masque/examples/tutorial/devices.py
Jan Petykiewicz c7f3e7ee52 Remove support for dose
Since there isn't GDS/OASIS level support for dose, this can be mostly
handled by using arbitrary layers/dtypes directly. Dose scaling isn't
handled as nicely that way, but it corresponds more directly to what
gets written to file.
2023-10-15 16:18:32 -07:00

308 lines
11 KiB
Python

from typing import Tuple, Sequence, Dict
import numpy
from numpy import pi
from masque import layer_t, Pattern, SubPattern, Label
from masque.shapes import Polygon
from masque.builder import Device, Port, port_utils
from masque.file.gdsii import writefile
import pcgen
import basic_shapes
from basic_shapes import GDS_OPTS
LATTICE_CONSTANT = 512
RADIUS = LATTICE_CONSTANT / 2 * 0.75
def dev2pat(dev: Device) -> Pattern:
"""
Bake port information into the device.
This places a label at each port location on layer (3, 0) with text content
'name:ptype angle_deg'
"""
return port_utils.dev2pat(dev, layer=(3, 0))
def pat2dev(pat: Pattern) -> Device:
"""
Scans the Pattern to determine port locations. Same format as `dev2pat`
"""
return port_utils.pat2dev(pat, layers=[(3, 0)])
def perturbed_l3(
lattice_constant: float,
hole: Pattern,
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_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.
"""
# Get hole positions and radii
xyr = pcgen.l3_shift_perturbed_defect(mirror_dims=xy_size,
perturbed_radius=perturbed_radius,
shifts_a=shifts_a,
shifts_r=shifts_r)
# Build L3 cavity, using references to the provided hole pattern
pat = Pattern(f'L3p-a{lattice_constant:g}rp{perturbed_radius:g}')
pat.subpatterns += [
SubPattern(hole, scale=r,
offset=(lattice_constant * x,
lattice_constant * y))
for x, y, r in xyr]
# Add rectangular undercut aids
min_xy, max_xy = pat.get_bounds_nonempty()
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),
Polygon.rect(ymax=min_xy[1], xmin=min_xy[0], lx=trench_dx, ly=trench_width, layer=trench_layer),
]
# Ports are at outer extents of the device (with y=0)
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.
"""
# Generate hole locations
xy = pcgen.waveguide(length=length, num_mirror=mirror_periods)
# Build the pattern
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]
# Ports are at outer edges, with y=0
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).
"""
# Generate hole locations
xy = pcgen.wgbend(num_mirror=mirror_periods)
# Build the pattern
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]
# Figure out port locations.
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'.
"""
# Generate hole locations
xy = pcgen.y_splitter(num_mirror=mirror_periods)
# Build pattern
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]
# Determine port locations
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 main(interactive: bool = True):
# Generate some basic hole patterns
smile = basic_shapes.smile(RADIUS)
hole = basic_shapes.hole(RADIUS)
# Build some devices
a = LATTICE_CONSTANT
wg10 = waveguide(lattice_constant=a, hole=hole, length=10, mirror_periods=5).rename('wg10')
wg05 = waveguide(lattice_constant=a, hole=hole, length=5, mirror_periods=5).rename('wg05')
wg28 = waveguide(lattice_constant=a, hole=hole, length=28, mirror_periods=5).rename('wg28')
bend0 = bend(lattice_constant=a, hole=hole, mirror_periods=5).rename('bend0')
ysplit = y_splitter(lattice_constant=a, hole=hole, mirror_periods=5).rename('ysplit')
l3cav = perturbed_l3(lattice_constant=a, hole=smile, xy_size=(4, 10)).rename('l3cav') # uses smile :)
# Autogenerate port labels so that GDS will also contain port data
for device in [wg10, wg05, wg28, l3cav, ysplit, bend0]:
dev2pat(device)
#
# Build a circuit
#
circ = Device(name='my_circuit', ports={})
# Start by placing a waveguide. Call its ports "in" and "signal".
circ.place(wg10, offset=(0, 0), port_map={'left': 'in', 'right': 'signal'})
# Extend the signal path by attaching the "left" port of a waveguide.
# Since there is only one other port ("right") on the waveguide we
# are attaching (wg10), it automatically inherits the name "signal".
circ.plug(wg10, {'signal': 'left'})
# Attach a y-splitter to the signal path.
# Since the y-splitter has 3 ports total, we can't auto-inherit the
# port name, so we have to specify what we want to name the unattached
# ports. We can call them "signal1" and "signal2".
circ.plug(ysplit, {'signal': 'in'}, {'top': 'signal1', 'bot': 'signal2'})
# Add a waveguide to both signal ports, inheriting their names.
circ.plug(wg05, {'signal1': 'left'})
circ.plug(wg05, {'signal2': 'left'})
# Add a bend to both ports.
# Our bend's ports "left" and "right" refer to the original counterclockwise
# orientation. We want the bends to turn in opposite directions, so we attach
# the "right" port to "signal1" to bend clockwise, and the "left" port
# to "signal2" to bend counterclockwise.
# We could also use `mirrored=(True, False)` to mirror one of the devices
# and then use same device port on both paths.
circ.plug(bend0, {'signal1': 'right'})
circ.plug(bend0, {'signal2': 'left'})
# We add some waveguides and a cavity to "signal1".
circ.plug(wg10, {'signal1': 'left'})
circ.plug(l3cav, {'signal1': 'input'})
circ.plug(wg10, {'signal1': 'left'})
# "signal2" just gets a single of equivalent length
circ.plug(wg28, {'signal2': 'left'})
# Now we bend both waveguides back towards each other
circ.plug(bend0, {'signal1': 'right'})
circ.plug(bend0, {'signal2': 'left'})
circ.plug(wg05, {'signal1': 'left'})
circ.plug(wg05, {'signal2': 'left'})
# To join the waveguides, we attach a second y-junction.
# We plug "signal1" into the "bot" port, and "signal2" into the "top" port.
# The remaining port gets named "signal_out".
# This operation would raise an exception if the ports did not line up
# correctly (i.e. they required different rotations or translations of the
# y-junction device).
circ.plug(ysplit, {'signal1': 'bot', 'signal2': 'top'}, {'in': 'signal_out'})
# Finally, add some more waveguide to "signal_out".
circ.plug(wg10, {'signal_out': 'left'})
# We can visualize the design. Usually it's easier to just view the GDS.
if interactive:
print('Visualizing... this step may be slow')
circ.pattern.visualize()
# We can also add text labels for our circuit's ports.
# They will appear at the uppermost hierarchy level, while the individual
# device ports will appear further down, in their respective cells.
dev2pat(circ)
# Write out to GDS
writefile(circ.pattern, 'circuit.gds', **GDS_OPTS)
if __name__ == '__main__':
main()