FDTD simulation of various thickness PAAO with 20 nm Au film in different mediums (AoI 45 deg., s-polarization)

FDTD software: Lumerical (Ansys, version 2021 R2.3).

Structure: aluminum (Palik) substrate; 250/280/310/340/370/400 nm thickness (he) aluminum oxide (Palik) layer with 35 nm diameter (RPo) cylindrical pores with 100 nm distance (D) between the pore centers (representing porous anodized aluminum oxide - PAAO); 20 nm thickness (hA) gold (Johnson and Christy) layer. The pores extend through both PAAO and Au layers as it was observed in SEM images.

Refractive index of the surrounding medium (n): 1.0; 1.1; 1.2; 1.3; 1.32; 1.33; 1.34.

Simulation region: from 100 nm below the substrate/PAAO interface to 700 nm above gold film surface; x and y spans are equal to one period of the structure.

Mesh override region: from 30 nm below the PAAO to 30 nm above Au; 2 nm step size in each direction.

Light source: BFAST plane wave light source; 250 nm above Au film; 45° angle of incidence (ang); 300 nm – 1000 nm wavelength range; s-polarization (pol).

Monitor (frequency domain field and power): 2D Z-normal; 500 nm above Au; results are in "_reflection.txt" files.

Information in the file name: he - thickness of PAAO; pol - polarization; hA - thickness of Au film; RPo - diameter of pores; D - distance between pore centers; ang - angle of incidence; n - refractive index of surrounding medium.

Files: (1) "_reflection.txt" - lambda(nm) (first column) - wavelength in nanometers; Y (second column) - T data from the monitor above the structure. (2) "_p0.log" - log file produced by the software while running the simulation. (3) ".fsp" - Lumerical software file containing the simulation project (license required to open these files). (4) "Lumerical_Screenshots.pdf" - shows software screenshots for every object and its every property; red text is added to show which values are different for different simulations. (5) "Structure_Illustration.jpg" - a schematic of modeled structure. (6) ".jpg" - a preview of data from "_reflection.txt" files.