In this work, the birefringence of bideposited symmetric nanorod array is investigated. The Ta2O5 nanorod arrays composed of several subdeposits are fabricated by serial bideposition (SBD) technique. Each nanorod consists of several identical units and each unit consists of symmetrical sections ABA. From the lateral view of the structure, the nanorod array is a symmetrical multilayered. The deposition planes for layer A and layer B are perpendicular to each other. For normal incident ray, the polarization-dependent refractive indices and phase thicknesses of the film are presented as functions of wavelength and optical constants of each layer. The transmittance spectra of symmetrical sections have a pass band property as the equivalent refractive indices are real. The principal indices of the Ta2O5 nanorod arrays with each subideposition thickness of 3 nm associated with the two orthogonal polarizations are measured by ellipsometer when the deposition angle is changed from 70° to 80°. According to principal indices database, a uniform phase retardation between the two orthogonal polarization directions can be designed for a specific wavelength range.© (2011) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.