def test_rotated_spheroid_equals_rotated_light(material, atol):
"""cross-sections are the same if a spheroid is rotated or if the light is rotated"""
theta = 1.3
phi = 0.7
source = miepy.sources.plane_wave([1,0], theta=theta, phi=phi)
z_oriented = miepy.cluster(particles=miepy.spheroid([0,0,0], radius, 2*radius, material),
source=source,
wavelength=wavelength,
lmax=lmax,
medium=medium)
C1 = z_oriented.cross_sections()
source = miepy.sources.plane_wave([1,0])
q = miepy.quaternion.from_spherical_coords(theta, phi).inverse()
oriented = miepy.cluster(particles=miepy.spheroid([0,0,0], radius, 2*radius, material, orientation=q),
source=source,
wavelength=wavelength,
lmax=lmax,
medium=medium)
C2 = oriented.cross_sections()
assert np.allclose(C1, C2, rtol=0, atol=atol)
def test_sphere_cluster_tmatrix_particle():
"""sphere_cluster_particle in miepy.cluster yields the same results as miepy.sphere_cluster"""
L = 155*nm
lmax = 6
cluster = miepy.sphere_cluster(position=[[-L/2, 0,0], [L/2,0,0]],
material=Ag,
radius=75*nm,
source=source,
lmax=lmax,
medium=medium,
wavelength=800*nm)
C1 = cluster.cross_sections()
cluster.solve_cluster_coefficients()
p1 = cluster.p_cluster
particle = miepy.sphere_cluster_particle(cluster.position, cluster.radius, Ag, lmax=lmax)
cluster = miepy.cluster(particles=particle,
source=source,
lmax=lmax,
medium=medium,
wavelength=800*nm)
C2 = cluster.cross_sections()
p2 = cluster.p_scat
assert np.allclose(C1, C2, rtol=7e-4, atol=0), 'equal cross-sections'
assert np.allclose(p1, p2, rtol=1e-2, atol=1e-12), 'equal cluster scattering coefficients'
def force_gmmt():
wavelengths = np.linspace(400 * nm, 1000 * nm, 100)
eps = meep_ext.get_eps(material)(wavelengths)
Au = miepy.data_material(wavelengths, eps)
# Au = miepy.constant_material(3.5**2)
# Au = miepy.materials.Au()
particles = []
for i in range(9):
orientation = miepy.quaternion.from_spherical_coords(theta[i], phi[i])
particles.append(
miepy.cylinder(position=[x[i], y[i], z[i]],
radius=radius,
height=height,
material=Au,
orientation=orientation))
F = np.zeros([3, 9, len(wavelengths)], dtype=float)
for i, wavelength in enumerate(pbar(wavelengths)):
sol = miepy.cluster(particles=particles,
source=miepy.sources.plane_wave([1, 0]),
wavelength=wavelength,
lmax=4)
F[..., i] = sol.force()
# if i == 0:
# miepy.visualize(sol)
return dict(wavelengths=wavelengths, force=F)
def gmt_sim():
material = miepy.materials.constant_material(3**2)
q = miepy.quaternion.from_spherical_coords(0, 0)
particles = [
miepy.regular_prism([0, 0, 0],
4,
width=W,
height=H,
material=material,
orientation=q)
]
c = miepy.cluster(particles=particles,
source=miepy.sources.plane_wave([1, 1j]),
wavelength=600 * nm,
lmax=8)
x = np.linspace(-1.5 * W, 1.5 * W, 150)
y = np.linspace(-1.5 * W, 1.5 * W, 150)
X, Y = np.meshgrid(x, y)
Z = np.zeros_like(X)
E = c.E_field(X, Y, Z, mask=True)
Ixy = np.sum(np.abs(E)**2, axis=0)
R = particles[0].enclosed_radius() + 20 * nm
phi = np.linspace(0, 2 * np.pi, 50)
x = R * np.cos(phi)
y = R * np.sin(phi)
z = np.zeros_like(x)
E = c.E_field(x, y, z)
Iphi = np.sum(np.abs(E)**2, axis=0)
return dict(phi=phi, X=X, Y=Y, Ixy=Ixy, Iphi=Iphi)
def force_gmmt():
wavelengths = np.linspace(400 * nm, 1000 * nm, 100)
# eps = meep_ext.get_eps(material)(wavelengths)
# Au = miepy.data_material(wavelengths, eps)
material = miepy.constant_material(3.5**2)
particles = [
miepy.cube([-sep / 2, 0, 0], 200 * nm, material),
miepy.cube([sep / 2, 0, 0], 200 * nm, material)
]
F1 = np.zeros((3, ) + wavelengths.shape, dtype=float)
F2 = np.zeros((3, ) + wavelengths.shape, dtype=float)
for i, wavelength in enumerate(pbar(wavelengths)):
c = miepy.cluster(particles=particles,
source=miepy.sources.plane_wave([1, 0]),
wavelength=wavelength,
lmax=4)
q = miepy.quaternion.from_spherical_coords(0, 0)
c.update(orientation=[q, q])
F1[:, i] = c.force_on_particle(1)
q = miepy.quaternion.from_spherical_coords(0, np.pi / 4)
c.update(orientation=[q, q])
F2[:, i] = c.force_on_particle(1)
return dict(wavelengths=wavelengths, F1=F1, F2=F2)
def vis():
fig, ax = plt.subplots()
norm = job.load(norm_sim)
scat = job.load(scat_sim)
ax.plot((1 / nm) / norm.frequency,
scat.scattering / norm.incident * norm.area,
'o',
color='C0',
label='scattering (FDTD)')
ax.plot((1 / nm) / norm.frequency,
scat.absorption / norm.incident * norm.area,
'o',
color='C1',
label='absorption (FDTD)')
ax.plot((1 / nm) / norm.frequency,
(scat.scattering + scat.absorption) / norm.incident * norm.area,
'o',
color='C2',
label='extinction (FDTD)')
wavelengths = np.linspace(400 * nm, 1000 * nm, 100)
eps = meep_ext.get_eps(material)(wavelengths)
Au = miepy.data_material(wavelengths, eps)
# Au = miepy.constant_material(3.5**2)
C, A, E = [np.zeros_like(wavelengths) for i in range(3)]
particles = []
for i in range(9):
orientation = miepy.quaternion.from_spherical_coords(theta[i], phi[i])
particles.append(
miepy.cylinder(position=[x[i], y[i], z[i]],
radius=radius,
height=height,
material=Au,
orientation=orientation))
for i, wavelength in enumerate(pbar(wavelengths)):
sol = miepy.cluster(particles=particles,
source=miepy.sources.plane_wave([1, 0]),
wavelength=wavelength,
lmax=3)
C[i], A[i], E[i] = sol.cross_sections()
ax.axhline(0, linestyle='--', color='black')
ax.plot(wavelengths / nm, C, color='C0', label='scattering (GMT)')
ax.plot(wavelengths / nm, A, color='C1', label='absorption (GMT)')
ax.plot(wavelengths / nm, E, color='C2', label='extinction (GMT)')
ax.legend()
ax.set(xlabel='wavelength (nm)', ylabel='cross-section')
plt.show()
def gmt_sim():
wavelengths = np.linspace(400 * nm, 1000 * nm, 100)
eps = meep_ext.get_eps(material)(wavelengths)
Au = miepy.data_material(wavelengths, eps)
Au = miepy.constant_material(3.5**2)
C, A, E = [np.zeros_like(wavelengths) for i in range(3)]
particles = []
# orientation = miepy.quaternion.from_spherical_coords(theta[i], phi[i])
particles.append(miepy.cube([0, 0, 0], W, material=Au, orientation=q))
for i, wavelength in enumerate(tqdm(wavelengths)):
sol = miepy.cluster(particles=particles,
source=miepy.sources.plane_wave([1, 0]),
wavelength=wavelength,
lmax=4)
C[i], A[i], E[i] = sol.cross_sections()
return dict(wavelengths=wavelengths, C=C, A=A, E=E)
def tests(Nmax, step=1):
Nparticles = np.arange(1, Nmax+1, step)
t_force, t_flux, t_build, t_solve, t_expand, t_tmatrix = [np.zeros_like(Nparticles, dtype=float) for i in range(6)]
for i,N in enumerate(Nparticles):
print(N, Nmax)
positions = [[n*separation, 0, 0] for n in range(N)]
particles = [miepy.spheroid(pos, radius, 0.5*radius, Ag) for pos in positions]
mie = miepy.cluster(particles=particles,
source=source,
wavelength=600*nm,
lmax=2)
t_force[i] = time_function(mie.force)
t_flux[i] = time_function(mie.cross_sections)
t_build[i] = time_function(partial(miepy.interactions.particle_aggregate_tmatrix,
mie.position, mie.tmatrix, mie.material_data.k_b))
A = miepy.interactions.particle_aggregate_tmatrix(mie.position, mie.tmatrix, k=mie.material_data.k_b)
t_solve[i] = time_function(partial(solve_linear_system, A, mie.p_src, method=miepy.solver.bicgstab))
t_tmatrix[i] = time_function(partial(tmatrix_time, mie))
x = np.linspace(0, N*separation, 1)
y = 2*radius*np.ones_like(x)
z = np.zeros_like(x)
t_expand[i] = time_function(partial(mie.E_field, x, y, z))
fig, ax = plt.subplots()
ax.plot(Nparticles, t_force, label='force')
ax.plot(Nparticles, t_flux, label='flux')
ax.plot(Nparticles, t_build, label='build')
ax.plot(Nparticles, t_solve, label='solve')
ax.plot(Nparticles, t_expand, label='expand')
ax.plot(Nparticles, t_tmatrix, label='tmatrix')
ax.legend()
ax.set(xlabel='number of particles', ylabel='runtime (s)')
plt.show()
def test_tmatrix_sphere_is_sphere(material, atol):
"""tmatrix method with spheres should be equivalent to sphere cluster"""
position = [[-300*nm, 0, 0], [300*nm, 0, 0]]
spheres = miepy.sphere_cluster(position=position,
radius=radius,
material=material,
source=source,
wavelength=wavelength,
lmax=lmax,
medium=medium)
particles = [miepy.sphere(pos, radius, material) for pos in position]
cluster = miepy.cluster(particles=particles,
source=source,
wavelength=wavelength,
lmax=lmax,
medium=medium)
print(np.max(np.abs(spheres.p_inc - cluster.p_inc)))
assert np.allclose(spheres.p_inc, cluster.p_inc, rtol=0, atol=atol)