Division of Convergence Technology, Korea Research Institute of Standards and Science, 1 Doryong-Dong, Yuseong-Gu, Daejeon 305-340, South Korea.
Opt Lett. 2011 Jan 15;36(2):118-20. doi: 10.1364/OL.36.000118.
We introduce a Fourier analysis of the waveform of periodic light-irradiance variation to capture Fourier coefficients for multichannel rotating-element ellipsometers. In this analysis, the Fourier coefficients for a sample are obtained using a discrete Fourier transform on the exposures. The analysis gives a generic function that encompasses the discrete Fourier transform or the Hadamard transform, depending on the specific conditions. Unlike the Hadamard transform, a well-known data acquisition method that is used only for conventional multichannel rotating-element ellipsometers with line arrays with specific readout-mode timing, this Fourier analysis is applicable to various line arrays with either nonoverlap or overlap readout-mode timing. To assess the effects of the novel Fourier analysis, the Fourier coefficients for a sample were measured with a custom-built rotating-polarizer ellipsometer, using this Fourier analysis with various numbers of scans, integration times, and rotational speeds of the polarizer.
我们介绍了一种周期性光辐照度变化波形的傅里叶分析方法，以捕获多通道旋转元件椭偏仪的傅里叶系数。在这种分析中，使用对曝光的离散傅里叶变换来获得样品的傅里叶系数。该分析给出了一个通用函数，该函数包含离散傅里叶变换或 Hadamard 变换，具体取决于特定条件。与 Hadamard 变换不同，Hadamard 变换是一种仅用于具有特定读出模式定时的线阵的传统多通道旋转元件椭偏仪的常用数据采集方法，这种傅里叶分析适用于具有非重叠或重叠读出模式定时的各种线阵。为了评估新的傅里叶分析的效果，使用定制的旋转偏振器椭偏仪，使用此傅里叶分析，以各种扫描次数、积分时间和偏振器的旋转速度测量了样品的傅里叶系数。
