"""Optical components performing directional redirection of beams."""
import logging
import numpy as np
from finesse.components.general import Connector, InteractionType
from finesse.components.node import NodeDirection, NodeType
from finesse.utilities import refractive_index
LOGGER = logging.getLogger(__name__)
# IMPORTANT: renaming this class impacts the katscript spec and should be avoided!
[docs]class DirectionalBeamsplitter(Connector):
"""Represents a directional beamsplitter optical component. Connections made between
ports:
* port 1 to port 3
* port 3 to port 4
* port 4 to port 2
* port 2 to port 1
Parameters
----------
name : str
Name of newly created directional beamsplitter.
"""
def __init__(self, name):
super().__init__(name)
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)
self._add_port("p3", NodeType.OPTICAL)
self.p3._add_node("i", NodeDirection.INPUT)
self.p3._add_node("o", NodeDirection.OUTPUT)
self._add_port("p4", NodeType.OPTICAL)
self.p4._add_node("i", NodeDirection.INPUT)
self.p4._add_node("o", NodeDirection.OUTPUT)
# optic to optic couplings
self._register_node_coupling(
"P1i_P3o",
self.p1.i,
self.p3.o,
interaction_type=InteractionType.TRANSMISSION,
)
self._register_node_coupling(
"P3i_P4o",
self.p3.i,
self.p4.o,
interaction_type=InteractionType.TRANSMISSION,
)
self._register_node_coupling(
"P4i_P2o",
self.p4.i,
self.p2.o,
interaction_type=InteractionType.TRANSMISSION,
)
self._register_node_coupling(
"P2i_P1o",
self.p2.i,
self.p1.o,
interaction_type=InteractionType.TRANSMISSION,
)
def _get_workspace(self, sim):
from finesse.components.modal.workspace import KnmConnectorWorkspace
class DBSWorkspace(KnmConnectorWorkspace):
def __init__(self, owner, sim):
super().__init__(owner, sim)
ws = DBSWorkspace(self, sim)
ws.I = np.eye(sim.model_settings.num_HOMs, dtype=np.complex128)
ws.carrier.add_fill_function(self._fill_carrier, False)
if sim.signal:
ws.signal.add_fill_function(self._fill_signal, False)
ws.nr1 = refractive_index(self.p1)
ws.nr2 = refractive_index(self.p2)
ws.nr3 = refractive_index(self.p3)
ws.nr4 = refractive_index(self.p4)
if sim.is_modal:
ws.set_knm_info(
"P1i_P3o", nr_from=ws.nr1, nr_to=ws.nr3, is_transmission=True
)
ws.set_knm_info(
"P3i_P4o", nr_from=ws.nr3, nr_to=ws.nr4, is_transmission=True
)
ws.set_knm_info(
"P4i_P2o", nr_from=ws.nr4, 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_carrier(self, ws):
self._fill_matrix(ws, ws.sim.carrier, ws.carrier.connections)
def _fill_signal(self, ws):
self._fill_matrix(ws, ws.sim.signal, ws.signal.connections)
def _fill_matrix(self, ws, mtx, connections):
for freq in mtx.optical_frequencies.frequencies:
for idx, K in zip(
(
connections.P1i_P3o_idx,
connections.P3i_P4o_idx,
connections.P4i_P2o_idx,
connections.P2i_P1o_idx,
),
(ws.K13, ws.K34, ws.K42, ws.K21),
):
with mtx.component_edge_fill3(
ws.owner_id,
idx,
freq.index,
freq.index,
) as mat:
mat[:] = K.data