"""Bends with grating couplers inside the spiral.
maybe: need to add grating coupler loopback as well
"""
from __future__ import annotations
import numpy as np
from numpy import float64
import gdsfactory as gf
from gdsfactory.cell import cell
from gdsfactory.component import Component
from gdsfactory.components.bend_euler import bend_euler
from gdsfactory.routing.manhattan import round_corners
from gdsfactory.typings import ComponentSpec, CrossSectionSpec
def get_bend_port_distances(bend: Component) -> tuple[float64, float64]:
"""Returns distance between bend ports."""
p0, p1 = bend.ports.values()
return abs(p0.x - p1.x), abs(p0.y - p1.y)
[docs]
@cell
def spiral_external_io(
N: int = 6,
x_inner_length_cutback: float = 300.0,
x_inner_offset: float = 0.0,
y_straight_inner_top: float = 0.0,
xspacing: float = 3.0,
yspacing: float = 3.0,
bend: ComponentSpec = bend_euler,
length: float | None = None,
cross_section: CrossSectionSpec = "xs_sc",
with_inner_ports: bool = False,
y_straight_outer_offset: float = 0.0,
inner_loop_spacing_offset: float = 0.0,
mirror_straight: bool = False,
**kwargs,
) -> Component:
"""Returns spiral with input and output ports outside the spiral.
Args:
N: number of loops.
x_inner_length_cutback: x inner length.
x_inner_offset: x inner offset.
y_straight_inner_top: y straight inner top.
xspacing: center to center x-spacing.
yspacing: center to center y-spacing.
bend: function.
length: length in um, it is the approximates total length.
cross_section: spec.
with_inner_ports: if True, removes the internal S-bend and exposes new ports
y_straight_outer_offset: amount to add/remove to the last points at the outer output of the spiral
inner_loop_spacing_offset: extra difference between the inner ports
mirror_straight: if True, mirrors the straight cross section in round_corners (can help when xs is asymmetric)
kwargs: cross_section settings.
"""
if length:
x_inner_length_cutback = length / (4 * (N - 1))
y_straight_inner_top += 5
x_inner_length_cutback += x_inner_offset
xs = gf.get_cross_section(cross_section, **kwargs)
_bend180 = gf.get_component(bend, angle=180, cross_section=xs)
_bend90 = gf.get_component(bend, angle=90, cross_section=xs)
# If with_arc_floorplan is not True, the radius doesn't represent the actual size of the bend
bend_radius = _bend90.xsize - xs.width / 2
rx, ry = get_bend_port_distances(_bend90)
_, rx180 = get_bend_port_distances(_bend180) # rx180, second arg since we rotate
component = Component()
inner_loop_spacing = 2 * bend_radius + 5.0 + inner_loop_spacing_offset
# Create manhattan path going from west grating to westmost port of bend 180
x_inner_length = x_inner_length_cutback + 5.0 + xspacing
y_inner_bend = y_straight_inner_top - bend_radius - 5.0
x_inner_loop = x_inner_length - 5.0
p1 = (x_inner_loop, y_inner_bend)
p2 = (x_inner_loop + inner_loop_spacing, y_inner_bend)
_pt = np.array(p1)
pts_w = [_pt]
for i in range(N):
y1 = y_straight_inner_top + ry + (2 * i + 1) * yspacing
x2 = inner_loop_spacing + 2 * rx + x_inner_length + (2 * i + 1) * xspacing
y3 = -ry - (2 * i + 2) * yspacing
y3 += 0 if i < N - 1 else y_straight_outer_offset
x4 = -(2 * i + 1) * xspacing
if i == N - 1:
x4 = x4 - rx180 + xspacing
_pt1 = np.array([_pt[0], y1])
_pt2 = np.array([x2, _pt1[1]])
_pt3 = np.array([_pt2[0], y3])
_pt4 = np.array([x4, _pt3[1]])
_pt5 = np.array([_pt4[0], 0])
_pt = _pt5
pts_w += [_pt1, _pt2, _pt3, _pt4, _pt5]
pts_w = pts_w[:-2]
# Create manhattan path going from east grating to eastmost port of bend 180
_pt = np.array(p2)
pts_e = [_pt]
for i in range(N):
y1 = y_straight_inner_top + ry + (2 * i) * yspacing
x2 = inner_loop_spacing + 2 * rx + x_inner_length + 2 * i * xspacing
y3 = -ry - (2 * i + 1) * yspacing
y3 += 0 if i < N - 1 else y_straight_outer_offset
x4 = -2 * i * xspacing
_pt1 = np.array([_pt[0], y1])
_pt2 = np.array([x2, _pt1[1]])
_pt3 = np.array([_pt2[0], y3])
_pt4 = np.array([x4, _pt3[1]])
_pt5 = np.array([_pt4[0], 0])
_pt = _pt5
pts_e += [_pt1, _pt2, _pt3, _pt4, _pt5]
pts_e = pts_e[:-2]
# Join the two bits of paths and extrude the spiral geometry
if not with_inner_ports:
route = round_corners(
pts_w[::-1] + pts_e,
bend=bend,
cross_section=cross_section,
**kwargs,
)
component.add(route.references)
component.add_port("o2", port=route.ports[0])
component.add_port("o1", port=route.ports[1])
length = route.length
# If inner ports, do not join and layout routes separately
else:
pts_w[1][0] += bend_radius
pts_e[1][0] += bend_radius
route_west = round_corners(
pts_w[1:],
bend=bend,
cross_section=cross_section,
mirror_straight=mirror_straight,
**kwargs,
)
route_east = round_corners(
pts_e[1:],
bend=bend,
cross_section=cross_section,
mirror_straight=mirror_straight,
**kwargs,
)
component.add(route_west.references)
component.add(route_east.references)
component.add_port("o2", port=route_west.ports[0])
component.add_port("o1", port=route_east.ports[1])
component.add_port("o4", port=route_west.ports[1])
component.add_port("o3", port=route_east.ports[0])
length = route_west.length + route_east.length
component.info["length"] = length
return component
if __name__ == "__main__":
spacing = 3
c = spiral_external_io(
# N=15,
# xspacing=spacing,
# yspacing=spacing,
# with_inner_ports=True,
# x_inner_length_cutback=0,
# y_straight_inner_top=0,
# x_inner_offset=0,
)
c.show(show_ports=True)
