Two modulator generalized ellipsometer for complete mueller matrix
measurement
    1.
    发明授权
    Two modulator generalized ellipsometer for complete mueller matrix measurement 失效
    两个调制器广义椭偏仪,用于完整的米勒矩阵测量

    公开(公告)号:US5956147A

    公开(公告)日:1999-09-21

    申请号:US874365

    申请日:1997-06-13

    IPC分类号: G01B11/06 G01J4/00 G01N21/21

    摘要: A two-modulator generalized ellipsometer (2-MGE) comprising two polarizer-photoelastic modulator (PEM) pairs, an optical light source, an optical detection system, and associated data processing and control electronics, where the PEMs are free-running. The input light passes through the first polarizer-PEM pair, reflects off the sample surface or passes through the sample, passes through the second PEM-polarizer pair, and is detected. Each PEM is free running and operates at a different resonant frequency, e.g., 50 and 60 kHz. The resulting time-dependent waveform of the light intensity is a complicated function of time, and depends upon the exact operating frequency and phase of each PEM, the sample, and the azimuthal angles of the polarizer-PEM pairs, but can be resolved into a dc component and eight periodic components. In one embodiment, the waveform is analyzed using a new spectral analysis technique that is similar to Fourier analysis to determine eight sample Mueller matrix elements (normalized to the m.sub.00 Mueller matrix element). The other seven normalized elements of the general 4.times.4 Mueller matrix can be determined by changing the azimuthal angles of the PEM-polarizer pairs with respect to the plane of incidence. Since this instrument can measure all elements of the sample Mueller matrix, it is much more powerful than standard ellipsometers.

    摘要翻译: 包括两个偏振器 - 光弹性调制器(PEM)对的双调制器广义椭偏仪(2-MGE),光学光源,光学检测系统和相关联的数据处理和控制电子器件,其中PEM是自由运行的。 输入光通过第一偏振器-PEM对,从样品表面反射或通过样品,通过第二PEM偏振器对,并被检测。 每个PEM是自由运行的,并且以不同的谐振频率(例如50和60kHz)工作。 所产生的光强度的时间依赖波形是时间的复杂函数,并且取决于每个PEM,样品和偏振器-PEM对的方位角的精确工作频率和相位,但是可以解析为 直流分量和八个周期分量。 在一个实施例中,使用类似于傅立叶分析的新的光谱分析技术来分析波形,以确定八个采样Mueller矩阵元素(归一化为m00Mereller矩阵元素)。 可以通过改变PEM偏振器对相对于入射平面的方位角来确定通用4×4 Mueller矩阵的其他七个归一化元素。 由于该仪器可以测量样品Mueller矩阵的所有元素,因此它比标准椭偏仪更强大。