1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
|
"""Demonstration of launching a planewave source at oblique incidence.
tutorial reference:
https://meep.readthedocs.io/en/latest/Python_Tutorials/Eigenmode_Source/#planewaves-in-homogeneous-media
"""
import matplotlib.pyplot as plt
import meep as mp
import numpy as np
mp.verbosity(2)
resolution_um = 50
pml_um = 2.0
size_um = 10.0
cell_size = mp.Vector3(size_um + 2 * pml_um, size_um, 0)
pml_layers = [mp.PML(thickness=pml_um, direction=mp.X)]
# Incident angle of planewave. 0 is +x with rotation in
# counter clockwise (CCW) direction around z axis.
incident_angle = np.radians(40.0)
wavelength_um = 1.0
frequency = 1 / wavelength_um
n_mat = 1.5 # refractive index of homogeneous material
default_material = mp.Medium(index=n_mat)
k_point = mp.Vector3(n_mat * frequency, 0, 0).rotate(
mp.Vector3(0, 0, 1), incident_angle
)
if incident_angle == 0:
direction = mp.AUTOMATIC
eig_parity = mp.EVEN_Y + mp.ODD_Z
symmetries = [mp.Mirror(mp.Y)]
eig_vol = None
else:
direction = mp.NO_DIRECTION
eig_parity = mp.ODD_Z
symmetries = []
eig_vol = mp.Volume(center=mp.Vector3(), size=mp.Vector3(0, 1 / resolution_um, 0))
sources = [
mp.EigenModeSource(
src=mp.ContinuousSource(frequency),
center=mp.Vector3(),
size=mp.Vector3(0, size_um, 0),
direction=direction,
eig_kpoint=k_point,
eig_band=1,
eig_parity=eig_parity,
eig_vol=eig_vol,
)
]
sim = mp.Simulation(
cell_size=cell_size,
resolution=resolution_um,
boundary_layers=pml_layers,
sources=sources,
k_point=k_point,
default_material=default_material,
symmetries=symmetries,
)
sim.run(until=23.56)
output_plane = mp.Volume(center=mp.Vector3(), size=mp.Vector3(size_um, size_um, 0))
fig, ax = plt.subplots()
sim.plot2D(fields=mp.Ez, output_plane=output_plane, ax=ax)
fig.savefig("planewave_source.png", bbox_inches="tight")
|
