【摘要】 提出了一种确定单层薄膜的光学常数和几何厚度的计算方法。通过讨论基于Fresnel的光学解析式,采用复合形法拟合分光光度计测得的反射率曲线,获得最优化的薄膜光学常数和厚度。然后采用此方法对理论模型薄膜加以验证,所得光学常数和厚度的最优解具有很好的一致性。此方法消除了单纯形法求解过程中存在的顶点退化问题,在整个优化求解过程中不需要初始值的输入,又由于考虑了约束条件,增加了显式和隐式方程约束,大大简化了计算和搜索范围,提高了收敛速度和计算精度。更多还原

【Abstract】 A new method to determine the optical constants and geometric thickness of single thin film is proposed with the measurement of the reflectance from spectrophotometer.Based on the Fresnel’s optical expression,improved flexible tolerance method is employed in the case of a digital model of thin film by fitting the curve of measured reflectance spectrum.Simulation results show a satisfactory coherence of the optical constants and the thickness of the target film.By taking the influence of nonlinear condition into account with more direct and indirect limitation,the precision and value-searching efficiency have been improved.Furthermore,the problem of dimension degradation,which exists in "Downhill Simplex?±,has been successfully avoided.No initial input is needed for the procedure of optimization to achieve optical solution,which makes the whole processing of value calculation much more convenient and efficient.更多还原