Enhancement of near-field light generated by metal nanodot on semiconductor substrate for heat-assisted magnetic recording heat source

In the novel device for a heat-assisted magnetic recording heat source where a metal nanodot is formed on a semiconductor substrate, the possibility of enhancing the near-field light by selecting suitable combinations of the materials for the metal nanodot and semiconductor substrate was investigated through a numerical simulation. It was found that the enhancement factor of the light intensity at a certain resonance wavelength for the light polarized perpendicularly to the surface of the substrate can be improved by two methods. One is to use an alloy as the material for the metal nanodot and the other is to use a ternary mixed crystal as the material for the semiconductor substrate. Design examples were shown for both methods. The ratio of each element in the alloy or ternary mixed crystal should be determined considering the balance between the enhancement factor and some other factors such as stability, availability, and convenience. (C) 2015 The Japan Society of Applied Physics