Kerr enhancement by SiO and AlN films sputtered on plastic substrates

It has been found that there is a remarkable difference of Kerr enhancement effect between films sputtered on glass and on plastics. SiO film does not show so clear enhancement on plastics while it does on glass. Dependence of Kerr rotation angle Θk on SiO film thickness was compared with calculated Θk for different values of refractive index n, and the decrease of n was found on plastics. Also surface roughness was observed on plastics. On the other hand, AlN film shows fairly well enhancement even on plastics as well as on glass. There is no decrease of n, and smoother surface was observed. To obtain enough enhancement, many factors should be optimized.