Nee S M
Physics Branch, Research and Technology Group, Weapons Division, Naval Air Warfare Center, China Lake, California 93555-6001, USA.
Appl Opt. 1999 Sep 1;38(25):5388-98. doi: 10.1364/ao.38.005388.
Null ellipsometry is analyzed for components with depolarizations for unpolarized incident light. Serious imperfections include sample depolarization D < 0.2, misalignment (deltaC < 2 degrees) and off-quarter-wave retardance (deltatau < 5 degrees) of the compensator. The four-zone null positions are derived analytically to the second order of serious imperfections and are also simulated based on Mueller matrices with depolarization. Errors of all four-zone nulls increase with increasing D. Depolarizations of all components except the analyzer cause errors to the nulls. The errors associated with D always couple with the second order of deltaC and deltatau and are enhanced by csc(2) 2psi. These divergent errors limit the applicable region of null ellipsometry where the errors in psi and D are within 0.1 degrees, and the simulation agrees well with the analytic solutions.
针对非偏振入射光下具有退偏特性的组件，对零位椭圆偏振法进行了分析。严重的缺陷包括样品退偏D < 0.2、对准误差（δC < 2度）以及补偿器的偏离四分之一波长延迟（δτ < 5度）。通过解析方法推导了四区域零位位置至严重缺陷的二阶项，并基于带有退偏的穆勒矩阵进行了模拟。所有四区域零位的误差均随D的增加而增大。除检偏器外的所有组件的退偏都会导致零位误差。与D相关的误差总是与δC和δτ的二阶项耦合，并通过csc(2) 2ψ得到增强。这些发散误差限制了零位椭圆偏振法的适用范围，在该范围内ψ和D的误差在0.1度以内，且模拟结果与解析解吻合良好。
