def get_shapely_object(self):
splitter1 = MMI(origin=self.origin, angle=self.angle, wg_width=self.width, length=self.splitter_length,
width=self.splitter_width, num_inputs=1, num_outputs=2)
print(splitter1.output_ports)
upper_wg = Waveguide.make_at_port(splitter1.left_branch_port)
upper_wg.add_bend(np.deg2rad(90), self.bend_radius)
upper_wg.add_straight_segment(self.upper_vertical_length)
upper_wg.add_bend(np.deg2rad(-90), self.bend_radius)
upper_wg.add_straight_segment(self.horizontal_length)
upper_wg.add_bend(np.deg2rad(-90), self.bend_radius)
upper_wg.add_straight_segment(self.upper_vertical_length)
upper_wg.add_bend(np.deg2rad(90), self.bend_radius)
lower_wg = Waveguide.make_at_port(splitter1.right_branch_port)
lower_wg.add_bend(np.deg2rad(-90), self.bend_radius)
lower_wg.add_straight_segment(self.lower_vertical_length)
lower_wg.add_bend(np.deg2rad(90), self.bend_radius)
lower_wg.add_straight_segment(self.horizontal_length)
lower_wg.add_bend(np.deg2rad(90), self.bend_radius)
lower_wg.add_straight_segment(self.lower_vertical_length)
lower_wg.add_bend(np.deg2rad(-90), self.bend_radius)
splitter2 = MMI(origin=[self.origin[0] + self.dev_width, self.origin[1]], angle=self.angle + np.pi,
wg_width=self.width, length=self.splitter_length,
width=self.splitter_width, num_inputs=1, num_outputs=2)
print(splitter2.input_ports)
return geometric_union([splitter1, splitter2, upper_wg, lower_wg])
def example_mmi():
from gdshelpers.parts.splitter import MMI
from gdshelpers.parts.waveguide import Waveguide
# mp.quiet(True)
mmi = MMI((0, 0), 0, 1.3, length=42, width=7.7, num_inputs=2, num_outputs=2) # , taper_width=3)
# mmi = Splitter((0, 0), 0, wg_width_root=1.15, sep=5, total_length=40)
mmi.input_ports = [mmi.input_ports[0]]
mmi.output_ports = [mmi.left_branch_port, mmi.right_branch_port]
wgs = [Waveguide.make_at_port(port).add_straight_segment(4) for port in [mmi.input_ports[0]] + mmi.output_ports]
sim = Simulation(resolution=15, reduce_to_2d=True)
sim.add_structure([mmi], wgs, mp.Medium(index=1.666), z_min=0, z_max=.33)
source = sim.add_eigenmode_source(mp.GaussianSource(wavelength=1.55, width=2),
mmi.input_ports[0].longitudinal_offset(1), z=0.33 / 2, height=1, eig_band=2)
sim.init_sim()
# plt.imshow(sim.sim.get_epsilon().T)
# plt.show()
# sim.sim.plot3D()
monitors_out = [
sim.add_eigenmode_monitor(mmi.output_ports[i].longitudinal_offset(1), 1.55, 2, 1, z=0.33 / 2, height=1) for i in
range(2)]
sim.plot(mp.Hz)
sim.run(until=150)
# plt.imshow(sim.sim.get_epsilon().T)
# plt.imshow(sim.sim.get_tot_pwr().T, alpha=.5)
# plt.show()
sim.plot(mp.Hz)
phase_difference = np.angle(sim.get_eigenmode_coefficients(monitors_out[0], [2]).alpha[0, 0, 0] /
sim.get_eigenmode_coefficients(monitors_out[1], [2]).alpha[0, 0, 0]) / np.pi
transmissions = [
np.abs(sim.get_eigenmode_coefficients(monitors_out[i], [2]).alpha[0, 0, 0]) ** 2 / source.eig_power(1 / 1.55)
for i in
range(2)]
print('phase difference between outputs: {:.3f}π'.format(phase_difference))
print('transmission to monitor 1: {:.3f}'.format(transmissions[0]))
print('transmission to monitor 2: {:.3f}'.format(transmissions[1]))
def _example_i():
from gdshelpers.parts.splitter import MMI
mmi1 = MMI((0, 0), 0, 1, 42, 7.7, 2, 2)
mmi2 = MMI((0, 10), 0, 1, 42, 7.7, 2, 2)
mmi3 = MMI((0, -10), 0, 1, 42, 7.7, 2, 2)
shapely_objects = []
s3d1 = Shapely3d(mmi1.get_shapely_object(), 0.0, 0.7, (0, 0, 0))
s3d2 = Shapely3d(mmi2.get_shapely_object(), 0.0, 0.7, (0, 255, 0))
s3d3 = Shapely3d(mmi3.get_shapely_object(), 0.0, 0.7, (255, 0, 0))
shapely_objects.append(s3d1)
shapely_objects.append(s3d2)
shapely_objects.append(s3d3)
render_image_and_save_as_blend(shapely_objects, "mmi1")
def _example_ii():
from gdshelpers.parts.splitter import MMI
from gdshelpers.geometry import geometric_union
mmi1 = MMI((0, 0), 0, 1, 42, 7.7, 2, 2)
mmi2 = MMI((0, 10), 0, 1, 42, 7.7, 2, 2)
mmi3 = MMI((0, -10), 0, 1, 42, 7.7, 2, 2)
mmi4 = MMI((0, -20), 0, 1, 42, 7.7, 2, 2)
mmi5 = MMI((0, -30), 0, 1, 42, 7.7, 2, 2)
shapely_objects = []
s3d1 = Shapely3d(
geometric_union([
mmi1.get_shapely_object(),
mmi2.get_shapely_object(),
mmi3.get_shapely_object()
]), 0.0, 0.7, (255, 0, 0))
s3d2 = Shapely3d(
geometric_union([mmi4.get_shapely_object(),
mmi5.get_shapely_object()]), 0.0, 0.7, (0, 255, 0))
shapely_objects.append(s3d1)
shapely_objects.append(s3d2)
render_image_and_save_as_blend(shapely_objects, "mmi2")
def IL_mmi(origin=(0, 0),
len_in=500,
radius=10,
num_roundtrip=3,
len_deltaL=250,
w_etch=3):
"""
total delta L = 4*len_delta_L * num_rountrip
"""
# coupler_params = {
# 'width': 0.45,
# 'full_opening_angle': np.deg2rad(40),
# 'grating_period': 0.64,
# 'grating_ff': 0.546875,
# 'n_gratings': 20,
# 'taper_length': 16,
# }
mmi_params = {
'length': 31.37,
'width': 6,
'taper_width': 2.9,
'taper_length': 20,
}
# gc_start
# gc_start = GratingCoupler.make_traditional_coupler(origin, angle=-np.pi, **coupler_params)
# staright wg
wg_start = Waveguide(origin, angle=0, width=0.5)
wg_start.add_straight_segment(10)
# mmi_in
mmi_in = MMI.make_at_port(wg_start.port,
num_inputs=1,
num_outputs=2,
**mmi_params)
# mmi_in.
# len_in is the length of the input straight wg
# len_out is the length of the out straight wg
#
# len_in = 500
len_out = len_in
# len_deltaL = 400
# radius = 10
gap = 10
# num_roundtrip = 3
# port 1
wg1 = Waveguide.make_at_port(mmi_in.left_branch_port)
wg1.add_straight_segment(len_in)
i = 0
while i < num_roundtrip:
wg1.add_bend(np.pi, radius)
wg1.add_straight_segment(len_deltaL)
wg1.add_bend(-np.pi, radius)
wg1.add_straight_segment(len_deltaL)
i += 1
wg1.add_straight_segment(6 * radius + 3 * gap)
i = 0
while i < num_roundtrip:
wg1.add_straight_segment(len_deltaL)
wg1.add_bend(-np.pi, radius)
wg1.add_straight_segment(len_deltaL)
wg1.add_bend(np.pi, radius)
i += 1
wg1.add_straight_segment(len_out)
# port 2
wg2 = Waveguide.make_at_port(mmi_in.right_branch_port)
wg2.add_straight_segment(len_in + 2 * radius + gap)
i = 0
while i < num_roundtrip:
wg2.add_bend(np.pi, radius)
wg2.add_bend(-np.pi, radius)
i += 1
wg2.add_straight_segment(2 * radius + gap)
i = 0
while i < num_roundtrip:
wg2.add_bend(-np.pi, radius)
wg2.add_bend(np.pi, radius)
i += 1
wg2.add_straight_segment(len_out + 2 * radius + gap)
# mmi_out
mmi_out = MMI.make_at_port(wg1.port,
num_inputs=2,
num_outputs=1,
**mmi_params)
# straight wg
wg_end = Waveguide.make_at_port(mmi_out.right_branch_port)
wg_end.add_straight_segment(10)
# convert to positive resist
layout = positive_resist.convert_to_positive_resist(
[mmi_in, mmi_out, wg1, wg2, wg_end, wg_start],
w_etch,
outer_resolution=1e-3)
gap = 10
outer_corners = [
origin, (origin[0], origin[1] + 2 * gap),
(origin[0] - 2 * gap, origin[1] + 2 * gap),
(origin[0] - 2 * gap, origin[1] - 2 * gap),
(origin[0], origin[1] - 2 * gap)
]
polygon1 = Polygon(outer_corners)
origin = wg_end._current_port.origin
print("End Point： ", origin)
origin[0] = origin[0] + 2 * gap
outer_corners = [
origin, (origin[0], origin[1] + 2 * gap),
(origin[0] - 2 * gap, origin[1] + 2 * gap),
(origin[0] - 2 * gap, origin[1] - 2 * gap),
(origin[0], origin[1] - 2 * gap)
]
polygon2 = Polygon(outer_corners)
polygon = polygon1.union(polygon2)
layout_fixed = layout.difference(polygon)
return layout_fixed