[examples/fdfd] split fdfd example into two files

This commit is contained in:
jan 2025-12-10 21:14:34 -08:00
parent d4f1008c5c
commit fb3bef23bf
2 changed files with 135 additions and 121 deletions

103
examples/fdfd0.py Normal file
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@ -0,0 +1,103 @@
import numpy
from numpy.linalg import norm
from matplotlib import pyplot, colors
import logging
import meanas
from meanas import fdtd
from meanas.fdmath import vec, unvec
from meanas.fdfd import waveguide_3d, functional, scpml, operators
from meanas.fdfd.solvers import generic as generic_solver
import gridlock
logging.basicConfig(level=logging.DEBUG)
logging.getLogger('matplotlib').setLevel(logging.WARNING)
__author__ = 'Jan Petykiewicz'
def pcolor(ax, v) -> None:
mappable = ax.pcolor(v, cmap='seismic', norm=colors.CenteredNorm())
ax.axis('equal')
ax.get_figure().colorbar(mappable)
def test0(solver=generic_solver):
dx = 50 # discretization (nm/cell)
pml_thickness = 10 # (number of cells)
wl = 1550 # Excitation wavelength
omega = 2 * numpy.pi / wl
# Device design parameters
radii = (1, 0.6)
th = 220
center = [0, 0, 0]
# refractive indices
n_ring = numpy.sqrt(12.6) # ~Si
n_air = 4.0 # air
# Half-dimensions of the simulation grid
xyz_max = numpy.array([1.2, 1.2, 0.3]) * 1000 + pml_thickness * dx
# Coordinates of the edges of the cells.
half_edge_coords = [numpy.arange(dx/2, m + dx, step=dx) for m in xyz_max]
edge_coords = [numpy.hstack((-h[::-1], h)) for h in half_edge_coords]
# #### Create the grid, mask, and draw the device ####
grid = gridlock.Grid(edge_coords)
epsilon = grid.allocate(n_air**2, dtype=numpy.float32)
grid.draw_cylinder(
epsilon,
h = dict(axis='z', center=center[2], span=th),
radius = max(radii),
center2d = center[:2],
foreground = n_ring ** 2,
num_points = 24,
)
grid.draw_cylinder(
epsilon,
h = dict(axis='z', center=center[2], span=th * 1.1),
radius = min(radii),
center2d = center[:2],
foreground = n_air ** 2,
num_points = 24,
)
dxes = [grid.dxyz, grid.autoshifted_dxyz()]
for a in (0, 1, 2):
for p in (-1, 1):
dxes = meanas.fdfd.scpml.stretch_with_scpml(dxes, axis=a, polarity=p, omega=omega,
thickness=pml_thickness)
J = [numpy.zeros_like(epsilon[0], dtype=complex) for _ in range(3)]
J[1][15, grid.shape[1]//2, grid.shape[2]//2] = 1
#
# Solve!
#
sim_args = dict(
omega = omega,
dxes = dxes,
epsilon = vec(epsilon),
)
x = solver(J=vec(J), **sim_args)
A = operators.e_full(omega, dxes, vec(epsilon)).tocsr()
b = -1j * omega * vec(J)
print('Norm of the residual is ', norm(A @ x - b) / norm(b))
E = unvec(x, grid.shape)
#
# Plot results
#
grid.visualize_slice(E.real, plane=dict(z=0), which_shifts=1, pcolormesh_args=dict(norm=colors.CenteredNorm(), cmap='bwr'))
if __name__ == '__main__':
test0()

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@ -1,6 +1,8 @@
import importlib
import numpy
from numpy.linalg import norm
from matplotlib import pyplot, colors
import logging
import meanas
from meanas import fdtd
@ -10,9 +12,6 @@ from meanas.fdfd.solvers import generic as generic_solver
import gridlock
from matplotlib import pyplot
import logging
logging.basicConfig(level=logging.DEBUG)
logging.getLogger('matplotlib').setLevel(logging.WARNING)
@ -20,86 +19,6 @@ logging.getLogger('matplotlib').setLevel(logging.WARNING)
__author__ = 'Jan Petykiewicz'
def test0(solver=generic_solver):
dx = 50 # discretization (nm/cell)
pml_thickness = 10 # (number of cells)
wl = 1550 # Excitation wavelength
omega = 2 * numpy.pi / wl
# Device design parameters
radii = (1, 0.6)
th = 220
center = [0, 0, 0]
# refractive indices
n_ring = numpy.sqrt(12.6) # ~Si
n_air = 4.0 # air
# Half-dimensions of the simulation grid
xyz_max = numpy.array([1.2, 1.2, 0.3]) * 1000 + pml_thickness * dx
# Coordinates of the edges of the cells.
half_edge_coords = [numpy.arange(dx/2, m + dx, step=dx) for m in xyz_max]
edge_coords = [numpy.hstack((-h[::-1], h)) for h in half_edge_coords]
# #### Create the grid, mask, and draw the device ####
grid = gridlock.Grid(edge_coords)
epsilon = grid.allocate(n_air**2, dtype=numpy.float32)
grid.draw_cylinder(
epsilon,
surface_normal=2,
center=center,
radius=max(radii),
thickness=th,
foreground=n_ring**2,
num_points=24,
)
grid.draw_cylinder(
epsilon,
surface_normal=2,
center=center,
radius=min(radii),
thickness=th*1.1,
foreground=n_air ** 2,
num_points=24,
)
dxes = [grid.dxyz, grid.autoshifted_dxyz()]
for a in (0, 1, 2):
for p in (-1, 1):
dxes = meanas.fdfd.scpml.stretch_with_scpml(dxes, axis=a, polarity=p, omega=omega,
thickness=pml_thickness)
J = [numpy.zeros_like(epsilon[0], dtype=complex) for _ in range(3)]
J[1][15, grid.shape[1]//2, grid.shape[2]//2] = 1
#
# Solve!
#
sim_args = {
'omega': omega,
'dxes': dxes,
'epsilon': vec(epsilon),
}
x = solver(J=vec(J), **sim_args)
A = operators.e_full(omega, dxes, vec(epsilon)).tocsr()
b = -1j * omega * vec(J)
print('Norm of the residual is ', norm(A @ x - b))
E = unvec(x, grid.shape)
#
# Plot results
#
pyplot.figure()
pyplot.pcolor(numpy.real(E[1][:, :, grid.shape[2]//2]), cmap='seismic')
pyplot.axis('equal')
pyplot.show()
def test1(solver=generic_solver):
dx = 40 # discretization (nm/cell)
pml_thickness = 10 # (number of cells)
@ -126,7 +45,7 @@ def test1(solver=generic_solver):
# #### Create the grid and draw the device ####
grid = gridlock.Grid(edge_coords)
epsilon = grid.allocate(n_air**2, dtype=numpy.float32)
grid.draw_cuboid(epsilon, center=center, dimensions=[8e3, w, th], foreground=n_wg**2)
grid.draw_cuboid(epsilon, x=dict(center=0, span=8e3), y=dict(center=0, span=w), z=dict(center=0, span=th), foreground=n_wg**2)
dxes = [grid.dxyz, grid.autoshifted_dxyz()]
for a in (0, 1, 2):
@ -160,17 +79,9 @@ def test1(solver=generic_solver):
# grid.draw_cuboid(pmcg, center=[700, 0, 0], dimensions=[80, 1e8, 1e8], eps=1)
# grid.visualize_isosurface(pmcg)
def pcolor(v) -> None:
vmax = numpy.max(numpy.abs(v))
pyplot.pcolor(v, cmap='seismic', vmin=-vmax, vmax=vmax)
pyplot.axis('equal')
pyplot.colorbar()
ss = (1, slice(None), J.shape[2]//2+6, slice(None))
# pyplot.figure()
# pcolor(J3[ss].T.imag)
# pyplot.figure()
# pcolor((numpy.abs(J3).sum(axis=2).sum(axis=0) > 0).astype(float).T)
grid.visualize_slice(J.imag, plane=dict(y=6*dx), which_shifts=1, pcolormesh_args=dict(norm=colors.CenteredNorm(), cmap='bwr'))
fig, ax = pyplot.subplots()
ax.pcolormesh((numpy.abs(J).sum(axis=2).sum(axis=0) > 0).astype(float).T, cmap='hot')
pyplot.show(block=True)
#
@ -196,16 +107,14 @@ def test1(solver=generic_solver):
# Plot results
#
center = grid.pos2ind([0, 0, 0], None).astype(int)
pyplot.figure()
pyplot.subplot(2, 2, 1)
pcolor(numpy.real(E[1][center[0], :, :]).T)
pyplot.subplot(2, 2, 2)
pyplot.plot(numpy.log10(numpy.abs(E[1][:, center[1], center[2]]) + 1e-10))
pyplot.grid(alpha=0.6)
pyplot.ylabel('log10 of field')
pyplot.subplot(2, 2, 3)
pcolor(numpy.real(E[1][:, :, center[2]]).T)
pyplot.subplot(2, 2, 4)
fig, axes = pyplot.subplots(2, 2)
grid.visualize_slice(E.real, plane=dict(x=0), which_shifts=1, ax=axes[0, 0], finalize=False, pcolormesh_args=dict(norm=colors.CenteredNorm(), cmap='bwr'))
grid.visualize_slice(E.real, plane=dict(z=0), which_shifts=1, ax=axes[0, 1], finalize=False, pcolormesh_args=dict(norm=colors.CenteredNorm(), cmap='bwr'))
# pcolor(axes[0, 0], numpy.real(E[1][center[0], :, :]).T)
# pcolor(axes[0, 1], numpy.real(E[1][:, :, center[2]]).T)
axes[1, 0].plot(numpy.log10(numpy.abs(E[1][:, center[1], center[2]]) + 1e-10))
axes[1, 0].grid(alpha=0.6)
axes[1, 0].set_ylabel('log10 of field')
def poyntings(E):
H = functional.e2h(omega, dxes)(E)
@ -219,34 +128,35 @@ def test1(solver=generic_solver):
return s0, s1, s2
s0x, s1x, s2x = poyntings(E)
pyplot.plot(s0x[0].sum(axis=2).sum(axis=1), label='s0', marker='.')
pyplot.plot(s1x[0].sum(axis=2).sum(axis=1), label='s1', marker='.')
pyplot.plot(s2x[0].sum(axis=2).sum(axis=1), label='s2', marker='.')
pyplot.plot(E[1][:, center[1], center[2]].real.T, label='Ey', marker='x')
pyplot.grid(alpha=0.6)
pyplot.legend()
pyplot.show()
ax = axes[1, 1]
ax.plot(s0x[0].sum(axis=2).sum(axis=1), label='s0', marker='.')
ax.plot(s1x[0].sum(axis=2).sum(axis=1), label='s1', marker='.')
ax.plot(s2x[0].sum(axis=2).sum(axis=1), label='s2', marker='.')
ax.plot(E[1][:, center[1], center[2]].real.T, label='Ey', marker='x')
ax.grid(alpha=0.6)
ax.legend()
p_in = (-E * J.conj()).sum() / 2 * (dx * dx * dx)
print(f'{p_in=}')
q = []
for i in range(-5, 30):
e_ovl_rolled = numpy.roll(e_overlap, i, axis=1)
q += [numpy.abs(vec(E) @ vec(e_ovl_rolled).conj())]
pyplot.figure()
pyplot.plot(q, marker='.')
pyplot.grid(alpha=0.6)
pyplot.title('Overlap with mode')
pyplot.show()
q += [numpy.abs(vec(E).conj() @ vec(e_ovl_rolled))]
fig, ax = pyplot.subplots()
ax.plot(q, marker='.')
ax.grid(alpha=0.6)
ax.set_title('Overlap with mode')
print('Average overlap with mode:', sum(q[8:32])/len(q[8:32]))
pyplot.show(block=True)
def module_available(name):
return importlib.util.find_spec(name) is not None
if __name__ == '__main__':
#test0()
# test1()
if module_available('opencl_fdfd'):
from opencl_fdfd import cg_solver as opencl_solver
test1(opencl_solver)
@ -257,3 +167,4 @@ if __name__ == '__main__':
# test1(magma_solver)
else:
test1()