Development of an Air Gap Servo System for High Data Transfer Rate Near Field Optical Recording

This paper describes development of a bi-axial actuator-based air gap servo system for a near field optical recording system using a blue laser and a solid immersion lens (SIL). We first present a new pull-in procedure ensuring smooth air gap servo start-up without lens-disc collision. Furthermore, a memory-loop control technique has been employed to realize a high-speed air gap servo system guaranteeing a high data transfer rate.