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_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. """ # 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, 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), ] # 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()