Lumerical INTERCONNECT

The Lumerical INTERCONNECT plugin in gdsfactory can run circuit simulations in INTERCONNECT directly from gdsfactory components.

This is a work-in-progress and can’t handle hierarchical components yet.

This example also requires you to install the UBC PDK, pip install ubcpdk. In addition, access to the Lumerical Python api through lumapi is required. Follow instructions in lumerical_1_fdtd_sparameters.py to this end.

from collections import OrderedDict

import gdsfactory as gf
import matplotlib.pyplot as plt
import numpy as np
import ubcpdk.components as pdk
from gdsfactory.get_netlist import get_instance_name_from_alias as get_instance_name
from gdsfactory.routing import route_single

from gplugins.lumerical.interconnect import plot_wavelength_sweep, run_wavelength_sweep

gf.config.rich_output()

import lumapi

session = lumapi.INTERCONNECT()

Currently, only simulations using CMLs (compact model libraries) are supported, so this tutorial will demonstrate using the SiEPIC EBeam PDK with the ubcpdk package.

circuit = gf.Component("Circuit")

gc1 = circuit << pdk.gc_te1550()
gc2 = circuit << pdk.gc_te1550()
gc3 = circuit << pdk.gc_te1550()

gc1.drotate(180)
gc2.drotate(180)
gc3.drotate(180)

gc2.dmovey(127)
gc3.dmovey(-127)

s = circuit << pdk.y_splitter()
s.dmovex(75)

circuit.show()
circuit

route_in = route_single(gc1.ports["opt1"], s.ports["opt1"])
route_out_top = route_single(s.ports["opt2"], gc2.ports["opt1"])
route_out_bot = route_single(
    s.ports["opt3"], gc3.ports["opt1"], start_straight_length=1000
)

circuit.add(route_in.references)
circuit.add(route_out_top.references)
circuit.add(route_out_bot.references)

circuit.show()

netlist = circuit.get_netlist()

gc1_netlist_instance_name = get_instance_name(circuit, gc1)
gc2_netlist_instance_name = get_instance_name(circuit, gc2)
gc3_netlist_instance_name = get_instance_name(circuit, gc3)

ports_in = {gc1_netlist_instance_name: "opt_fiber"}
ports_out = {
    gc2_netlist_instance_name: "opt_fiber",
    gc3_netlist_instance_name: "opt_fiber",
}

simulation_settings = OrderedDict(
    [
        ("MC_uniformity_thickness", np.array([200, 200])),
        ("MC_uniformity_width", np.array([200, 200])),
        ("MC_non_uniform", 0),
        ("MC_grid", 1e-5),
        ("MC_resolution_x", 200),
        ("MC_resolution_y", 0),
    ]
)

results = run_wavelength_sweep(
    component=circuit,
    session=session,
    ports_in=ports_in,
    ports_out=ports_out,
    simulation_settings=simulation_settings,
    results=("transmission",),
    component_distance_scaling=10,
    setup_mc=True,
)

plot_wavelength_sweep(ports_out=ports_out, results=results, show=True)

MZI Wavelength Sweep

mzi = pdk.mzi()
mzi

# If the ports are in the top-level cell, use a dictionary like this and
# set is_top_level to True in the call to run_wavelength_sweep
ports_in = {"o1": "o1"}
ports_out = {"o2": "o2"}

simulation_settings = OrderedDict(
    [
        ("MC_uniformity_thickness", np.array([200, 200])),
        ("MC_uniformity_width", np.array([200, 200])),
        ("MC_non_uniform", 0),
        ("MC_grid", 1e-5),
        ("MC_resolution_x", 200),
        ("MC_resolution_y", 0),
    ]
)
results = run_wavelength_sweep(
    session=session,
    component=mzi,
    ports_in=ports_in,
    ports_out=ports_out,
    results=("transmission",),
    component_distance_scaling=50,
    simulation_settings=simulation_settings,
    setup_mc=True,
    is_top_level=True,
)

plot_wavelength_sweep(
    ports_out=ports_out, results=results, result_name="'TE' transmission"
)

um = 1e-6
result_name = "'TE' transmission"

for port in ports_out:
    wl = results["transmission"][port]["wavelength"] / um
    T = 10 * np.log10(np.abs(results["transmission"][port][result_name]))
    plt.plot(wl, T, label=str(port))

plt.legend()
plt.xlabel(r"Wavelength ($\mu$m)")
plt.ylabel(f"{result_name} (dB)")
plt.show()