Simulation on parameter optimization of semiconductor ring resonator with nano-antenna for heat-assisted magnetic recording device

Abstract

Heat-assisted magnetic recording (HAMR) is a promising technology with high recording density. The authors’ group has proposed a novel device for HAMR, in which a metal nano-antenna as a near-field transducer is attached to a semiconductor ring resonator as a light source. The ring resonator oscillation should be stable to generate steady near-field light with proper energy density to heat the recording medium. To improve the device performance, the dependence of resonance frequency, electric field intensity distribution, and normalized energy density at the tip of the nano-antenna on ring width and ring size was numerically simulated. When the ring width became wider, the resonance frequency and normalized energy density were more stable and operable, which leads to wide manufacturing tolerance. Although unnecessary solutions with higher radial mode order appeared in this condition, they are easy to control. When the ring size became smaller, the frequency interval between adjacent modes became wider, which leads to the stability of laser oscillation. Moreover, the normalized energy density was increased. As a result, the ring resonator obtains its optimal result with a wide width and an adequately small size.