from copy import deepcopy
import numpy as np
from axiprop.containers import ScalarFieldEnvelope
from axiprop.lib import (
PropagatorFFT2,
PropagatorFFT2Fresnel,
PropagatorResampling,
PropagatorResamplingFresnel,
)
from axiprop.utils import import_from_lasy_grid
from scipy.constants import c
from .propagator import Propagator
[docs]
class AxipropPropagator(Propagator):
"""
Axiprop's non-paraxial propagator.
This class wraps around Axiprop's PropagatorFFT2 and PropagatorResampling, for 3D cartesian and 2D cylindrical, respectively.
"""
[docs]
def update(self, dim, omega0, containers_in, grid_out=None, verbose=False):
r"""
Initialize or update the propagator if needed.
Parameters
----------
dim : string
Dimensionality of the array. Options are:
- ``'xyt'``: Laser pulse represented on a 3D Cartesian grid.
- ``'rt'`` : Laser pulse represented on a 2D cylindrical grid.
omega0 : float (in rad.s^-1)
The main frequency :math:`\omega_0`, which is defined by the laser
wavelength :math:`\lambda_0`, as :math:`\omega_0 = 2\pi c/\lambda_0`.
containers_in : Axiprop container(s)
An Axiprop container (dim='xyt'), or list of containers (dim='rt', 1 element per mode), with the data of laser to propagate.
grid_out : Grid object (optional)
Grid object on which the propagated laser pulse is defined.
Can be different from laser grid before propagation.
Only supported for rt geometry.
verbose : boolean (optional)
Whether to print intermediate steps.
"""
self.dim = dim
self.omega0 = omega0
self.make_propagator = True
if self.dim == "rt":
self._update_mrt(omega0, containers_in, grid_out, verbose)
else:
assert grid_out is None, "grid_out not supported in xyt, use None"
self._update_xyt(omega0, containers_in, verbose)
def _update_mrt(self, omega0, containers_in, grid_out, verbose):
r"""
Initialize or update the propagator if needed.
Parameters
----------
omega0 : float (in s^-1)
The main frequency :math:`\omega_0`, which is defined by the laser
wavelength :math:`\lambda_0`, as :math:`\omega_0 = 2\pi c/\lambda_0`.
containers_in : Axiprop container(s)
A list of Axiprop containers, with the data of laser to propagate.
grid_out : Grid object (optional)
Grid object on which the propagated laser pulse is defined.
Can be different from laser grid before propagation.
verbose : boolean (optional)
Whether to print intermediate steps.
"""
if hasattr(self, "props_rt"):
grid_changed = False
for im in range(self.m_axis.size):
container_in = containers_in[im]
prop_rt = self.props_rt[im]
try:
assert np.allclose(container_in.r, prop_rt.r)
assert np.allclose(grid_out.axes[0], prop_rt.r_new)
except AssertionError:
grid_changed = True
if not grid_changed:
self.make_propagator = False
if self.make_propagator:
self.props_rt = []
for im in range(self.m_axis.size):
m = self.m_axis[im]
container_in = containers_in[im]
self.props_rt.append(
PropagatorResampling(
r_axis=container_in.r,
kz_axis=container_in.k_freq,
r_axis_new=grid_out.axes[0],
mode=m,
verbose=verbose,
)
)
def _update_xyt(self, omega0, container_in, verbose):
r"""
Initialize or update the propagator if needed.
Parameters
----------
omega0 : float (in s^-1)
The main frequency :math:`\omega_0`, which is defined by the laser
wavelength :math:`\lambda_0`, as :math:`\omega_0 = 2\pi c/\lambda_0`.
containers_in : Axiprop container(s)
An Axiprop container, with the data of laser to propagate.
grid_out : Grid object (optional)
Grid object on which the propagated laser pulse is defined.
Can be different from laser grid before propagation.
Only supported for rt geometry.
verbose : boolean (optional)
Whether to print intermediate steps.
"""
if hasattr(self, "prop_xyt"):
grid_changed = False
try:
assert np.allclose(container_in.x, self.prop_xyt.x)
assert np.allclose(container_in.y, self.prop_xyt.y)
except AssertionError:
grid_changed = True
if not grid_changed:
self.make_propagator = False
if self.make_propagator:
self.prop_xyt = PropagatorFFT2(
x_axis=container_in.x,
y_axis=container_in.y,
kz_axis=container_in.k_freq,
verbose=verbose,
)
[docs]
def propagate(
self,
grid_in,
dim,
omega0,
distance=None,
grid_out=None,
verbose=True,
nr_boundary=0,
):
r"""
Propagate laser pulse in z direction by a given distance.
Currently, the propagation is assumed to take place in vacuum.
This propagator is non-paraxial.
Parameters
----------
grid_in : Grid
Grid object containing the laser to propagate.
dim : string
Dimensionality of the array. Options are:
- ``'xyt'``: Laser pulse represented on a 3D Cartesian grid.
- ``'rt'`` : Laser pulse represented on a 2D cylindrical grid.
omega0 : float (in rad.s^-1)
The main frequency :math:`\omega_0`, which is defined by the laser
wavelength :math:`\lambda_0`, as :math:`\omega_0 = 2\pi c/\lambda_0`.
distance : scalar (optional)
Distance by which the laser is propagated.
grid_out : Grid object (optional)
Grid object on which the propagated laser pulse is defined.
Can be different from laser grid before propagation.
Only supported for 'rt' geometry.
verbose : boolean (optional, default False)
Whether to print intermediate steps.
nr_boundary : int (optional, default 0)
Number of grid points for absorbing boundary condition.
Returns
-------
Grid object with laser data after propagation.
"""
assert distance is not None
if dim == "xyt":
assert grid_out is None, (
"grid_out not yet supported for xyt, please use None"
)
if grid_out is None:
grid_out = deepcopy(grid_in)
if dim == "rt":
field = self._propagate_mrt(
distance, grid_in, omega0, grid_out, verbose, nr_boundary
)
else:
field = self._propagate_xyt(distance, grid_in, omega0, verbose, nr_boundary)
grid_out.position += distance
grid_out.set_temporal_field(field)
return grid_out
def _propagate_mrt(
self, distance, grid_in, omega0, grid_out, verbose=True, nr_boundary=0
):
r"""
Propagate laser pulse in z direction by a given distance.
Currently, the propagation is assumed to take place in vacuum.
This propagator is non-paraxial.
Parameters
----------
distance : scalar
Distance by which the laser is propagated.
grid_in : Grid
Grid object containing the laser to propagate.
omega0 : float (in rad.s^-1)
The main frequency :math:`\omega_0`, which is defined by the laser
wavelength :math:`\lambda_0`, as :math:`\omega_0 = 2\pi c/\lambda_0`.
grid_out : Grid object (optional)
Grid object on which the propagated laser pulse is defined.
Can be different from laser grid before propagation.
verbose : boolean (optional, default False)
Whether to print intermediate steps.
nr_boundary : int (optional, default 0)
Number of grid points for absorbing boundary condition.
Returns
-------
field : ndarray with laser envelope in temporal representation.
"""
containers_in, self.m_axis = import_from_lasy_grid(
grid_in, "rt", omega0, nr_boundary
)
field_3d = np.zeros_like(grid_out.temporal_field)
self.update("rt", omega0, containers_in, grid_out, verbose)
for im in range(self.m_axis.size):
prop_rt = self.props_rt[im]
container_in = containers_in[im]
Field_ft_new = prop_rt.step(
container_in.Field_ft, distance, overwrite=False, show_progress=verbose
)
laser_loc = ScalarFieldEnvelope(
container_in.k0, container_in.t + distance / c, nr_boundary
)
laser_loc.import_field_ft(
Field_ft_new, r_axis=prop_rt.r_new, transform=True, make_copy=False
)
field_3d[im] = laser_loc.Field.T
return field_3d
def _propagate_xyt(self, distance, grid_in, omega0, verbose=True, nr_boundary=0):
r"""
Propagate laser pulse in z direction by a given distance.
Currently, the propagation is assumed to take place in vacuum.
This propagator is non-paraxial.
Parameters
----------
distance : scalar
Distance by which the laser is propagated.
grid_in : Grid
Grid object containing the laser to propagate.
omega0 : float (in rad.s^-1)
The main frequency :math:`\omega_0`, which is defined by the laser
wavelength :math:`\lambda_0`, as :math:`\omega_0 = 2\pi c/\lambda_0`.
verbose : boolean (optional, default False)
Whether to print intermediate steps.
nr_boundary : int (optional, default 0)
Number of grid points for absorbing boundary condition.
Returns
-------
field : ndarray with laser envelope in temporal representation.
"""
container_in = import_from_lasy_grid(grid_in, "xyt", omega0, nr_boundary)
self.update("xyt", omega0, container_in, verbose=verbose)
Field_ft_new = self.prop_xyt.step(
container_in.Field_ft, distance, overwrite=False, show_progress=verbose
)
laser_loc = ScalarFieldEnvelope(
container_in.k0, container_in.t + distance / c, nr_boundary
).import_field_ft(
Field_ft_new,
r_axis=(self.prop_xyt.r, self.prop_xyt.x, self.prop_xyt.y),
transform=True,
make_copy=False,
)
return np.moveaxis(laser_loc.Field, 0, -1)
[docs]
class AxipropFresnelPropagator(Propagator):
"""
Axiprop's paraxial Fresnel propagator.
This class wraps around Axiprop's PropagatorFFT2Fresnel and PropagatorResamplingFresnel, for 3D cartesian and 2D cylindrical, respectively.
"""
[docs]
def update(self, distance, dim, omega0, containers_in, grid_out, verbose=False):
r"""
Initialize or update the propagator if needed.
Parameters
----------
distance : scalar
Distance over which to propagate the laser pulse.
dim : string
Dimensionality of the array. Options are:
- ``'xyt'``: Laser pulse represented on a 3D Cartesian grid.
- ``'rt'`` : Laser pulse represented on a 2D cylindrical grid.
omega0 : float (in rad.s^-1)
The main frequency :math:`\omega_0`, which is defined by the laser
wavelength :math:`\lambda_0`, as :math:`\omega_0 = 2\pi c/\lambda_0`.
containers_in : Axiprop container(s)
An Axiprop container (dim='xyt'), or list of containers (dim='rt', 1 element per mode), with the data of laser to propagate.
grid_out : Grid object
Grid object on which the propagated laser pulse is defined.
Can be different from laser grid before propagation.
verbose : boolean (optional)
Whether to print intermediate steps.
"""
self.dim = dim
self.omega0 = omega0
self.make_propagator = True
if self.dim == "rt":
self._update_mrt(distance, omega0, containers_in, grid_out, verbose)
else:
self._update_xyt(distance, omega0, containers_in, grid_out, verbose)
def _update_mrt(self, distance, omega0, containers_in, grid_out, verbose):
r"""
Initialize or update the propagator if needed.
Parameters
----------
distance : scalar
Distance over which to propagate the laser pulse.
omega0 : float (in rad.s^-1)
The main frequency :math:`\omega_0`, which is defined by the laser
wavelength :math:`\lambda_0`, as :math:`\omega_0 = 2\pi c/\lambda_0`.
containers_in : Axiprop container(s)
A list of Axiprop containers (1 element per mode), with the data of laser to propagate.
grid_out : Grid object
Grid object on which the propagated laser pulse is defined.
Can be different from laser grid before propagation.
verbose : boolean (optional)
Whether to print intermediate steps.
"""
if hasattr(self, "props_rt"):
grid_changed = False
for im in range(self.m_axis.size):
container_in = containers_in[im]
prop_rt = self.props_rt[im]
try:
assert distance == self.distance
assert np.allclose(container_in.r, prop_rt.r)
assert np.allclose(grid_out.axes[0], prop_rt.r_new)
except AssertionError:
grid_changed = True
if not grid_changed:
self.make_propagator = False
if self.make_propagator:
self.props_rt = []
self.distance = distance
for im in range(self.m_axis.size):
m = self.m_axis[im]
container_in = containers_in[im]
self.props_rt.append(
PropagatorResamplingFresnel(
dz=distance,
r_axis=container_in.r,
kz_axis=container_in.k_freq,
r_axis_new=grid_out.axes[0],
mode=m,
verbose=verbose,
)
)
def _update_xyt(self, distance, omega0, container_in, grid_out, verbose):
r"""
Initialize or update the propagator if needed.
Parameters
----------
distance : scalar
Distance over which to propagate the laser pulse.
omega0 : float (in rad.s^-1)
The main frequency :math:`\omega_0`, which is defined by the laser
wavelength :math:`\lambda_0`, as :math:`\omega_0 = 2\pi c/\lambda_0`.
containers_in : Axiprop container(s)
An Axiprop container with the data of laser to propagate.
grid_out : Grid object
Grid object on which the propagated laser pulse is defined.
Can be different from laser grid before propagation.
verbose : boolean (optional)
Whether to print intermediate steps.
"""
if hasattr(self, "prop_xyt"):
grid_changed = False
try:
assert np.allclose(self.distance, distance)
assert np.allclose(container_in.x, self.prop_xyt.x0)
assert np.allclose(container_in.y, self.prop_xyt.y0)
assert np.allclose(grid_out.axes[0], self.prop_xyt.x)
assert np.allclose(grid_out.axes[1], self.prop_xyt.y)
except AssertionError:
grid_changed = True
if not grid_changed:
self.make_propagator = False
if self.make_propagator:
self.distance = distance
self.prop_xyt = PropagatorFFT2Fresnel(
dz=distance,
x_axis=container_in.x,
y_axis=container_in.y,
x_axis_new=grid_out.axes[0],
y_axis_new=grid_out.axes[1],
kz_axis=container_in.k_freq,
verbose=verbose,
)
[docs]
def propagate(
self,
grid_in,
dim,
omega0,
distance=None,
grid_out=None,
verbose=True,
nr_boundary=0,
):
r"""
Propagate laser pulse in z direction by a given distance.
Currently, the propagation is assumed to take place in vacuum.
This is a Fresnel, paraxial propagator.
Parameters
----------
distance : scalar
Distance by which the laser is propagated.
grid_in : Grid
Grid object containing the laser to propagate.
dim : string
Dimensionality of the array. Options are:
- ``'xyt'``: Laser pulse represented on a 3D Cartesian grid.
- ``'rt'`` : Laser pulse represented on a 2D cylindrical grid.
omega0 : float (in rad.s^-1)
The main frequency :math:`\omega_0`, which is defined by the laser
wavelength :math:`\lambda_0`, as :math:`\omega_0 = 2\pi c/\lambda_0`.
grid_out : Grid object (optional)
Grid object on which the propagated laser pulse is defined.
Can be different from laser grid before propagation.
verbose : boolean (optional, default False)
Whether to print intermediate steps.
nr_boundary : int (optional, default 0)
Number of grid points for absorbing boundary condition.
Returns
-------
Grid object with laser data after propagation.
"""
if grid_out is None:
print("`grid_out` is required for this propagator")
return grid_in
if dim == "rt":
field = self._propagate_mrt(
distance, grid_in, omega0, grid_out, verbose, nr_boundary
)
else:
field = self._propagate_xyt(
distance, grid_in, omega0, grid_out, verbose, nr_boundary
)
grid_out.set_temporal_field(field)
grid_out.position += distance
return grid_out
def _propagate_mrt(
self, distance, grid_in, omega0, grid_out, verbose=True, nr_boundary=0
):
r"""
Propagate laser pulse in z direction by a given distance.
Currently, the propagation is assumed to take place in vacuum.
This propagator is a Fresnel, paraxial propagator.
Parameters
----------
distance : scalar
Distance by which the laser is propagated.
grid_in : Grid
Grid object containing the laser to propagate.
omega0 : float (in rad.s^-1)
The main frequency :math:`\omega_0`, which is defined by the laser
wavelength :math:`\lambda_0`, as :math:`\omega_0 = 2\pi c/\lambda_0`.
grid_out : Grid object
Grid object on which the propagated laser pulse is defined.
Can be different from laser grid before propagation.
verbose : boolean (optional, default False)
Whether to print intermediate steps.
nr_boundary : int (optional, default 0)
Number of grid points for absorbing boundary condition.
Returns
-------
field : ndarray with laser envelope in temporal representation.
"""
containers_in, self.m_axis = import_from_lasy_grid(
grid_in, "rt", omega0, nr_boundary
)
field_3d = np.zeros_like(grid_out.temporal_field)
self.update(distance, "rt", omega0, containers_in, grid_out, verbose)
for im in range(self.m_axis.size):
prop_rt = self.props_rt[im]
container_in = containers_in[im]
Field_ft_new = prop_rt.step(
container_in.Field_ft, distance, overwrite=False, show_progress=verbose
)
laser_loc = ScalarFieldEnvelope(
container_in.k0, container_in.t + distance / c, nr_boundary
)
laser_loc.import_field_ft(
Field_ft_new, r_axis=prop_rt.r_new, transform=True, make_copy=False
)
field_3d[im] = laser_loc.Field.T
return field_3d
def _propagate_xyt(
self, distance, grid_in, omega0, grid_out, verbose=True, nr_boundary=0
):
r"""
Propagate laser pulse in z direction by a given distance.
Currently, the propagation is assumed to take place in vacuum.
This propagator is a Fresnel, paraxial propagator.
Parameters
----------
distance : scalar
Distance by which the laser is propagated.
grid_in : Grid
Grid object containing the laser to propagate.
omega0 : float (in rad.s^-1)
The main frequency :math:`\omega_0`, which is defined by the laser
wavelength :math:`\lambda_0`, as :math:`\omega_0 = 2\pi c/\lambda_0`.
grid_out : Grid object
Grid object on which the propagated laser pulse is defined.
Can be different from laser grid before propagation.
verbose : boolean (optional, default False)
Whether to print intermediate steps.
nr_boundary : int (optional, default 0)
Number of grid points for absorbing boundary condition.
Returns
-------
field : ndarray with laser envelope in temporal representation.
"""
container_in = import_from_lasy_grid(grid_in, "xyt", omega0, nr_boundary)
self.update(distance, "xyt", omega0, container_in, grid_out, verbose)
Field_ft_new = self.prop_xyt.step(
container_in.Field_ft, distance, overwrite=False, show_progress=verbose
)
laser_loc = ScalarFieldEnvelope(
container_in.k0, container_in.t + distance / c, nr_boundary
).import_field_ft(
Field_ft_new,
r_axis=(self.prop_xyt.r, self.prop_xyt.x, self.prop_xyt.y),
transform=True,
make_copy=False,
)
return np.moveaxis(laser_loc.Field, 0, -1)
