范围内,AAO孔径越小,光在样品内部的吸收系数越高,解释了等离子体增强的原因。

Taking anodic aluminum oxide (AAO) with different pore diameters as research object,we study the effects of pore size of AAO on the morphological evolution and temperature of laser-induced plasma based on high-speed photography and atomic emission spectroscopy. The light reflectance of samples is tested and simulated by absorption spectroscopy and finite-difference time-domain (FDTD) method.The results show that within a certain pore range, as the AAO pore size decreases, plasma duration becomes long, the spectral line intensity becomes large, and the plasma electron temperature becomes high. The plasma parameters of AAO are larger than those of polished aluminum sheet, in which electron temperature of plasma of AAO is 2000-3500 K higher than that of polished aluminum sheet. Within a certain pore range, the smaller the AAO pore, the higher absorption coefficient of light in the sample, which explains the reason of AAO plasma enhancement.