meanas/meanas/test/test_waveguide_2d_numerics.py

284 lines
8.4 KiB
Python

import numpy
from numpy.linalg import norm
from numpy.testing import assert_allclose
from ..fdmath import vec
from ..fdfd import waveguide_2d
OMEGA = 1 / 1500
GRID_SHAPE = (5, 5)
DXES_2D = [[numpy.ones(GRID_SHAPE[0]), numpy.ones(GRID_SHAPE[1])] for _ in range(2)]
DXES_2D_NONUNIFORM = [[
numpy.array([1.0, 1.2, 0.9, 1.1, 1.3]),
numpy.array([0.8, 1.1, 1.0, 1.2, 0.9]),
] for _ in range(2)]
def build_asymmetric_epsilon() -> numpy.ndarray:
epsilon = numpy.ones((3, *GRID_SHAPE), dtype=float)
epsilon[:, 2, 1] = 2.0
return vec(epsilon)
def build_mu_profile() -> numpy.ndarray:
return numpy.linspace(1.5, 2.2, 3 * GRID_SHAPE[0] * GRID_SHAPE[1])
def test_waveguide_2d_solved_modes_are_ordered_and_low_residual() -> None:
epsilon = build_asymmetric_epsilon()
operator_e = waveguide_2d.operator_e(OMEGA, DXES_2D, epsilon)
e_xys, wavenumbers = waveguide_2d.solve_modes(
[0, 1],
omega=OMEGA,
dxes=DXES_2D,
epsilon=epsilon,
)
assert numpy.all(numpy.diff(numpy.real(wavenumbers)) <= 0)
for e_xy, wavenumber in zip(e_xys, wavenumbers, strict=True):
residual = norm(operator_e @ e_xy - (wavenumber ** 2) * e_xy) / norm(e_xy)
assert residual < 1e-6
def test_waveguide_2d_normalized_fields_are_consistent() -> None:
epsilon = build_asymmetric_epsilon()
operator_h = waveguide_2d.operator_h(OMEGA, DXES_2D, epsilon)
e_xy, wavenumber = waveguide_2d.solve_mode(
0,
omega=OMEGA,
dxes=DXES_2D,
epsilon=epsilon,
)
e_field, h_field = waveguide_2d.normalized_fields_e(
e_xy,
wavenumber=wavenumber,
omega=OMEGA,
dxes=DXES_2D,
epsilon=epsilon,
)
h_xy = numpy.concatenate(numpy.split(h_field, 3)[:2])
overlap = waveguide_2d.inner_product(e_field, h_field, DXES_2D, conj_h=True)
h_residual = norm(operator_h @ h_xy - (wavenumber ** 2) * h_xy) / norm(h_xy)
assert abs(overlap.real - 1.0) < 1e-10
assert abs(overlap.imag) < 1e-10
assert waveguide_2d.e_err(e_field, wavenumber, OMEGA, DXES_2D, epsilon) < 1e-6
assert waveguide_2d.h_err(h_field, wavenumber, OMEGA, DXES_2D, epsilon) < 1e-6
assert h_residual < 1e-6
def test_waveguide_2d_sensitivity_matches_finite_difference() -> None:
epsilon = build_asymmetric_epsilon()
e_xy, wavenumber = waveguide_2d.solve_mode(
0,
omega=OMEGA,
dxes=DXES_2D,
epsilon=epsilon,
)
e_field, h_field = waveguide_2d.normalized_fields_e(
e_xy,
wavenumber=wavenumber,
omega=OMEGA,
dxes=DXES_2D,
epsilon=epsilon,
)
sensitivity = waveguide_2d.sensitivity(
e_field,
h_field,
wavenumber=wavenumber,
omega=OMEGA,
dxes=DXES_2D,
epsilon=epsilon,
)
target_index = int(numpy.argmax(numpy.abs(sensitivity)))
delta = 1e-4
epsilon_perturbed = epsilon.copy()
epsilon_perturbed[target_index] += delta
_, perturbed_wavenumber = waveguide_2d.solve_mode(
0,
omega=OMEGA,
dxes=DXES_2D,
epsilon=epsilon_perturbed,
)
finite_difference = (perturbed_wavenumber - wavenumber) / delta
assert numpy.isfinite(sensitivity[target_index])
assert numpy.isfinite(finite_difference)
assert abs(sensitivity[target_index].imag) < 1e-10
assert abs(finite_difference.imag) < 1e-10
ratio = abs(sensitivity[target_index] / finite_difference)
assert sensitivity[target_index].real > 0
assert finite_difference.real > 0
assert 0.4 < ratio < 1.8
def test_waveguide_2d_normalized_fields_h_are_finite_and_unit_normalized_with_mu() -> None:
epsilon = build_asymmetric_epsilon()
mu = build_mu_profile()
e_xy, wavenumber = waveguide_2d.solve_mode(
0,
omega=OMEGA,
dxes=DXES_2D,
epsilon=epsilon,
)
_e_ref, h_ref = waveguide_2d.normalized_fields_e(
e_xy,
wavenumber=wavenumber,
omega=OMEGA,
dxes=DXES_2D,
epsilon=epsilon,
mu=mu,
)
h_xy = numpy.concatenate(numpy.split(h_ref, 3)[:2])
e_field, h_field = waveguide_2d.normalized_fields_h(
h_xy,
wavenumber=wavenumber,
omega=OMEGA,
dxes=DXES_2D,
epsilon=epsilon,
mu=mu,
)
overlap = waveguide_2d.inner_product(e_field, h_field, DXES_2D, conj_h=True)
assert e_field.shape == (3 * GRID_SHAPE[0] * GRID_SHAPE[1],)
assert h_field.shape == (3 * GRID_SHAPE[0] * GRID_SHAPE[1],)
assert numpy.isfinite(e_field).all()
assert numpy.isfinite(h_field).all()
assert abs(overlap.real - 1.0) < 1e-10
assert abs(overlap.imag) < 1e-10
def test_waveguide_2d_helper_operators_with_mu_return_finite_outputs() -> None:
epsilon = build_asymmetric_epsilon()
mu = build_mu_profile()
e_xy, wavenumber = waveguide_2d.solve_mode(
0,
omega=OMEGA,
dxes=DXES_2D,
epsilon=epsilon,
)
_e_ref, h_ref = waveguide_2d.normalized_fields_e(
e_xy,
wavenumber=wavenumber,
omega=OMEGA,
dxes=DXES_2D,
epsilon=epsilon,
mu=mu,
)
h_xy = numpy.concatenate(numpy.split(h_ref, 3)[:2])
n_pts = GRID_SHAPE[0] * GRID_SHAPE[1]
operators = [
('exy2h', waveguide_2d.exy2h(wavenumber, OMEGA, DXES_2D, epsilon, mu), e_xy),
('hxy2e', waveguide_2d.hxy2e(wavenumber, OMEGA, DXES_2D, epsilon, mu), h_xy),
('hxy2h', waveguide_2d.hxy2h(wavenumber, DXES_2D, mu), h_xy),
]
for _name, operator, vector in operators:
result = operator @ vector
assert operator.shape == (3 * n_pts, 2 * n_pts)
assert numpy.isfinite(operator.data).all()
assert result.shape == (3 * n_pts,)
assert numpy.isfinite(result).all()
def test_waveguide_2d_error_helpers_with_mu_return_finite_values() -> None:
epsilon = build_asymmetric_epsilon()
mu = build_mu_profile()
e_xy, wavenumber = waveguide_2d.solve_mode(
0,
omega=OMEGA,
dxes=DXES_2D,
epsilon=epsilon,
)
e_field, h_field = waveguide_2d.normalized_fields_e(
e_xy,
wavenumber=wavenumber,
omega=OMEGA,
dxes=DXES_2D,
epsilon=epsilon,
mu=mu,
)
h_error = waveguide_2d.h_err(h_field, wavenumber, OMEGA, DXES_2D, epsilon, mu)
e_error = waveguide_2d.e_err(e_field, wavenumber, OMEGA, DXES_2D, epsilon, mu)
assert numpy.isfinite(h_error)
assert numpy.isfinite(e_error)
assert 0 < h_error < 0.1
assert 0 < e_error < 2.0
def test_waveguide_2d_inner_product_phase_and_conjugation_branches() -> None:
epsilon = build_asymmetric_epsilon()
mu = build_mu_profile()
e_xy, wavenumber = waveguide_2d.solve_mode(
0,
omega=OMEGA,
dxes=DXES_2D,
epsilon=epsilon,
)
e_field, h_field = waveguide_2d.normalized_fields_e(
e_xy,
wavenumber=wavenumber,
omega=OMEGA,
dxes=DXES_2D,
epsilon=epsilon,
mu=mu,
)
overlap_no_conj = waveguide_2d.inner_product(e_field, h_field, DXES_2D, conj_h=False)
overlap_conj = waveguide_2d.inner_product(e_field, h_field, DXES_2D, conj_h=True)
overlap_phase = waveguide_2d.inner_product(e_field, h_field, DXES_2D, conj_h=True, prop_phase=0.3)
assert numpy.isfinite(overlap_no_conj)
assert numpy.isfinite(overlap_phase)
assert abs(overlap_no_conj.real - 1.0) < 1e-10
assert abs(overlap_no_conj.imag) < 1e-10
assert_allclose(overlap_phase / overlap_conj, numpy.exp(-0.15j), atol=1e-12, rtol=1e-12)
def test_waveguide_2d_inner_product_trapezoid_branch_on_nonuniform_grid() -> None:
epsilon = build_asymmetric_epsilon()
e_xy, wavenumber = waveguide_2d.solve_mode(
0,
omega=OMEGA,
dxes=DXES_2D_NONUNIFORM,
epsilon=epsilon,
)
e_field, h_field = waveguide_2d.normalized_fields_e(
e_xy,
wavenumber=wavenumber,
omega=OMEGA,
dxes=DXES_2D_NONUNIFORM,
epsilon=epsilon,
)
overlap_rect = waveguide_2d.inner_product(e_field, h_field, DXES_2D_NONUNIFORM, conj_h=True)
overlap_trap = waveguide_2d.inner_product(
e_field,
h_field,
DXES_2D_NONUNIFORM,
conj_h=True,
trapezoid=True,
)
assert numpy.isfinite(overlap_rect)
assert numpy.isfinite(overlap_trap)
assert abs(overlap_rect.imag) < 1e-10
assert abs(overlap_trap.imag) < 1e-10
assert abs(overlap_rect - overlap_trap) > 0.1