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.
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 ±β 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.
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.
