def grating_coupler_uniform_optimized(
widths=(0.5, 0.2, 0.3),
width_grating=11,
length_taper=150,
width=0.5,
partial_etch=False,
layer=pp.LAYER.WG,
layer_partial_etch=pp.LAYER.SLAB150,
taper=None,
polarization="te",
wavelength=1500,
):
""" Grating coupler uniform (not focusing)
Args:
widths: of each teeth
width_grating: 11
length_taper: 150
width: 0.5
partial_etch: False
.. plot::
:include-source:
import pp
c = pp.c.grating_coupler_uniform_optimized()
pp.plotgds(c)
"""
# returns a fiber grating
c = Component()
x = 0
if partial_etch:
partetch_overhang = 5
# make the etched areas (opposite to teeth)
for i, wt in enumerate(widths):
if i % 2 == 1:
_compass = pp.c.compass(
size=[wt, width_grating + partetch_overhang * 2],
layer=layer_partial_etch,
)
cgrating = c.add_ref(_compass)
cgrating.x += x + wt / 2
x += wt
# draw the deep etched square around the grating
xgrating = np.sum(widths)
deepbox = c.add_ref(pp.c.compass(size=[xgrating, width_grating], layer=layer))
deepbox.movex(xgrating / 2)
else:
for i, wt in enumerate(widths):
if i % 2 == 0:
cgrating = c.add_ref(
pp.c.compass(size=[wt, width_grating], layer=layer)
)
cgrating.x += x + wt / 2
x += wt
# make the taper
if taper is None:
taper = pp.c.taper(
length=length_taper,
width1=width,
width2=width_grating,
port=None,
layer=layer,
)
taper_ref = c.add_ref(taper)
taper_ref.xmax = 0
port = taper_ref.ports.get("W0") or taper_ref.ports.get("1")
c.polarization = polarization
c.wavelength = wavelength
c.add_port(port=taper_ref.ports[port.name], name="W0")
pp.assert_grating_coupler_properties(c)
return c
def grating_coupler_uniform(
num_teeth: int = 20,
period: float = 0.75,
fill_factor: float = 0.5,
width_grating: float = 11.0,
length_taper: float = 150.0,
width: float = 0.5,
partial_etch: bool = False,
layer: Tuple[int, int] = pp.LAYER.WG,
layer_partial_etch: Tuple[int, int] = pp.LAYER.SLAB150,
polarization="te",
wavelength=1500,
) -> Component:
"""Grating coupler uniform
Args:
num_teeth: 20
period: 0.75
fill_factor: 0.5
width_grating: 11
length_taper: 150
width: 0.5
partial_etch: False
.. plot::
:include-source:
import pp
c = pp.c.grating_coupler_uniform()
pp.plotgds(c)
"""
# returns a fiber grating
G = Component()
if partial_etch:
partetch_overhang = 5
_compass = compass(
size=[period * (1 - fill_factor), width_grating + partetch_overhang * 2],
layer=layer_partial_etch,
)
# make the etched areas (opposite to teeth)
for i in range(num_teeth):
cgrating = G.add_ref(_compass)
cgrating.x += i * period
# draw the deep etched square around the grating
deepbox = G.add_ref(
compass(size=[num_teeth * period, width_grating], layer=layer)
)
deepbox.movex(num_teeth * period / 2)
else:
for i in range(num_teeth):
cgrating = G.add_ref(
compass(size=[period * fill_factor, width_grating], layer=layer)
)
cgrating.x += i * period
# make the taper
tgrating = G.add_ref(
taper(
length=length_taper,
width1=width_grating,
width2=width,
port=None,
layer=layer,
)
)
tgrating.xmin = cgrating.xmax
G.add_port(port=tgrating.ports["2"], name="W0")
G.polarization = polarization
G.wavelength = wavelength
G.rotate(180)
return G
