Simulation Of Temperature Field Distribution Of Super-RENS In Optical Magnetic Hybrid Recording

The growth of the areal density of magnetic recording and optical recording is limited because of the superparamagnetic effect and optical diffraction limit. In order to obtain higher storage density, the optical magnetic hybrid recording which combines the magnetic recording, optical recording and magneto-optical recording begins to form gradually. This technology uses a high coercivity medium and an external laser that may be used to locally reduce its value to a point where the field from the magnetic head is sufficient to switch the magnetization. The process of laser-induced local heating in this method can be achieved by using the near-field optical recording methods.The super-resolution near-filed structure (Super-RENS) is the best choose of the methods used in the near-field optical recording technology. The nano aperture of Super-RENS is formed by the nonlinear optical effect of mask layer. It has no space control and tip crushed problem in the near-field optical scanning microscope (NSOM). In this type of method, the mask layer plays an important role in the super-resolution structure.According to the multilayer structure of Super-RENS, the optical transmit model was created with optical admittance characteristic matrix, and the genetic algorithms (GA) was adopted to do the optimum design. A numerical simulation was carried out by FEMLAB to understand the forming process of the aperture as well as the propagation of laser beam. The temperature filed distribution of FePt which is the recording medium is also simulated. The simulation results showed that transmitted aperture would not be formed until the exposure power exceeded a threshold within a certain pulse time, further more, the aperture size would be increased if the power was raised. And the size of the recording mark is according to the aperture of mask layer.