"""Optical components performing directional suppression of beams."""
import logging
import finesse
import numpy as np
from finesse.components.node import NodeType, NodeDirection
from finesse.components.general import (
Connector,
InteractionType,
)
from finesse.parameter import float_parameter
from finesse.utilities import refractive_index
from finesse.symbols import Matrix
LOGGER = logging.getLogger(__name__)
[docs]@float_parameter("S", "Power suppression")
# IMPORTANT: renaming this class impacts the katscript spec and should be avoided!
class Isolator(Connector):
"""Represents an isolator optical component with a suppression factor.
Parameters
----------
name : str
Name of newly created isolator.
S : float
Power suppression in dB.
"""
[docs] def __init__(self, name, S=0.0):
super().__init__(name)
self.S = S
self._add_port("p1", NodeType.OPTICAL)
self.p1._add_node("i", NodeDirection.INPUT)
self.p1._add_node("o", NodeDirection.OUTPUT)
self._add_port("p2", NodeType.OPTICAL)
self.p2._add_node("i", NodeDirection.INPUT)
self.p2._add_node("o", NodeDirection.OUTPUT)
# optic to optic couplings
self._register_node_coupling(
"P1i_P2o",
self.p1.i,
self.p2.o,
interaction_type=InteractionType.TRANSMISSION,
)
self._register_node_coupling(
"P2i_P1o",
self.p2.i,
self.p1.o,
interaction_type=InteractionType.TRANSMISSION,
)
[docs] def optical_equations(self):
with finesse.symbols.simplification():
S = 10 ** (-self.S.ref / 20)
if self._model._settings.is_modal:
return {
f"{self.name}.P1i_P2o": S * Matrix(f"{self.name}.K12"),
f"{self.name}.P2i_P1o": S * Matrix(f"{self.name}.K21"),
}
else:
return {
f"{self.name}.P1i_P2o": S,
f"{self.name}.P2i_P1o": S,
}
def _get_workspace(self, sim):
from finesse.components.modal.isolator import IsolatorWorkspace
_, is_changing = self._eval_parameters()
refill = sim.is_component_in_mismatch_couplings(self) or len(is_changing)
ws = IsolatorWorkspace(self, sim)
# This assumes that nr1/nr2 cannot change during a simulation
ws.nr1 = refractive_index(self.p1)
ws.nr2 = refractive_index(self.p2)
ws.add_fill_function(self._fill_matrix, refill)
if sim.is_modal:
ws.set_knm_info(
"P1i_P2o", nr_from=ws.nr1, nr_to=ws.nr2, is_transmission=True
)
ws.set_knm_info(
"P2i_P1o", nr_from=ws.nr2, nr_to=ws.nr1, is_transmission=True
)
return ws
def _fill_matrix(self, ws):
values, _ = self._eval_parameters()
suppression = 10 ** (-values["S"] / 20)
for freq in ws.sim.frequencies:
with ws.sim.component_edge_fill3(
ws.owner_id, ws.connections.P1i_P2o_idx, freq.index, freq.index
) as mat:
mat[:] = ws.K12.data
with ws.sim.component_edge_fill3(
ws.owner_id,
ws.connections.P2i_P1o_idx,
freq.index,
freq.index,
) as mat:
np.multiply(suppression, ws.K21.data, out=mat[:])