Birefringent thin-film polarizers for use at normal incidence and with planar technologies

摘要: We discuss the design and fabrication of an all-dielectric thin-film polarizer that is compatible with existing planar technologies. This consists a stack quarter-wave biaxial layers. Each layer formed by reactive electron-beam evaporation, using bideposition technique causes columnar structure to grow perpendicular substrate, produces large normal-incidence linear birefringence, avoids thickness wedging inherent in tilted-columnar p-polarized light incident on encounters index-matched transmitted, whereas s-polarized rejected coexisting high-reflectance stack. A figure-of-merit ten film periods per decade extinction ratio has been achieved practice for titanium oxide/tantalum oxide polarizer.