masque/examples/tutorial/phc.py

252 lines
9.1 KiB
Python

from typing import Tuple, Sequence
import numpy
from numpy import pi
from masque import layer_t, Pattern, SubPattern, Label
from masque.shapes import Polygon, Circle
from masque.builder import Device, Port
from masque.library import Library, DeviceLibrary
from masque.file.gdsii import writefile
import pcgen
import basic
def perturbed_l3(
lattice_constant: float,
hole: Pattern,
trench_dose: float = 1.0,
trench_layer: layer_t = (1, 0),
shifts_a: Sequence[float] = (0.15, 0, 0.075),
shifts_r: Sequence[float] = (1.0, 1.0, 1.0),
xy_size: Tuple[int, int] = (10, 10),
perturbed_radius: float = 1.1,
trench_width: float = 1200,
) -> Device:
"""
Generate a `Device` representing a perturbed L3 cavity.
Args:
lattice_constant: Distance between nearest neighbor holes
hole: `Pattern` object containing a single hole
trench_dose: Dose for the trenches. Default 1.0. (Hole dose is 1.0.)
trench_layer: Layer for the trenches, default `(1, 0)`.
shifts_a: passed to `pcgen.l3_shift`; specifies lattice constant
(1 - multiplicative factor) for shifting holes adjacent to
the defect (same row). Default `(0.15, 0, 0.075)` for first,
second, third holes.
shifts_r: passed to `pcgen.l3_shift`; specifies radius for perturbing
holes adjacent to the defect (same row). Default 1.0 for all holes.
Provided sequence should have same length as `shifts_a`.
xy_size: `(x, y)` number of mirror periods in each direction; total size is
`2 * n + 1` holes in each direction. Default (10, 10).
perturbed_radius: radius of holes perturbed to form an upwards-driected beam
(multiplicative factor). Default 1.1.
trench width: Width of the undercut trenches. Default 1200.
Returns:
`Device` object representing the L3 design.
"""
xyr = pcgen.l3_shift_perturbed_defect(mirror_dims=xy_size,
perturbed_radius=perturbed_radius,
shifts_a=shifts_a,
shifts_r=shifts_r)
pat = Pattern(f'L3p-a{lattice_constant:g}rp{perturbed_radius:g}')
pat.subpatterns += [SubPattern(hole,
offset=(lattice_constant * x,
lattice_constant * y),
scale=r)
for x, y, r in xyr]
bounds = pat.get_bounds()
assert(bounds is not None)
min_xy, max_xy = bounds
trench_dx = max_xy[0] - min_xy[0]
pat.shapes += [
Polygon.rect(ymin=max_xy[1], xmin=min_xy[0], lx=trench_dx, ly=trench_width,
layer=trench_layer, dose=trench_dose),
Polygon.rect(ymax=min_xy[1], xmin=min_xy[0], lx=trench_dx, ly=trench_width,
layer=trench_layer, dose=trench_dose),
]
extent = lattice_constant * xy_size[0]
ports = {
'input': Port((-extent, 0), rotation=0, ptype='pcwg'),
'output': Port((extent, 0), rotation=pi, ptype='pcwg'),
}
return Device(pat, ports)
def waveguide(
lattice_constant: float,
hole: Pattern,
length: int,
mirror_periods: int,
) -> Device:
"""
Generate a `Device` representing a photonic crystal line-defect waveguide.
Args:
lattice_constant: Distance between nearest neighbor holes
hole: `Pattern` object containing a single hole
length: Distance (number of mirror periods) between the input and output ports.
Ports are placed at lattice sites.
mirror_periods: Number of hole rows on each side of the line defect
Returns:
`Device` object representing the waveguide.
"""
xy = pcgen.waveguide(length=length, num_mirror=mirror_periods)
pat = Pattern(f'_wg-a{lattice_constant:g}l{length}')
pat.subpatterns += [SubPattern(hole, offset=(lattice_constant * x,
lattice_constant * y))
for x, y in xy]
extent = lattice_constant * length / 2
ports = {
'left': Port((-extent, 0), rotation=0, ptype='pcwg'),
'right': Port((extent, 0), rotation=pi, ptype='pcwg'),
}
return Device(pat, ports)
def bend(
lattice_constant: float,
hole: Pattern,
mirror_periods: int,
) -> Device:
"""
Generate a `Device` representing a 60-degree counterclockwise bend in a photonic crystal
line-defect waveguide.
Args:
lattice_constant: Distance between nearest neighbor holes
hole: `Pattern` object containing a single hole
mirror_periods: Minimum number of mirror periods on each side of the line defect.
Returns:
`Device` object representing the waveguide bend.
Ports are named 'left' (input) and 'right' (output).
"""
xy = pcgen.wgbend(num_mirror=mirror_periods)
pat= Pattern(f'_wgbend-a{lattice_constant:g}l{mirror_periods}')
pat.subpatterns += [SubPattern(hole, offset=(lattice_constant * x,
lattice_constant * y))
for x, y in xy]
extent = lattice_constant * mirror_periods
ports = {
'left': Port((-extent, 0), rotation=0, ptype='pcwg'),
'right': Port((extent / 2,
extent * numpy.sqrt(3) / 2), rotation=pi * 4 / 3, ptype='pcwg'),
}
return Device(pat, ports)
def y_splitter(
lattice_constant: float,
hole: Pattern,
mirror_periods: int,
) -> Device:
"""
Generate a `Device` representing a photonic crystal line-defect waveguide y-splitter.
Args:
lattice_constant: Distance between nearest neighbor holes
hole: `Pattern` object containing a single hole
mirror_periods: Minimum number of mirror periods on each side of the line defect.
Returns:
`Device` object representing the y-splitter.
Ports are named 'in', 'top', and 'bottom'.
"""
xy = pcgen.y_splitter(num_mirror=mirror_periods)
pat = Pattern(f'_wgsplit_half-a{lattice_constant:g}l{mirror_periods}')
pat.subpatterns += [SubPattern(hole, offset=(lattice_constant * x,
lattice_constant * y))
for x, y in xy]
extent = lattice_constant * mirror_periods
ports = {
'in': Port((-extent, 0), rotation=0, ptype='pcwg'),
'top': Port((extent / 2,
extent * numpy.sqrt(3) / 2), rotation=pi * 4 / 3, ptype='pcwg'),
'bot': Port((extent / 2,
-extent * numpy.sqrt(3) / 2), rotation=pi * 2 / 3, ptype='pcwg'),
}
return Device(pat, ports)
def label_ports(device: Device, layer: layer_t = (3, 0)) -> Device:
"""
Place a text label at each port location, specifying the port data.
This can be used to debug port locations or to automatically generate ports
when reading in a GDS file.
Args:
device: The device which is to have its ports labeled.
layer: The layer on which the labels will be placed.
Returns:
`device` is returned (and altered in-place)
"""
for name, port in device.ports.items():
angle_deg = numpy.rad2deg(port.rotation) if port.rotation is not None else numpy.inf
device.pattern.labels += [
Label(string=f'{name} (angle {angle_deg:g})', layer=layer, offset=port.offset)
]
return device
def main():
a = 512
radius = a / 2 * 0.75
smile = basic.smile(radius)
hole = basic.hole(radius)
wg10 = label_ports(waveguide(lattice_constant=a, hole=hole, length=10, mirror_periods=5))
wg05 = label_ports(waveguide(lattice_constant=a, hole=hole, length=5, mirror_periods=5))
wg28 = label_ports(waveguide(lattice_constant=a, hole=hole, length=28, mirror_periods=5))
bend0 = label_ports(bend(lattice_constant=a, hole=hole, mirror_periods=5))
l3cav = label_ports(perturbed_l3(lattice_constant=a, hole=smile, xy_size=(4, 10)))
ysplit = label_ports(y_splitter(lattice_constant=a, hole=hole, mirror_periods=5))
dev = Device(name='my_bend', ports={})
dev.place(wg10, offset=(0, 0), port_map={'left': 'in', 'right': 'signal'})
dev.plug(wg10, {'signal': 'left'})
dev.plug(ysplit, {'signal': 'in'}, {'top': 'signal1', 'bot': 'signal2'})
dev.plug(wg05, {'signal1': 'left'})
dev.plug(wg05, {'signal2': 'left'})
dev.plug(bend0, {'signal1': 'right'})
dev.plug(bend0, {'signal2': 'left'})
dev.plug(wg10, {'signal1': 'left'})
dev.plug(l3cav, {'signal1': 'input'})
dev.plug(wg10, {'signal1': 'left'})
dev.plug(wg28, {'signal2': 'left'})
dev.plug(bend0, {'signal1': 'right'})
dev.plug(bend0, {'signal2': 'left'})
dev.plug(wg05, {'signal1': 'left'})
dev.plug(wg05, {'signal2': 'left'})
dev.plug(ysplit, {'signal1': 'bot', 'signal2': 'top'}, {'in': 'signal_out'})
dev.plug(wg10, {'signal_out': 'left'})
writefile(dev.pattern, 'phc.gds', 1e-9, 1e-3)
dev.pattern.visualize()
if __name__ == '__main__':
main()