Paper SE-ThP3
Characterizations of Polarization-Discriminatory Inverters Fabricated by Glancing Angle Deposition

Thursday, October 23, 2008, 6:00 pm, Room Hall D

Glancing angle deposition (GLAD) is a thin-film fabrication technique with controlled microstructures and provides advantages over conventional evaporation techniques. Based on physical vapor deposition, it employs an oblique-angle-deposition and substrate motion to allow nanometer-scale control of the structure in engineered thin-film materials. The films deposited in this technique show the optical anisotropy originating from the microstructures and the porosity of the films increase due to shadow effects. These controls can be utilized to engineer thin films for specific applications such as three-dimensional photonic crystals, gradient index optical filters, broadband antireflection coatings, and linear polarizer, etc. In this study, we investigate the optical and structural properties of linear and circular polarization-discriminatory inverters. Circular polarization-discriminatory handedness inverter is realized as a combination of half-wave plate and Bragg reflector and that of linear polarization inverter is realized as a combination of quarter-wave plate, Bragg reflector and quarter-wave plate. The zigzag microstructures of the quarter-wave plates as well as the half-wave plates and the helical structure of the Bragg reflector are fabricated by electron beam evaporation using GLAD technique and Ti@O@sub 2 material is used in this purpose. The physical thicknesses of the half and quarter-wave plates are calculated using their anisotropy. The polarization-discriminatory inverters show that the incident linear and circular polarized light becomes opposite linear and circular polarized lights with Bragg effect at output. The structural and surface morphology of this device are also investigated using scanning electron microscope (SEM).