橢偏儀

 

 

Theory of Ellipsometry

After reflection on a sample surface, a linearly polarized light beam is generally elliptically polarized. The reflected light has phase changes that are different for electric field components polarized parallel (p) and perpendicular (s) to the plane of incidence. Ellipsometry measure this state of polarization or more precisely the complex ratio rho written as:

ρ = rp/rs = tanΨ * exp (iΔ)
Where Psi and Delta are the amplitude ratio and phase shift, respectively, of the p and s components and are the ellipsometric parameters (often given as tan Psi, cos Delta) measured as described in the Signal treatment and calibration section. The reflectance coefficients are directly related to the optical constants of the surface by assuming the ambient is air ( Fresnel relations ):

rp = ncosΦi - cosΦr / ncosΦi + cosΦr
ri = cosΦi - ncosΦr / cosΦi + ncosΦr
when n is the complex refractive index n = N - ik of the surface. The angle of refraction may be obtained using Snell-Descartes's Law:

sinΦi = nsinΦr

Thus if the sample is an ideal bulk, the real and imaginary parts of the complex refractive index may be calculated from the measured tan Psi and cos Delta parameters with the knowledge of the incidence angle. The optical index and thickness of a transparent layer on known substrate can also be deduced in the same way. This kind of analysis is characteristic of a single wavelength ellipsometric measurement.

 
微信猜大小单双二维码 破解北京pk10双面盘玩法 比分网足球即时比分 大赢家体育比分登录 彩票快3选号技巧 扑克二十一点怎么玩 麻将技巧顺口溜 11选5拖胆玩法 三期必開一期永久 香港马会资枓大全三肖 分分快3怎么玩 红马计划软件怎么下载 发财计划官网网址 106码倍投方法 贝贝游戏通比牛牛技巧 西安二人麻将技巧