Dark-field scattering spectroscopy to study transducer stability for heat-assisted magnetic recording

Thermal stability of optical near field transducers is an important issue for heat-assisted magnetic recording (HAMR), which affects HAMR system lifetime. In this paper, dark-field scattering spectroscopy was used to study the stability of nanometer-scaled Au lollipop transducers that were subjected to thermal annealing. Variation in relative peak intensity and red-shifting in peak position can be observed in scattering spectra for transducer after annealing. Based on the optical characterizations on Au thin films and calculations of Mie scattering by finite-difference time domain simulations, the measured changes in transducer scattering properties can reflect annealing-induced variations in optical properties and dimensional feature size for the Au lollipop transducer. Dark-field scattering spectroscopy can be a promising method to examine HAMR near field transducer thermal stability. (c) 2015 AIP Publishing LLC.