from __future__ import annotations
import gdsfactory as gf
from gdsfactory.component import Component
from gdsfactory.components.bend_euler import bend_euler
from gdsfactory.components.coupler import coupler as coupler_function
from gdsfactory.components.straight import straight as straight_function
from gdsfactory.components.taper import taper as taper_function
from gdsfactory.typings import ComponentFactory
[docs]
@gf.cell
def mzit(
w0: float = 0.5,
w1: float = 0.45,
w2: float = 0.55,
dy: float = 2.0,
delta_length: float = 10.0,
length: float = 1.0,
coupler_length1: float = 5.0,
coupler_length2: float = 10.0,
coupler_gap1: float = 0.2,
coupler_gap2: float = 0.3,
taper: ComponentFactory = taper_function,
taper_length: float = 5.0,
bend90: ComponentFactory = bend_euler,
straight: ComponentFactory = straight_function,
coupler1: ComponentFactory | None = coupler_function,
coupler2: ComponentFactory = coupler_function,
cross_section: str = "xs_sc",
) -> Component:
r"""Mzi tolerant to fabrication variations.
based on Yufei Xing thesis
http://photonics.intec.ugent.be/publications/PhD.asp?ID=250
Args:
w1: narrow waveguide width (um).
w2: wide waveguide width (um).
dy: port to port vertical spacing.
delta_length: length difference between arms (um).
length: shared length for w1 and w2.
coupler_length1: length of coupler1.
coupler_length2: length of coupler2.
coupler_gap1: coupler1.
coupler_gap2: coupler2.
taper: taper spec.
taper_length: from w0 to w1.
bend90: bend spec.
straight: spec.
coupler1: coupler1 spec (optional).
coupler2: coupler2 spec.
.. code::
cp1
4 2 __ __ 3___w0_t2 _w2___
\ / \
\ length1 / |
============== gap1 |
/ \ |
__/ \_____w0___t1 _w1 |
3 1 4 \ |
| |
2 2 | |
__ __w0____t1____w1___/ |
\ / |
\ length2 / |
============== gap2 |
/ \ | |
__/ \ E0_w0__t2 __w1______/
1 1
cp2
"""
c = gf.Component()
xs1 = gf.get_cross_section(cross_section, width=w1)
xs2 = gf.get_cross_section(cross_section, width=w2)
cp2 = c << coupler2(
length=coupler_length2,
gap=coupler_gap2,
dy=dy,
cross_section=cross_section,
)
# inner arm (w1)
t1 = c << taper(
width1=w0,
width2=w1,
length=taper_length,
cross_section=cross_section,
)
t1.connect("o1", cp2.ports["o3"])
b1t = c << bend90(
cross_section=xs1,
)
b1b = c << bend90(
cross_section=xs1,
)
b1b.connect("o1", t1.ports["o2"])
b1t.connect("o1", b1b.ports["o2"])
t3b = c << taper(
width1=w1,
width2=w2,
length=taper_length,
cross_section=cross_section,
)
t3b.connect("o1", b1t.ports["o2"])
wgs2 = c << straight(length=length, cross_section=xs2)
wgs2.connect("o1", t3b.ports["o2"])
t20i = c << taper(
width1=w2,
width2=w0,
length=taper_length,
cross_section=cross_section,
)
t20i.connect("o1", wgs2.ports["o2"])
# outer_arm (w2)
t2 = c << taper(
width1=w0,
width2=w2,
length=taper_length,
cross_section=cross_section,
)
t2.connect("o1", cp2.ports["o4"])
dx = (delta_length - 2 * dy) / 2
assert (
delta_length >= 4 * dy
), f"`delta_length`={delta_length} needs to be at least {4*dy}"
wg2b = c << straight(length=dx, cross_section=xs2)
wg2b.connect("o1", t2.ports["o2"])
b2 = bend90(cross_section=xs2)
b2t = c << b2
b2b = c << b2
wy = straight(length=2 * dy, cross_section=xs2)
wx = straight(length=dx, cross_section=xs2)
b2b.connect("o1", wg2b.ports["o2"])
# vertical straight
wg2y = c << wy
wg2y.connect("o1", b2b.ports["o2"])
b2t.connect("o1", wg2y.ports["o2"])
wg2t = c << wx
wg2t.connect("o1", b2t.ports["o2"])
t3t = c << taper(
width1=w2,
width2=w1,
length=taper_length,
cross_section=cross_section,
)
t3t.connect("o1", wg2t.ports["o2"])
wgs1 = c << straight(length=length, cross_section=xs1)
wgs1.connect("o1", t3t.ports["o2"])
t20o = c << taper(
width1=w1,
width2=w0,
length=taper_length,
cross_section=cross_section,
)
t20o.connect("o1", wgs1.ports["o2"])
if coupler1 is not None:
cp1 = c << coupler1(
length=coupler_length1,
gap=coupler_gap1,
dy=dy,
cross_section=cross_section,
)
cp1.connect("o3", t20o.ports["o2"])
cp1.connect("o4", t20i.ports["o2"])
c.add_port("W3", port=cp1.ports["o2"])
c.add_port("W2", port=cp1.ports["o1"])
else:
c.add_port("W3", port=t20o.ports["o2"])
c.add_port("W2", port=t20i.ports["o2"])
c.add_port("o2", port=cp2.ports["o2"])
c.add_port("o1", port=cp2.ports["o1"])
c.auto_rename_ports()
return c
if __name__ == "__main__":
c = mzit()
# c = mzit(coupler1=None)
# c = mzit(delta_length=20, layer=(2, 0))
# c = mzit(delta_length=20, cross_section="xs_rc_bbox")
# c = mzit(delta_length=20, coupler_gap1=0.1, coupler_gap2=0.5)
# c = mzit(delta_length=20, coupler_gap1=0.5, coupler_gap2=0.1)
# c = mzit(coupler_length1=200)
c.show(show_ports=True)
