GDSFactory integration

GDSFactory has an interface to meshwell (v1.0.7)

Warning The GDSFactory plugin for meshwell/gmsh has not been updated since meshwell version 1.0.7! Some features may be missing, and some more bugs might be present.

GDSFactory has the concept of a “LayerStack”, which contains the information about the final fabricated layers:

import gmsh
import gdsfactory as gf
from gplugins.gmsh.get_mesh import get_mesh
from gdsfactory.generic_tech.layer_stack import get_layer_stack

PDK = gf.generic_tech.get_generic_pdk()
PDK.bend_points_distance = 0.5

LAYER_STACK = get_layer_stack()
LAYER_STACK.pprint()

c = gf.components.spiral_heater.spiral_racetrack_heater_metal(num=3)
c.plot()

In meshwell 1.0.7, only a ThresholdField as a distance from the surfaces/volumes was supported. From the GDSFactory plugin, this is entered as a dict for the LayerLevels:

resolutions = {}
resolutions["core"] = {"resolution": 0.1, "distance": 5}
resolutions["heater"] = {"resolution": 0.2, "distance": 10}

the “type” argument in get_mesh can be “xy”, “uz”, or “3D”, depending on if a 2D in-plane, 2D out-of-plane cross-section, or 3D mesh si desired:

xbound = (c.dxmin + c.dxmax) / 2
ymax = c.dymin
ymin = (c.dymin + c.dymax) / 2

mesh = get_mesh(
    c,
    type="uz",
    xsection_bounds=[[xbound, ymin], [xbound, ymax]],
    layer_stack=LAYER_STACK,
    filename="heater_uz.msh",
    resolutions=resolutions,
    default_characteristic_length=10,
    wafer_padding=50,
    interface_delimiter="___",
)

try:
    gmsh.initialize()
    gmsh.open("heater_uz.msh")
    gmsh.fltk.run()
except:
    print("Skipping CAD GUI visualization - only available when running locally")

resolutions = {}
resolutions["core"] = {"resolution": 0.5, "distance": 10}
resolutions["heater"] = {"resolution": 5, "distance": 10}

mesh = get_mesh(
    c,
    type="3D",
    layer_stack=LAYER_STACK,
    filename="heater_3D.msh",
    resolutions=resolutions,
    default_characteristic_length=20,
    wafer_padding=50,
    interface_delimiter="___",
)

try:
    gmsh.initialize()
    gmsh.open("heater_3D.msh")
    gmsh.fltk.run()
except:
    print("Skipping CAD GUI visualization - only available when running locally")