Multilayer configurations with plasmonic transducers near magnetic layers

Official URL: http://risc01.sabanciuniv.edu/record=b1589554 (Table of Contents)

Magnetic information storage technology has been one of the main technologies that requires a continuous growth due to the need for storing larger amount of data in everyday life. Accordingly, magnetic hard disk drive industry depends on continually increasing areal density. However, historically, specific physical limitations hinder this technology to continually grow. Heat-assisted magnetic recording (HAMR) is an emerging technology that has increased the areal density of conventional recording techniques for hard disc drives. In HAMR, localized optical spots that are produced by integrated heads are utilized to heat the magnetic medium during the recording process. Integrated heads have enabled this increase through localized heating of the recording media during the recording process. In this thesis, HAMR integrated heads are investigated that are modeled as multilayer configurations with plasmonic films near magnetic films. Multilayer configurations are investigated that minimize radiative and load-induced losses. It is shown that a higher electric field intensity enhancement can be obtained by minimizing radiative and load-induced losses. In order to protect the plasmonic transducer from the load-induced damping effect of the magnetic write head, a novel planarly modeled HAMR head is introduced. By engineering the field gradients in the head, optimum configurations are specified that yield higher field gradient regions in the down-track direction. The planarly layered head is utilized to design a plasmonic planar solid immersion mirror, which is theoretically and experimentally demonstrated to produce intense and localized optical spots beyond the diffraction-limit. This thesis also demonstrates multilayered surface plasmons resonance sensors with lossy samples that can provide high quality resonances. Surface plasmon resonance sensors operate generally with lossless samples or lossy thin-films. It is demonstrated that surface plasmon resonances can be recovered back when they operate with thicklossy samples.