AbstractTwo main ingredients of plasmonics are surface plasmon polaritons (SPP) and
localized surface plasmon resonances (LSPR) as they provide a high degree of
concentration of electromagnetic fields in the vicinity of metal surfaces, which
is well beyond that allowed by the diffraction limit of optics. Those properties
have been used in the new technique of heat assisted magnetic recording (HAMR)
to overcome an existing limit of conventional magnetic recording by utilizing a
near-field transducer (NFT). The NFT designs are based on excitation of surface
plasmons on a metal structure, which re-radiate with a subdiffraction limited
light spot confined in the near field. In this paper, we propose a novel
“droplet”-shaped NFT, which takes full advantage of a recenltly proposed
Mach–Zehnder Interferometer (MZI), a coupling arrangement that allows optimal
coupling of light to the transducer. The droplet design ensures better impedance
match with the recording media and, consequently, better coupling of power. The
droplet design results in very high enhancement of the electric field and allows
the confinement of light in a spot size much smaller than the present stateof-
the-art lollipop transducer.
Novel droplet near-field transducer for heat-assisted magnetic recording
