from __future__ import annotations
import gdsfactory as gf
from gdsfactory.component import Component
from gdsfactory.components.taper import taper as taper_function
from gdsfactory.typings import ComponentFactory, CrossSectionSpec
[docs]
@gf.cell
def mmi1x2(
width: float | None = None,
width_taper: float = 1.0,
length_taper: float = 10.0,
length_mmi: float = 5.5,
width_mmi: float = 2.5,
gap_mmi: float = 0.25,
taper: ComponentFactory = taper_function,
cross_section: CrossSectionSpec = "xs_sc",
**kwargs,
) -> Component:
r"""1x2 MultiMode Interferometer (MMI).
Args:
width: input and output straight width. Defaults to cross_section width.
width_taper: interface between input straights and mmi region.
length_taper: into the mmi region.
length_mmi: in x direction.
width_mmi: in y direction.
gap_mmi: gap between tapered wg.
taper: taper function.
cross_section: specification (CrossSection, string or dict).
.. code::
length_mmi
<------>
________
| |
| \__
| __ o2
__/ /_ _ _ _
o1 __ | _ _ _ _| gap_mmi
\ \__
| __ o3
| /
|________|
<->
length_taper
"""
c = Component()
gap_mmi = gf.snap.snap_to_grid(gap_mmi, grid_factor=2)
x = gf.get_cross_section(cross_section, **kwargs)
width = width or x.width
_taper = taper(
length=length_taper,
width1=width,
width2=width_taper,
cross_section=x,
)
delta_width = width_mmi - width
y = width_mmi / 2
c.add_polygon([(0, -y), (length_mmi, -y), (length_mmi, y), (0, y)], layer=x.layer)
for section in x.sections[1:]:
layer = section.layer
y = section.width / 2 + delta_width / 2
c.add_polygon(
[
(-delta_width, -y),
(length_mmi + delta_width, -y),
(length_mmi + delta_width, y),
(-delta_width, y),
],
layer=layer,
)
x.add_bbox(c)
a = gap_mmi / 2 + width_taper / 2
ports = [
gf.Port(
"o1",
orientation=180,
center=(0, 0),
width=width_taper,
layer=x.layer,
cross_section=x,
),
gf.Port(
"o2",
orientation=0,
center=(+length_mmi, +a),
width=width_taper,
layer=x.layer,
cross_section=x,
),
gf.Port(
"o3",
orientation=0,
center=(+length_mmi, -a),
width=width_taper,
layer=x.layer,
cross_section=x,
),
]
for port in ports:
taper_ref = c << _taper
taper_ref.connect(port="o2", destination=port)
c.add_port(name=port.name, port=taper_ref.ports["o1"])
c.absorb(taper_ref)
return c
if __name__ == "__main__":
import gdsfactory as gf
c = gf.components.mmi1x2(cross_section="xs_rc_bbox")
# c = gf.components.mmi1x2(cross_section="xs_rc")
# print(c.xmin)
# c.xmin = 0
# print(c.xmin)
c.show(show_ports=True)
