Near-field spectrum • terms

Objective

This example illustrates the calculation of near-field calculations for multiple wavelengths. The structure consists of a chiral tetramer of gold spheres in water. The wavelength is varied from 500 to 700 nm, and we map the electric field intensity and normalised local degree of chirality in the xy plane around the structure, which is illuminated with linear polarisation at 45 degrees in the xy plane and wavevector along z. Note that a small value of Nmax is used to keep the calculation time short; for accurate results a larger value should be used.

This simulation uses the following input file

ModeAndScheme 1 3
Wavelength 500 700 40
MultipoleCutoff 4
Medium 1.7689
Incidence 0.7853982 0 0 1 # pi/4 linear

OutputFormat HDF5 map
SpacePoints -40 100 100 -40 100 100 0 0 0 0 0 0 
MapQuantity 2 E C

Scatterers 4
Au 0 65 0 30
Au 0 0 0 30
Au 65 0 0 30
Au 65 0 65 30

The results contain the near-field data for all wavelengths in long format

        group            name       otype dclass        dim
0           /      Near-Field   H5I_GROUP                  
1 /Near-Field      Gridpoints H5I_DATASET  FLOAT  10201 x 3
2 /Near-Field      Incidences H5I_DATASET  FLOAT      1 x 4
3 /Near-Field     Wavelengths H5I_DATASET  FLOAT         41
4 /Near-Field           map_E H5I_DATASET  FLOAT 418241 x 7
5 /Near-Field normalised_ldoc H5I_DATASET  FLOAT 418241 x 5

Intensity

LDOC

Animation

The same data can also be visualised as an animation by mapping the wavelength to time

Last run: 05 December, 2023