"""User-defined Gaussian beam tracing dependencies at a node."""
from itertools import chain
from finesse.exceptions import FinesseException
from ..config import config_instance
from ..parameter import float_parameter
from ..gaussian import BeamParam
from .node import OpticalNode
from .trace_dependency import TraceDependency
[docs]@float_parameter("w0x", "Waist size (x)", units="m", validate="_validate_w0x")
@float_parameter("w0y", "Waist size (y)", units="m", validate="_validate_w0y")
@float_parameter("zx", "Distance to waist (x)", units="m", validate="_validate_zx")
@float_parameter("zy", "Distance to waist (y)", units="m", validate="_validate_zy")
class Gauss(TraceDependency):
"""Beam parameter at a specific node of a model.
The following are legal initialisations of a `Gauss`
object::
# Non-astigmatic
q = Gauss('name', node, q=q)
q = Gauss('name', node, w0=w0, z=z) # waist size and position
q = Gauss('name', node, zr=zr, z=z) # Rayleigh range and waist position
q = Gauss('name', node, w=w, Rc=Rc) # beam size and RoC
q = Gauss('name', node, w=w, S=S) # beam size and curvature
# Astigmatic
q = Gauss('name', node, qx=qx, qy=qy)
q = Gauss('name', node, w0x=wx, zx=zx, w0y=wy, zy=zy)
q = Gauss('name', node, zrx=zrx, zx=zx, zry=zry, zy=zy)
q = Gauss('name', node, wx=wx, Rcx=Rcx, wy=wy, Rcy=Rcy)
q = Gauss('name', node, wx=wx, Sx=Sx, wy=wy, Sy=Sy)
See :class:`.gaussian.BeamParam` for more detailed descriptions
of these variables.
"""
def __init__(self, name, node, priority=0, **kwargs):
super().__init__(name, priority)
if isinstance(node, OpticalNode):
self.__node = node
else:
raise FinesseException(
f"Gauss {self.name} expected argument `node` to be an OpticalNode"
)
wl, nr = self.__get_lambda0_nr()
# Handle q differently so that inner type of a BeamTraceSolution
# can be used directly via this argument
if "q" in kwargs:
if len(kwargs) > 1:
raise ValueError("Cannot specify both q and another parameter")
from ..solutions.beamtrace import BeamTraceSolution
if isinstance(kwargs["q"], BeamTraceSolution.NodeData):
qx, qy = kwargs["q"]
else:
qx = qy = BeamParam(wavelength=wl, nr=nr, q=kwargs["q"])
else:
astig_params = [
("qx", "qy"),
("zrx", "zry", "zx", "zy"),
("w0x", "w0y", "zx", "zy"),
("Rcx", "Rcy", "wx", "wy"),
("Sx", "Sy", "wx", "wy"),
]
# Non-astigmatic beam parameters
if not len(set(chain.from_iterable(astig_params)) & kwargs.keys()):
try:
qx = qy = BeamParam(wavelength=wl, nr=nr, **kwargs)
except ValueError as ex:
raise ValueError(
"Invalid arguments for non-astigmatic Gauss." + str(ex)
)
# Astigmatic beam parameters
else:
astig_params = [tuple(sorted(comb)) for comb in astig_params]
if tuple(sorted(kwargs)) not in astig_params:
raise ValueError(
"Invalid arguments for astigmatic Gauss. Expected one of:\n - "
+ "\n - ".join([", ".join(comb) for comb in astig_params])
)
# Separate the tangential and sagittal plane arguments
xargs = {k.split("x")[0]: v for k, v in kwargs.items() if "x" in k}
yargs = {k.split("y")[0]: v for k, v in kwargs.items() if "y" in k}
qx = BeamParam(wavelength=wl, nr=nr, **xargs)
qy = BeamParam(wavelength=wl, nr=nr, **yargs)
self.__qx = qx
self.__qy = qy
self._specified_params = kwargs
self.w0x = self.__qx.w0
self.zx = self.__qx.z
self.w0y = self.__qy.w0
self.zy = self.__qy.z
# def _on_add(self, model):
# if model is not self.node._model:
# raise Exception(
# f"{repr(self)} is using a node {self.node} from a different model"
# )
def __get_lambda0_nr(self):
if self.__node.component.has_model:
wl = self.__node._model.lambda0
space = self.__node.space
if space is not None:
nr = space.nr.value
else:
nr = 1.0
else:
wl = config_instance()["constants"].getfloat("lambda0")
nr = 1.0
return wl, nr
@property
def qx(self):
"""Tangential plane beam parameter.
:getter: Returns the beam parameter in the tangential plane.
:setter: Sets the beam parameter for the tangential plane.
"""
return self.__qx
@qx.setter
def qx(self, value):
if not isinstance(value, BeamParam):
qx = BeamParam(*self.__get_lambda0_nr(), q=value)
else:
qx = value
self.__qx = qx
self.w0x = self.__qx.w0
self.zx = self.__qx.z
@property
def qy(self):
"""Sagittal plane beam parameter.
:getter: Returns the beam parameter in the sagittal plane.
:setter: Sets the beam parameter for the sagittal plane.
"""
return self.__qy
@qy.setter
def qy(self, value):
if not isinstance(value, BeamParam):
qy = BeamParam(*self.__get_lambda0_nr(), q=value)
else:
qy = value
self.__qy = qy
self.w0y = self.__qy.w0
self.zy = self.__qy.z
@property
def node(self):
"""The optical node associated with the `Gauss` object.
:getter: Returns the associated :class:`.OpticalNode` instance (read-only).
"""
return self.__node
@property
def is_changing(self):
"""Whether the Gauss object is changing or not.
This is used internally when initialising simulation states.
"""
params = (self.w0x, self.w0y, self.zx, self.zy)
return any(p.is_changing for p in params)
def _validate_w0x(self, value):
if not value > 0:
raise ValueError("Waist size must be a positive number.")
self.__qx.w0 = value
return value
def _validate_w0y(self, value):
if not value > 0:
raise ValueError("Waist size must be a positive number.")
self.__qy.w0 = value
return value
def _validate_zx(self, value):
self.__qx.z = value
return value
def _validate_zy(self, value):
self.__qy.z = value
return value