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import matplotlib.pyplot as plt
import numpy as np
from numpy import linalg as LA
import meep as mp
n = 3.4
w = 1
r = 1
pad = 4
dpml = 2
sxy = 2 * (r + w + pad + dpml)
cell_size = mp.Vector3(sxy, sxy)
pml_layers = [mp.PML(dpml)]
nonpml_vol = mp.Volume(mp.Vector3(), size=mp.Vector3(sxy - 2 * dpml, sxy - 2 * dpml))
geometry = [
mp.Cylinder(radius=r + w, material=mp.Medium(index=n)),
mp.Cylinder(radius=r),
]
fcen = 0.118
src = [
mp.Source(mp.ContinuousSource(fcen), component=mp.Ez, center=mp.Vector3(r + 0.1)),
mp.Source(
mp.ContinuousSource(fcen),
component=mp.Ez,
center=mp.Vector3(-(r + 0.1)),
amplitude=-1,
),
]
symmetries = [mp.Mirror(mp.X, phase=-1), mp.Mirror(mp.Y, phase=+1)]
sim = mp.Simulation(
cell_size=cell_size,
geometry=geometry,
sources=src,
resolution=10,
force_complex_fields=True,
symmetries=symmetries,
boundary_layers=pml_layers,
)
num_tols = 5
tols = np.power(10, np.arange(-8.0, -8.0 - num_tols, -1.0))
ez_dat = np.zeros((122, 122, num_tols), dtype=np.complex_)
for i in range(num_tols):
sim.init_sim()
sim.solve_cw(tols[i], 10000, 10)
ez_dat[:, :, i] = sim.get_array(vol=nonpml_vol, component=mp.Ez)
err_dat = np.zeros(num_tols - 1)
for i in range(num_tols - 1):
err_dat[i] = LA.norm(ez_dat[:, :, i] - ez_dat[:, :, num_tols - 1])
plt.figure(dpi=150)
plt.loglog(tols[: num_tols - 1], err_dat, "bo-")
plt.xlabel("frequency-domain solver tolerance")
plt.ylabel("L2 norm of error in fields")
plt.show()
eps_data = sim.get_array(vol=nonpml_vol, component=mp.Dielectric)
ez_data = np.real(ez_dat[:, :, num_tols - 1])
plt.figure()
plt.imshow(eps_data.transpose(), interpolation="spline36", cmap="binary")
plt.imshow(ez_data.transpose(), interpolation="spline36", cmap="RdBu", alpha=0.9)
plt.axis("off")
plt.show()
if np.all(np.diff(err_dat) < 0):
print(
"PASSED solve_cw test: error in the fields is decreasing with increasing resolution"
)
else:
print(
"FAILED solve_cw test: error in the fields is NOT decreasing with increasing resolution"
)
sim.reset_meep()
df = 0.08
src = [
mp.Source(
mp.GaussianSource(fcen, fwidth=df), component=mp.Ez, center=mp.Vector3(r + 0.1)
),
mp.Source(
mp.GaussianSource(fcen, fwidth=df),
component=mp.Ez,
center=mp.Vector3(-(r + 0.1)),
amplitude=-1,
),
]
sim = mp.Simulation(
cell_size=mp.Vector3(sxy, sxy),
geometry=geometry,
sources=src,
resolution=10,
symmetries=symmetries,
boundary_layers=pml_layers,
)
dft_obj = sim.add_dft_fields([mp.Ez], fcen, 0, 1, where=nonpml_vol)
sim.run(until_after_sources=100)
eps_data = sim.get_array(vol=nonpml_vol, component=mp.Dielectric)
ez_data = np.real(sim.get_dft_array(dft_obj, mp.Ez, 0))
plt.figure()
plt.imshow(eps_data.transpose(), interpolation="spline36", cmap="binary")
plt.imshow(ez_data.transpose(), interpolation="spline36", cmap="RdBu", alpha=0.9)
plt.axis("off")
plt.show()
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