Abstract The performance of many optical glass elements depends on the structure of the surface. The high refractive index of flint glass is advantageous in con structing some optical elements (lenses, prisms, beam splitters, …). Also, high achromaticity and size reduction in oblique incidence TIR (total internal ref lection) phase retarders require high-index glass. The present work is inter ested in studying the optical properties of the thin surface layer formed on TIR rhomb retarder at different wavelengths to indicate the extent to which this surface layer affects the performance of this TIR rhomb retarder and show how to overcome this effect.

Abstract CNT-added surface treatment (CAST) is a newly developed technology that incorporates single-walled carbon nanotubes (SWCNTs) into a metal surface through alternate current electrolysis using a dispersion of SWCNTs in an alkaline aqueous solution. We apply this method to Al-plates and characterize their surface morphology and components through scanning electron micro scopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. After CAST processing, pro trusion structures of Al-oxide containing SWCNTs are formed on the surface of the Al-plate, and the surface morphology differs significantly from that of the surface of Al films treated through conventional anodic oxidation. The height and spacing of the protrusion structures formed on the surface of the CAST-treated Al-plates are 100 - 200 nm and 50 - 100 nm, respectively. In addition, we investigate the formation mechanism of the protrusion structure by applying a DC voltage between the working electrode (Al-plate) and a counter electrode immersed in a dispersion of SWCNTs in an alkaline aqueous solution. Comparing the Al-plate surface after treatment under both current directions, we propose a model for the formation process of protru sion structures containing SWCNTs based on catalyst surface etchi .