Improvement of near-field optical storage system with an artificial negative index film

We report a new method of enhancing the intensity of spot and improving the air-gap width of a near-field optical storage system with a real artificial negative index film (NIF). This method is based on surface plasmas excited by NIF combining a polymer film. In 2004, Liu and He proposed a near-field SIL optical storage system utilizing a negative index material [1]. In this paper, we develop the concept of the near-field optical storage using a NIF introduced by Liu and He and propose a new near-field solid immersion lens (SIL) optical recording system. Our method is based on the surface plasmas (SP) excited by a NIF-polymer composite nano-layer which is attached on the plane surface of the SIL. An experimentally-fabricated negative index material comprising silver nanorods [2] is chosen as the NIF and the refractive indices mismatching effect is considered in our simulations. The proposed system may be much more close to an actual near-field optical recording system. Numerical results based on the simple vector diffraction theory show that the present system can reduce energy loss markedly and substantially increase the gap´s width of the near-field optical storage system with a SIL.