Investigation of the Dynamic Characteristics of Light Delivery for Thermal Assisted Magnetic Recording

Several new technologies have recently been proposed for high areal density greater than 5 Tb/in² as next generation storage devices. Among these technologies is thermal assisted magnetic recording (TAMR). However, there are several dynamic and realistic problems associated with the current method of TAMR light delivery that must be resolved. In this paper, we investigate and discuss the dynamic characteristics for two kinds of light delivery systems using experimental and simulated results. We concluded that the optical fiber TAMR light delivery system had higher vertical and pitch stiffness. This could result in higher flying height modulation (FHM) on the disk surface and reduced TD-TO performance. Furthermore, since the optical fiber TAMR light delivery system has a lower positive pitch angle during unloading process, as soon as the air bearing disappears after the limiter is engaged, the contact possibility between the slider and the disk increases in unloading process. In addition, for the mounted laser diode (LD) TAMR light delivery system, we constructed a thermal-structural coupling finite element (FE) model of the entire TAMR system and simulated the thermal distribution and structural expansion according to temperature distribution. The results showed that the thermal problem was caused by heat produced by the LD, which can affect the head disk interface (HDI) problem in high areal density.