def force_sim():
"""perform scattering simulation"""
sim = meep.Simulation(cell_size=cell,
boundary_layers=[pml],
geometry=geometry,
default_material=medium,
resolution=resolution)
sim.init_fields()
source(sim)
L = 2*radius + 2*particle_monitor_gap
forces = {}
for i in range(9):
p = meep.Vector3(x[i], y[i], z[i])
key = 'N{i}_F{c}'
forces[key.format(i=i, c='x')] = meep_ext.add_force_box(sim, fcen, df, nfreq, p, [L,L,L], meep.X)
forces[key.format(i=i, c='y')] = meep_ext.add_force_box(sim, fcen, df, nfreq, p, [L,L,L], meep.Y)
forces[key.format(i=i, c='z')] = meep_ext.add_force_box(sim, fcen, df, nfreq, p, [L,L,L], meep.Z)
sim.run(until_after_sources=meep.stop_when_fields_decayed(.5*um, decay,
pt=meep.Vector3(0,0,monitor_size[2]/2), decay_by=1e-8))
ret = {}
for i in range(9):
for c in ['x', 'y', 'z']:
key = f'N{i}_F{c}'
ret[key] = np.array(meep.get_forces(forces[key]))
ret['frequency'] = np.array(meep.get_force_freqs(forces['N1_Fx']))
return ret
def force_sim():
"""perform scattering simulation"""
sim = meep.Simulation(cell_size=cell,
boundary_layers=[pml],
geometry=geometry,
default_material=medium,
resolution=resolution)
sim.init_fields()
source(sim)
L = 2**.5 * W + 2 * particle_monitor_gap
p = meep.Vector3(sep / 2, 0, 0)
Fx_mon = meep_ext.add_force_box(sim, fcen, df, nfreq, p, [L, L, L], meep.X)
Fy_mon = meep_ext.add_force_box(sim, fcen, df, nfreq, p, [L, L, L], meep.Y)
Fz_mon = meep_ext.add_force_box(sim, fcen, df, nfreq, p, [L, L, L], meep.Z)
sim.run(until_after_sources=meep.stop_when_fields_decayed(
.5 * um,
decay,
pt=meep.Vector3(0, 0, monitor_size[2] / 2),
decay_by=1e-5))
Fx = np.array(meep.get_forces(Fx_mon))
Fy = np.array(meep.get_forces(Fy_mon))
Fz = np.array(meep.get_forces(Fz_mon))
frequency = np.array(meep.get_force_freqs(Fx_mon))
return dict(frequency=frequency, Fx=Fx, Fy=Fy, Fz=Fz)
def dimer_scat():
"""perform scattering simulation"""
scat = meep.Simulation(cell_size=cell,
boundary_layers=[pml],
geometry=geometry,
resolution=resolution)
scat.init_fields()
source(scat)
L = 2 * radius + 2 * particle_monitor_gap
Fx = meep_ext.add_force_box(scat, fcen, df, nfreq, p2, [L, L, L], meep.X)
Fy = meep_ext.add_force_box(scat, fcen, df, nfreq, p2, [L, L, L], meep.Y)
Fz = meep_ext.add_force_box(scat, fcen, df, nfreq, p2, [L, L, L], meep.Z)
# scat.run(until_after_sources=8*um)
scat.run(until_after_sources=meep.stop_when_fields_decayed(
.5 * um, meep.Ex, pt=p2 - meep.Vector3(0, 0, L / 2), decay_by=1e-7))
return {
'Fx': np.array(meep.get_forces(Fx)),
'Fy': np.array(meep.get_forces(Fy)),
'Fz': np.array(meep.get_forces(Fz)),
'frequency': np.array(meep.get_force_freqs(Fx))
}
def sim(separation):
"""perform scattering simulation"""
L = separation + 2*radius + 2*pml_monitor_gap + 2*particle_monitor_gap + 2*pml.thickness
cell = meep.Vector3(L,L,L)
p1 = meep.Vector3(-separation/2, 0, 0)
p2 = meep.Vector3(separation/2, 0, 0)
geometry = [meep.Sphere(center=p1,
radius=radius,
material=gold),
meep.Sphere(center=p2,
radius=radius,
material=gold)]
scat = meep.Simulation(cell_size=cell,
boundary_layers=[pml],
geometry=geometry,
resolution=resolution)
scat.init_fields()
source(scat)
L = 2*radius + 2*particle_monitor_gap
Fx = meep_ext.add_force_box(scat, fcen, 0, 1, p2, [L,L,L], meep.X)
Fy = meep_ext.add_force_box(scat, fcen, 0, 1, p2, [L,L,L], meep.Y)
Fz = meep_ext.add_force_box(scat, fcen, 0, 1, p2, [L,L,L], meep.Z)
# scat.run(until_after_sources=8*um)
scat.run(until_after_sources=meep.stop_when_fields_decayed(.5*um, meep.Ex,
pt=p2-meep.Vector3(0,0,L/2), decay_by=1e-5))
return {'Fx': np.array(meep.get_forces(Fx))[0], 'Fy': np.array(meep.get_forces(Fy))[0], 'Fz': np.array(meep.get_forces(Fz))[0]}