R&D: Simulation on Non-Axisymmetric Ring Resonator with Nano-Antenna for HAMR

Japanese Journal of Applied Physics has published an article written by Jinghan Chen, Information Electronics, Graduate School of Engineering, Fukuoka Institute of Technology, Fukuoka 811-0295, Japan, and School of Science, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, People’s Republic of China, Ryuichi Katayama, Information Electronics, Graduate School of Engineering, Fukuoka Institute of Technology, Fukuoka 811-0295, Japan, and Satoshi Sugiura, InnovaStella, Inc., Bunkyo-ku, Tokyo 113-0032, Japan.

Abstract: “Heat-assisted magnetic recording is a technology to improve recording density of hard disk drives. The authors’ group previously proposed a device, in which a Au nano-antenna as a near-field transducer was attached to a GaAs ring resonator as a light source. The ring resonator should stably oscillate with a single mode to generate near-field light at the tip of the nano-antenna with sufficient energy density. A non-axisymmetric ring resonator structure was proposed this time to improve the energy density and laser oscillation stability. When the decenter between the inner and outer circles of the ring resonator increased, the resonance frequency increased and eigenmodes with higher radial mode order disappeared, which leads to stable laser oscillation. Moreover, when the decenter was 200 or 250 nm, the normalized energy density at the tip of nano-antenna increased 1.2–2.4 times compared with an axisymmetric ring resonator structure while keeping the quality factor to more than 5000.“