A study of near field transducer performance and deterioration from local surface plasmon resonance in heat-assisted magnetic recording system

The effects of enhanced field intensity by local surface plasmon resonance (LSPR) on the performance of lollipop and C near field transducers (NFTs) for the heat-assisted magnetic recording (HAMR) system are demonstrated using 2D simulation. The field enhancement is clearly achieved using the transverse magnetic (TM) mode. It is found that the coupling efficiency induced in the medium by the lollipop NFT increases inversely proportional with the peg width. A similar characteristic is observed between the peak field intensity across the C aperture and its ridge width. By assuming a uniform geometry, a continuous mode emission shows a tendency to physically deteriorate and thus its performance over time, suggesting the pulsed emission as a better incident mode for the HAMR light delivery.