The Simulation Of Electric Field Enhancement Of Cone Tip

As the rapid development of human society, people has accumulated more and more knowledge. Date storage technology develops under the background of increasing knowledge, especially in the21st century, information increases obviously much faster than ever before and the existing technology cannot satisfy the big bang. So date storage technology of high density is on demand and being paid more and more attention.Firstly in this paper, we give a simple introduction of the history of date storage and then give the diffraction limit. In recent years Blu-ray disc can store about27GB date. However, because of the diffraction limit effect, even turn to purple light (the current technology can only use blue light), storage density only improves several times. Then we know the density of traditional far field optical storage cannot develop because of physical reasons. At the same time, increasing numerical aperture causes focal depth decrease, the distortion caused by eccentricity increases, so the improvement of storage density was limited. New technology must develop. At the end of this chapter, we introduce two new technologies:3d optical storage and near-field optical storage.Secondly, we introduce the surface plasma. We first introduce the discover history of surface plasma and several surface plasma modals in metal. After my introduction, we all know the principle of Tip enhancement which will be study later. At the end of this chapter we introduce several incentive methods of the surface plasma.Finally, we use finite element method to find the optimal combination of tip length and incidence angle for tip enhancement. But in our actual experiments, we can not only focus on the tip, but also focus on other related systems like recording medium. We try to bring the recording medium into our simulations and focus on the effects of medium dielectric constant of recording medium. Through a series of calculation and we draw the conclusion:when incidence wavelength is632.8nm,only the tip length is450nm and the incidence light angle is113degrees the enhancement of electric field under the tip is the largest. The enhancement of tip is even larger by the recording medium, and the shape of electric field distribution is better than before.