from __future__ import annotations
import numpy as np
import gdsfactory as gf
from gdsfactory.components.bend_s import bend_s as bend_s_function
from gdsfactory.components.mmi1x2 import mmi1x2
from gdsfactory.components.mmi2x2 import mmi2x2
from gdsfactory.typings import ComponentSpec, CrossSectionSpec, Float2
[docs]
@gf.cell
def splitter_tree(
coupler: ComponentSpec = mmi1x2,
noutputs: int = 4,
spacing: Float2 = (90.0, 50.0),
bend_s: ComponentSpec | None = bend_s_function,
bend_s_xsize: float | None = None,
cross_section: CrossSectionSpec = "xs_sc",
) -> gf.Component:
"""Tree of power splitters.
Args:
coupler: coupler factory.
noutputs: number of outputs.
spacing: x, y spacing between couplers.
bend_s: Sbend function for termination.
bend_s_xsize: xsize for the sbend.
cross_section: cross_section.
.. code::
__|
__| |__
_| |__
|__ dy
dx
"""
c = gf.Component()
dx, dy = spacing
coupler = gf.get_component(coupler)
coupler_ports_west = coupler.get_ports_list(port_type="optical", orientation=180)
coupler_ports_east = coupler.get_ports_list(port_type="optical", orientation=0)
e1_port_name = coupler_ports_east[0].name
e0_port_name = coupler_ports_east[1].name
w0_port_name = coupler_ports_west[0].name
if bend_s:
dy_coupler_ports = abs(
coupler.ports[e0_port_name].center[1]
- coupler.ports[e1_port_name].center[1]
)
bend_s_ysize = dy / 4 - dy_coupler_ports / 2
bend_s_xsize = bend_s_xsize or dx
bend_s = gf.get_component(
bend_s,
cross_section=cross_section,
size=(bend_s_xsize, bend_s_ysize),
)
cols = int(np.log2(noutputs))
i = 0
for col in range(cols):
ncouplers = int(2**col)
y0 = -0.5 * dy * 2 ** (cols - 1)
for row in range(ncouplers):
x = col * dx
y = y0 + (row + 0.5) * dy * 2 ** (cols - col - 1)
coupler_ref = c.add_ref(coupler, alias=f"coupler_{col}_{row}")
coupler_ref.move((x, y))
if col == 0:
for port in coupler_ref.get_ports_list():
if port.name not in [e0_port_name, e1_port_name]:
c.add_port(name=f"{port.name}_{col}_{i}", port=port)
i += 1
if col > 0:
if row % 2 == 0:
port_name = e0_port_name
if row % 2 == 1:
port_name = e1_port_name
c.add(
gf.routing.get_route(
c.named_references[f"coupler_{col-1}_{row//2}"].ports[
port_name
],
coupler_ref.ports["o1"],
cross_section=cross_section,
).references
)
if cols > col > 0:
for port in coupler_ref.get_ports_list():
if port.name not in [
"o1",
e0_port_name,
e1_port_name,
w0_port_name,
]:
c.add_port(name=f"{port.name}_{col}_{i}", port=port)
i += 1
if col == cols - 1 and bend_s is None:
for port in coupler_ref.get_ports_list():
if port.name in [e1_port_name, e0_port_name]:
c.add_port(name=f"{port.name}_{col}_{i}", port=port)
i += 1
if col == cols - 1 and bend_s:
btop = c << bend_s
bbot = c << bend_s
bbot.mirror()
btop.connect("o1", coupler_ref.ports[e1_port_name])
bbot.connect("o1", coupler_ref.ports[e0_port_name])
port = btop.ports["o2"]
c.add_port(name=f"{port.name}_{col}_{i}", port=port)
i += 1
port = bbot.ports["o2"]
c.add_port(name=f"{port.name}_{col}_{i}", port=port)
i += 1
return c
def test_splitter_tree_ports() -> None:
c = splitter_tree(
coupler=mmi2x2,
noutputs=4,
)
assert len(c.ports) == 8, len(c.ports)
def test_splitter_tree_ports_no_sbend() -> None:
c = splitter_tree(
coupler=mmi2x2,
noutputs=4,
bend_s=None,
)
assert len(c.ports) == 8, len(c.ports)
if __name__ == "__main__":
test_splitter_tree_ports()
test_splitter_tree_ports_no_sbend()
import gdsfactory as gf
# c = splitter_tree(
# coupler=partial(mmi2x2, gap_mmi=2.0, width_mmi=5.0),
# # noutputs=128 * 2,
# # noutputs=2 ** 3,
# noutputs=2**2,
# # bend_s=None,
# # dy=100.0,
# # layer=(2, 0),
# )
c = splitter_tree(
noutputs=2**2,
spacing=(120.0, 50.0),
# bend_length=30,
# bend_s=None,
cross_section="xs_rc2",
)
c.show(show_ports=True)
# print(len(c.ports))
# for port in c.get_ports_list():
# print(port)
