def test_swe2pwe():
ex, ey, ez = swe.electric_field(x, y, z)
pwe_up, pwe_down = fldex.swe_to_pwe_conversion(swe, k_parallel=kp, azimuthal_angles=a, layer_system=layer_system)
ex2, ey2, ez2 = pwe_up.electric_field(x, y, z)
err2 = abs(ex - ex2) ** 2 + abs(ey - ey2) ** 2 + abs(ez - ez2) ** 2
norme2 = abs(ex) ** 2 + abs(ey) ** 2 + abs(ez) ** 2
print('relative error:', np.sqrt(err2 / norme2))
assert np.sqrt(err2 / norme2) < 5e-3
def piecewise_field_expansion(self,
layer_system,
include_direct_field=True,
include_layer_response=True):
"""Compute a piecewise field expansion of the dipole field.
Args:
layer_system (smuthi.layer.LayerSystem): stratified medium
include_direct_field (bool): if True (default), the direct dipole field is included.
otherwise, only the layer response of the dipole field is
returned.
include_layer_response (bool): if True (default), the layer response of the dipole field is
included. otherwise, only the direct dipole field is
returned.
Returns:
smuthi.field_expansion.PiecewiseWaveExpansion object
"""
pfe = fldex.PiecewiseFieldExpansion()
if include_direct_field:
pfe.expansion_list.append(
self.outgoing_spherical_wave_expansion(layer_system))
if include_layer_response:
for i in range(layer_system.number_of_layers()):
# layer response as plane wave expansions
pwe_up, pwe_down = fldex.swe_to_pwe_conversion(
swe=self.outgoing_spherical_wave_expansion(layer_system),
k_parallel=self.k_parallel,
azimuthal_angles=self.azimuthal_angles,
layer_system=layer_system,
layer_number=i,
layer_system_mediated=True)
if i > 0:
pfe.expansion_list.append(pwe_up)
if i < layer_system.number_of_layers() - 1:
pfe.expansion_list.append(pwe_down)
return pfe
def scattered_field_pwe(vacuum_wavelength,
particle_list,
layer_system,
layer_number,
k_parallel='default',
azimuthal_angles='default',
include_direct=True,
include_layer_response=True):
"""Calculate the plane wave expansion of the scattered field of a set of particles.
Args:
vacuum_wavelength (float): Vacuum wavelength (length unit)
particle_list (list): List of Particle objects
layer_system (smuthi.layers.LayerSystem): Stratified medium
layer_number (int): Layer number in which the plane wave expansion should be valid
k_parallel (numpy.ndarray or str): in-plane wavenumbers array.
if 'default', use smuthi.coordinates.default_k_parallel
azimuthal_angles (numpy.ndarray or str): azimuthal angles array
if 'default', use smuthi.coordinates.default_azimuthal_angles
include_direct (bool): If True, include the direct scattered field
include_layer_response (bool): If True, include the layer system response
Returns:
A tuple of PlaneWaveExpansion objects for upgoing and downgoing waves.
"""
sys.stdout.write(
'Evaluating scattered field plane wave expansion in layer number %i ...\n'
% layer_number)
sys.stdout.flush()
omega = coord.angular_frequency(vacuum_wavelength)
k = omega * layer_system.refractive_indices[layer_number]
z = layer_system.reference_z(layer_number)
vb = (layer_system.lower_zlimit(layer_number),
layer_system.upper_zlimit(layer_number))
pwe_up = fldex.PlaneWaveExpansion(k=k,
k_parallel=k_parallel,
azimuthal_angles=azimuthal_angles,
kind='upgoing',
reference_point=[0, 0, z],
lower_z=vb[0],
upper_z=vb[1])
pwe_down = fldex.PlaneWaveExpansion(k=k,
k_parallel=k_parallel,
azimuthal_angles=azimuthal_angles,
kind='downgoing',
reference_point=[0, 0, z],
lower_z=vb[0],
upper_z=vb[1])
for iS, particle in enumerate(
tqdm(particle_list,
desc='Scatt. field pwe ',
file=sys.stdout,
bar_format='{l_bar}{bar}| elapsed: {elapsed} '
'remaining: {remaining}')):
i_iS = layer_system.layer_number(particle.position[2])
# direct contribution
if i_iS == layer_number and include_direct:
pu, pd = fldex.swe_to_pwe_conversion(
swe=particle.scattered_field,
k_parallel=k_parallel,
azimuthal_angles=azimuthal_angles,
layer_system=layer_system)
pwe_up = pwe_up + pu
pwe_down = pwe_down + pd
# layer mediated contribution
if include_layer_response:
pu, pd = fldex.swe_to_pwe_conversion(
swe=particle.scattered_field,
k_parallel=k_parallel,
azimuthal_angles=azimuthal_angles,
layer_system=layer_system,
layer_number=layer_number,
layer_system_mediated=True)
pwe_up = pwe_up + pu
pwe_down = pwe_down + pd
return pwe_up, pwe_down
def scattered_field_piecewise_expansion(vacuum_wavelength,
particle_list,
layer_system,
k_parallel='default',
azimuthal_angles='default',
layer_numbers=None):
"""Compute a piecewise field expansion of the scattered field.
Args:
vacuum_wavelength (float): vacuum wavelength
particle_list (list): list of smuthi.particles.Particle objects
layer_system (smuthi.layers.LayerSystem): stratified medium
k_parallel (numpy.ndarray or str): in-plane wavenumbers array.
if 'default', use smuthi.coordinates.default_k_parallel
azimuthal_angles (numpy.ndarray or str): azimuthal angles array
if 'default', use smuthi.coordinates.default_azimuthal_angles
layer_numbers (list): if specified, append only plane wave expansions for these layers
Returns:
scattered field as smuthi.field_expansion.PiecewiseFieldExpansion object
"""
if layer_numbers is None:
layer_numbers = range(layer_system.number_of_layers())
sfld = fldex.PiecewiseFieldExpansion()
for i in tqdm(layer_numbers,
desc='Scatt. field expansion ',
file=sys.stdout,
bar_format='{l_bar}{bar}| elapsed: {elapsed} '
'remaining: {remaining}'):
# layer mediated scattered field ---------------------------------------------------------------------------
k = coord.angular_frequency(
vacuum_wavelength) * layer_system.refractive_indices[i]
ref = [0, 0, layer_system.reference_z(i)]
vb = (layer_system.lower_zlimit(i), layer_system.upper_zlimit(i))
pwe_up = fldex.PlaneWaveExpansion(k=k,
k_parallel=k_parallel,
azimuthal_angles=azimuthal_angles,
kind='upgoing',
reference_point=ref,
lower_z=vb[0],
upper_z=vb[1])
pwe_down = fldex.PlaneWaveExpansion(k=k,
k_parallel=k_parallel,
azimuthal_angles=azimuthal_angles,
kind='downgoing',
reference_point=ref,
lower_z=vb[0],
upper_z=vb[1])
for particle in particle_list:
add_up, add_down = fldex.swe_to_pwe_conversion(
particle.scattered_field, k_parallel, azimuthal_angles,
layer_system, i, True)
pwe_up = pwe_up + add_up
pwe_down = pwe_down + add_down
# in bottom_layer, suppress upgoing waves, and in top layer, suppress downgoing waves
if i > 0:
sfld.expansion_list.append(pwe_up)
if i < layer_system.number_of_layers() - 1:
sfld.expansion_list.append(pwe_down)
# direct field ---------------------------------------------------------------------------------------------
for particle in particle_list:
sfld.expansion_list.append(particle.scattered_field)
return sfld