Simulation of simultaneous tracking/data signal detection using novel aperture-mounted surface recording head

Recently, near-field surface recording based on near-field optical principles has been vigorously studied for higher data storage density. In near-field optics which utilizes an aperture, in addition to the high spatial resolution property, there is another characteristic that the shape of the optical spot can be arbitrarily controlled by the aperture configuration, and its application to various technologies in the optical disk drive is possible. From this perspective, we propose a novel tracking method utilizing an asymmetric configured aperture head which could provide continuous signal of readout data and tracking error simultaneously, and analyze its data read-out and tracking detection performance through the three-dimensional finite-difference time-domain (3D-FDTD) method. Our simulations reveal that this novel tracking head has sufficient data readout performance and high tracking sensitivity, and has the potential to readout both a data signal and a tracking signal simultaneously.