Enhancement of Kerr rotation with amorphous Si film

The enhancemant of the Kerr rotation angle with amorphous silicon film was investigated. Doping oxygen, nitrogen and carbon as impurity in a-Si films, the absorptance at the semiconductor laser wavelength becomes almost zero keeping high refractive index. With the a-Si film containing the impurities on magnetic film, large enhancement effect is achieved than that of dielectric film. With a-Si:24at%O films, θk becomes a large value of 80 min comparing with 25 min of Gd-Tb-Fe-Co single layer film. The was improved 2 times higher than that of single layer film.