This page explains how to simulate plasmon antenna as a near field transducer for HAMR.
The figure below shows the structure we're simulating here. A focused light with a wavelength 650nm coupled into a waveguide and the light travels down to the plasmon antenna (PA) which is considered to be a triangular silver nanoparticle. Due to the excitation of localized surface plasmon, strongly localized light is generated at the tip of the PA and this localized enhanced field can provide a heat into a nanoscale region in Data Layer (DL).
In this simulation, FDTD is used and the optical constant in the simulation is summarized in the table below.
The figures below show the electric field profile on the surface of the DL where the electric field is enhanced at the tip of the particle. The data is recorded in a monitor named "DL_surface_field". An enhanced field is observed below the tip of PA (y = 0.25).
To model thin layer such as DL and SUL, override mesh objects should be used. In the attached file plasmon_antenna.fsp, mesh override objects are added but disabled for faster simulation. The result without override mesh objects is like the figure below.
If you want to get precise results, you nee to enable override mesh objects and set the mesh size small enough depending on your desirable accuracy.
K. Takano, E. Jin, E. Schreck, J. Smyth, and M. Dovek, "Automatic Design Optimization of Plasmon Antenna for Thermally Assisted Magnetic Recording," IEEE Trans. Magn., vol. 45, no. 1, pp. 3604–3607 (2008).
K. Takano, E. Jin, T. Maletzky, E. Schreck, and M. Dovek, "Optical Design Challenges of Thermally Assisted Magnetic Recording Heads," IEEE Trans. Magn., vol. 46, pp. 744–7507 (2010).