stackfield - Script command – Lumerical Support

FDTD MODE DGTD CHARGE HEAT FEEM INTERCONNECT

Calculates the fields within a multilayer stack illuminated from below by a plane wave using the analytic transfer matrix method. This function returns the E and H fields (Es, Ep, Hs, Hp). All results are returned in a single dataset as a function of frequency, incidence angle and location in the stack (z).

Syntax

Description

field = stackfield(n,d,f);

The arguments for a stack with Nlayers are as follows.

n: Refractive index of each layer. Size can be

Nlayers: isotropic and non-dispersive
Nlayers x Nfreq: isotropic and dispersive
Nlayers x 3: anisotropic and non-dispersive
Nlayers x Nfreq x 3: anisotropic and dispersive materials are involved.
NOTE: Only birefringence in z (nx=ny≠nz) is supported. The commands will give an error unless nx=ny.

d: Thickness of each layer. Size is Nlayers.

f: Frequency vector with a length of Nfreq.

field = stackfield(n,d,f,theta,res);

theta: Angle vector, in degrees. Optional, default is 0.

res: resolution in the field result returned. Optional, default is 1000.

field = stackfield(n,d,f,theta,res,min,max);

min/max: the min/max position where the user wishes to compute the field. 0 corresponds to the bottom of the stack. Optional, default is the span of the multilayer stack.

Example

Calculate the field distribution of a 5 layer stack.

f = linspace(c/400e-9, c/1000e-9,100); # frequency vector
theta = 0:1:45; # angle vector
d = [0; 200e-9; 300e-9; 400e-9; 0]; # 5 layers (including air on top and bottom)
nf = length(f);
nd = length(d);

# refractive indices for non-dispersive materials
n1 = [1; 1.5; 2.5; 1.5; 1]; 

# refractive indices for dispersive materials
n2 = matrix(nd,nf);
n2(1,1:nf) = 1; # air
n2(2,1:nf) = getfdtdindex("SiO2 (Glass) - Palik",f,min(f),max(f));
n2(3,1:nf) = getfdtdindex("Si (Silicon) - Palik",f,min(f),max(f));
n2(4,1:nf) = getfdtdindex("SiO2 (Glass) - Palik",f,min(f),max(f));
n2(5,1:nf) = 1; # air

field1 = stackfield(n1,d,f); # non-dispersive index data, and theta=0
field2 = stackfield(n2,d,f,theta); # dispersive data index data, and theta from 0 to 45 deg

visualize(field1);
visualize(field2);

Here's an example for a birefringent slab in air:

N_layers = 3;
Nfreqs = 100;
res = 1000;
n = matrix(N_layers, Nfreqs, 3);

n(1, :, :) = 1;   # air
n(2, :, 1) = 2.1; # nx
n(2, :, 2) = 2.1; # ny
n(2, :, 3) = 2.5; # nz
n(3, :, :) = 1;   # air

d = [0; 1e-6; 0]; # air/ birefringent slab / air
f = linspace(c/1e-6, c/1.5e-6, Nfreqs);
theta = 0:1:45;

field = stackfield(n,d,f,theta,res); 

visualize(field);

stackfield - Script command

Associated files

Related articles