Fuquan Wu

Microstructure and optical properties of Cu∕Al2O3 nanoarray composite structure

Cu∕Al2O3 nanoarray composite structure was obtained by alternating-current electrodeposition Cu into the pores of anodic alumina. The ordered wire-grid structure of Cu nanowires formed along a preferential direction, typically 20nm in diameter, possesses a face-centered-cubic crystalline structure. Optical properties of Cu∕Al2O3 were investigated in detail. An apparent resonance absorption peak near 560nm was observed, and with the increasing amount of electrodeposition Cu, the blueshift of the peak and the redshift of the absorption band edge were observed. Experimental results also indicate that Cu nanowires have good transmittance characteristic in near-IR wave band and do not exhibit obvious absorption action in mid-IR wave band; in the range of 800–2000nm, Cu∕Al2O3 present a good polarization property, and with the increase of electrodeposition time, the polarization increases.

A unit structure Rochon prism based on the extraordinary refraction of uniaxial birefringent crystals.

Based on the Fermats principle, the universal theory of refraction and reflection of extraordinary rays (e-rays) in the uniaxial crystal is formulated. Using this theory, a new unit structure prism is designed, and its properties are studied. Based on the theoretical results, such a prism is achieved experimentally by using the Iceland crystal. In both theoretical and experimental studies, this new prism shows excellent polarization splitting performances such as big and adjustable splitting angle, comparing to the conventional Rochon prism. For the sample prism with the optical axis angle of 45°, the splitting angle reaches 19.8°in the normal incidence, and the maximum splitting angle reaches 28.44° while the incidence angle is -4°.