def check_rotation(self, mat, L, fsrc, zsrc, resolution, tmax, zout, kpred, tol=1.5):
cell = mp.Vector3(0, 0, L)
pml_layers = [mp.PML(thickness=1.0, direction=mp.Z)]
sources = [mp.Source(mp.ContinuousSource(frequency=fsrc),
component=mp.Ex, center=mp.Vector3(0, 0, zsrc))]
self.sim = mp.Simulation(cell_size=cell, geometry=[], sources=sources,
boundary_layers=pml_layers,
default_material=mat, resolution=resolution)
record_vol = mp.Volume(center=mp.Vector3(0, 0, zout))
record_Ex, record_Ey, record_t = [], [], []
def record_ex_ey(sim):
record_Ex.append(sim.get_array(vol=record_vol, component=mp.Ex))
record_Ey.append(sim.get_array(vol=record_vol, component=mp.Ey))
record_t.append(sim.meep_time())
self.sim.run(mp.after_time(0.5*tmax, mp.at_every(1e-6, record_ex_ey)), until=tmax)
ex_rel = np.amax(abs(np.fft.fft(record_Ex)))
ey_rel = np.amax(abs(np.fft.fft(record_Ey)))
result = np.arctan2(ey_rel, ex_rel) * 180/np.pi
Ex_theory = np.abs(np.cos(kpred * (zout - zsrc)).real)
Ey_theory = np.abs(np.sin(kpred * (zout - zsrc)).real)
expected = np.arctan2(Ey_theory, Ex_theory) * 180/np.pi
print("Rotation angle (in degrees): {}, expected {}\n".format(result, expected))
np.testing.assert_allclose(expected, result, atol=tol)
ml_atom = mp.MultilevelAtom(sigma=1, transitions=transitions, initial_populations=[N0])
two_level = mp.Medium(index=ncav, E_susceptibilities=[ml_atom])
# Specify the cavity geometry:
geometry = [mp.Block(center=mp.Vector3(z=-0.5*sz+0.5*Lcav),
size=mp.Vector3(mp.inf,mp.inf,Lcav), material=two_level)]
sim = mp.Simulation(cell_size=cell_size,
resolution=resolution,
boundary_layers=pml_layers,
geometry=geometry,
dimensions=dimensions)
sim.init_sim()
def field_func(p):
return 1 if p.z==-0.5*sz + 0.5*Lcav else 0
sim.fields.initialize_field(mp.Ex, field_func)
# Specify the end time:
endt = 7000
# Note that the total number of time steps run is endt*resolution*2. This is the origin of the extra
# factor of 2 in the definition of dt in fieldfft_meep.m.
def print_field(sim):
fp = sim.get_field_point(mp.Ex, mp.Vector3(z=(-0.5 * sz) + Lcav + (0.5 * dpad))).real
print("field:, {}, {}".format(sim.meep_time(), fp))
sim.run(mp.after_time(endt - 250, print_field), until=endt)
sim = mp.Simulation(cell_size=cell_size,
resolution=resolution,
boundary_layers=pml_layers,
geometry=geometry,
dimensions=dimensions)
sim.init_sim()
def field_func(p):
return 1 if p.z == -0.5 * sz + 0.5 * Lcav else 0
sim.fields.initialize_field(mp.Ex, field_func)
# Specify the end time:
endt = 7000
# Note that the total number of time steps run is endt*resolution*2. This is the origin of the extra
# factor of 2 in the definition of dt in fieldfft_meep.m.
def print_field(sim):
fp = sim.get_field_point(mp.Ex,
mp.Vector3(z=(-0.5 * sz) + Lcav +
(0.5 * dpad))).real
print("field:, {}, {}".format(sim.meep_time(), fp))
sim.run(mp.after_time(endt - 250, print_field), until=endt)