Homogeneity analysis of sculptured thin films deposited in symmetric style through glancing angle deposition technique

The symmetric deposition technique is often used to improve the uniformity of sculptured thin film （STF）. In this paper, optical properties of STF with the columnar angles 4-/3 are analyzed theoretically, based on the characteristic matrix method for extraordinary waves. Then, the transmittances of uniformity monolayer and bilayer STF in symmetrical style are calculated to show the effect of the bilayer structure on the optical properties of STF. The inhomogeneity of STF is involved in analyzing the differences in transmittance and phase retardation between monolayer and bilayer STF deposited in symmetric style. The results show that optical homogeneity of STF can be improved by depositing in symmetric style at the normal incidence, but it is not the same case as the oblique incidence.     

高温高压模拟井筒应力分析与评价

模拟井筒是用于模拟油田井下高温高压环境的实验装置，为高温高压厚壁容器.基于热力学及大涡模拟(LES)理论，建立了模拟井筒温度场物理方程.基于热弹性力学理论，建立了热应力物理方程.采用投影法求解温度场控制方程，采用梯形法数值积分求解热应力控制方程，给出了控制方程的离散格式.通过虚拟密度法对流固耦合传热进行求解，根据应力叠加原理对模拟井筒热应力和压应力及其耦合作用进行了数值求解分析.研究结果表明：设计壁厚最小值为0.18 m的模拟井筒，强度能够满足在400℃加热环境、内部加压220 MPa工作参数下进行高温高压实验.通过实验验证了所建立的数学模型与数值求解方法的正确性，为高温高压厚壁容器设计提供了理论依据.     

The design and preparation of a Fabry-Perot polarizing filter

A novel single-cavity narrowband Fabry-Perot （FP） polarizing filter at normal incidence, constructed from a sandwich structure with sculptured anisotropic space layer and symmetric isotropic HR mirrors, is designed and prepared. The optical performances of transmittance, phase shift, central wavelength, and bandwidth for two polarized states are analyzed with the characteristic matrix. The numerical studies accord reasonably well with the experimental results. It is demonstrated that the polarization state of the electromagnetic wave and phase shift can be modulated by employing an anisotropic space layer in the polarizing beam splitter system. The birefringence of the anisotropic space layer provides a sophisticated phase modulation by varying the incidence angles over a broad range to have a wide-angle phase shift.     

Phase shift of polarized light through sculptured thin films: Experimental measurements and theoretical study

A slanted columnar TiO2 sculptured anisotropic thin film （ATF） is prepared via the glancing angle deposition technique and used as the phase retardation plate. The tilted nanocolumn microstructures of thin film induce the optical anisotropy. With the biaxial birefringent model, the optical constants dispersion equations of TiO2 ATF are derived by fitting the transmittance spectra for s-and p-polarized waves measured at normal and oblique incidence within 400 nm–1200 nm. The phase shift of polarized light after reflection and/or transmission through the TiO2 ATF is analyzed with the characteristic matrix employing the extracted structure parameters. The theoretical studies reasonably well accord with the experimental results measured with spectroscopic ellipsometry. In addition, the dependences of the phase shift on the coating physical thickness and oblique incidence angle are also discussed. Birefringence of the biaxial ATF provides a sophisticated phase modulation by varying incidence angles over a broad range to have a wide-angle phase shift.     

The design and preparation of a Fabry–Pérot polarizing filter

A novel single-cavity narrowband Fabry–Pe′rot(FP) polarizing filter at normal incidence,constructed from a sandwich structure with sculptured anisotropic space layer and symmetric isotropic HR mirrors,is designed and prepared.The optical performances of transmittance,phase shift,central wavelength,and bandwidth for two polarized states are analyzed with the characteristic matrix.The numerical studies accord reasonably well with the experimental results.It is demonstrated that the polarization state of the electromagnetic wave and phase shift can be modulated by employing an anisotropic space layer in the polarizing beam splitter system.The birefringence of the anisotropic space layer provides a sophisticated phase modulation by varying the incidence angles over a broad range to have a wide-angle phase shift.