def crossing_arm(
wg_width: float = 0.5,
r1: float = 3.0,
r2: float = 1.1,
w: float = 1.2,
L: float = 3.4,
) -> Component:
"""arm of a crossing"""
c = pp.Component()
_ellipse = ellipse(radii=(r1, r2), layer=LAYER.SLAB150).ref()
c.add(_ellipse)
c.absorb(_ellipse)
a = pp.drc.snap_to_1nm_grid(L + w / 2)
h = wg_width / 2
taper_pts = [
(-a, h),
(-w / 2, w / 2),
(w / 2, w / 2),
(a, h),
(a, -h),
(w / 2, -w / 2),
(-w / 2, -w / 2),
(-a, -h),
]
c.add_polygon(taper_pts, layer=LAYER.WG)
c.add_port(name="W0",
midpoint=(-a, 0),
orientation=180,
width=wg_width,
layer=LAYER.WG)
c.add_port(name="E0",
midpoint=(a, 0),
orientation=0,
width=wg_width,
layer=LAYER.WG)
return c
def crossing_arm(wg_width=0.5, r1=3.0, r2=1.1, w=1.2, L=3.4):
"""
"""
cmp = pp.Component()
_ellipse = ellipse(radii=(r1, r2), layer=LAYER.SLAB150).ref()
cmp.add(_ellipse)
cmp.absorb(_ellipse)
a = L + w / 2
h = wg_width / 2
taper_pts = [
(-a, h),
(-w / 2, w / 2),
(w / 2, w / 2),
(a, h),
(a, -h),
(w / 2, -w / 2),
(-w / 2, -w / 2),
(-a, -h),
]
cmp.add_polygon(taper_pts, layer=LAYER.WG)
cmp.add_port(name="W0",
midpoint=(-a, 0),
orientation=180,
width=wg_width,
layer=LAYER.WG)
cmp.add_port(name="E0",
midpoint=(a, 0),
orientation=0,
width=wg_width,
layer=LAYER.WG)
return cmp
def crossing_etched(
wg_width=0.5,
r1=3.0,
r2=1.1,
w=1.2,
L=3.4,
layer_wg=LAYER.WG,
layer_slab=LAYER.SLAB150,
):
"""
Waveguide crossing:
- The full crossing has to be on WG layer (to start with a 220nm slab)
- Then we etch the ellipses down to 150nm slabs and we keep linear taper at 220nm. What we write is what we etch on this step
"""
# Draw the ellipses
c = pp.Component()
_ellipse1 = ellipse(radii=(r1, r2), layer=layer_wg).ref()
_ellipse2 = ellipse(radii=(r2, r1), layer=layer_wg).ref()
c.add(_ellipse1)
c.add(_ellipse2)
c.absorb(_ellipse1)
c.absorb(_ellipse2)
#
a = L + w / 2
h = wg_width / 2
taper_cross_pts = [
(-a, h),
(-w / 2, w / 2),
(-h, a),
(h, a),
(w / 2, w / 2),
(a, h),
(a, -h),
(w / 2, -w / 2),
(h, -a),
(-h, -a),
(-w / 2, -w / 2),
(-a, -h),
]
tapers_poly = c.add_polygon(taper_cross_pts, layer=layer_wg)
b = a - 0.1 # To make sure we get 4 distinct polygons when doing bool ops
tmp_polygon = [(-b, b), (b, b), (b, -b), (-b, -b)]
polys_etch = gdspy.fast_boolean([tmp_polygon],
tapers_poly,
"not",
layer=layer_slab)
c.add(polys_etch)
positions = [(a, 0), (0, a), (-a, 0), (0, -a)]
angles = [0, 90, 180, 270]
i = 0
for p, angle in zip(positions, angles):
c.add_port(
name="tmp{}".format(i),
midpoint=p,
orientation=angle,
width=wg_width,
layer=layer_wg,
)
i += 1
c = pp.port.rename_ports_by_orientation(c)
return c