Tapered Waveguide Design for Heat-Assisted Magnetic Recording Applications

In this paper we discuss two types of complex tapered waveguides that can be used for heat-assisted magnetic recording (HAMR) applications. HAMR is an emerging technique in the hard disk drive (HDD) industry that enables nano-scale magnetic recording. It requires the use of a laser beam to define magnetic recording features, where the size and profile of delivered optical spot is critical for this technique. In this work, we first show that traditional tapered waveguide and some reported advanced designs do not work well for the case of HAMR. Then we demonstrate with simulation results that specially designed tapered waveguides can deliver highly focused optical beam for use in HAMR systems. At the same time, the proposed waveguide structures can be realized with conventional industry top down fabrication process, which facilitates the integration of such structures with conventional magnetic head industry manufacturing at low cost.