Step 4: Drawing of common shapes and layout design by Boolean operations

This case shows the drawing of common graphics and the layout design of complex structures by Boolean operations.

The main contents of this section include:

• Commonly_used_shape

• Boolean_operation

• Examples

First, the drawing of some commonly used shapes:

• Rectangle

• Circle

• Polygon

• Ring

• Regular_Polygon

Boolean operations are an important design tool for layout design, especially for complex structures. Common inter-graph Boolean operations mainly include:

• OR

• AND

• NOT

• XOR

Commonly_used_shape

Rectangle

rect = fp.el.Rect(width=10, height=5, center=(0,0), layer=TECH.LAYER.M1_DRW)

Circle

circ = fp.el.Circle(radius=10, initial_degrees=0, final_degrees=120, layer=TECH.LAYER.M1_DRW)

Polygon

poly = fp.el.Polygon(raw_shape=[(-5, 0), (-5, 10), (5, 15), (15, -10)], layer=TECH.LAYER.M1_DRW)

Ring

ring = fp.el.Ring(inner_radius=5, outer_radius=10, layer=TECH.LAYER.M1_DRW)

Regular_Polygon

rpoly = fp.el.RegularPolygon(sides=6, side_length=5, layer=TECH.LAYER.M1_DRW)

The above examples are shown below：

Boolean_operation

OR

bool = rect | circ

AND

bool = rect & circ

NOT

bool = rect - circ

XOR

bool = rect ^ circ

The above examples are shown below：

Full script:

from typing import Tuple

from fnpcell import all as fp
from gpdk.technology import get_technology


class Boolean(fp.IWaveguideLike, fp.PCell):
    def build(self) -> Tuple[fp.InstanceSet, fp.ElementSet, fp.PortSet]:
        insts, elems, ports = super().build()
        TECH = get_technology()

        rect = fp.el.Rect(width=10, height=5, center=(0,0), layer=TECH.LAYER.M1_DRW)
        elems += rect.translated(0, 0)
        circ = fp.el.Circle(radius=8, initial_degrees=0, final_degrees=180, layer=TECH.LAYER.M1_DRW)
        elems += circ.translated(0, 0)
        bool = rect - circ
        elems += bool.translated(20, 0)
        bool = rect & circ
        elems += bool.translated(-20, 0)
        bool = rect | circ
        elems += bool.translated(0, 20)
        bool = rect ^ circ
        elems += bool.translated(0, -20)

        return insts, elems, ports

if __name__ == "__main__":
    from pathlib import Path

    gds_file = Path(__file__).parent / "local" / Path(__file__).with_suffix(".gds").name
    library = fp.Library()

    TECH = get_technology()
    # =============================================================
    # fmt: off

    library += Boolean()

    # fmt: on
    # =============================================================
    fp.export_gds(library, file=gds_file)
    fp.plot(library)

Examples

Import step 3 (Step 1: Build basic building blocks) U-shaped target length MZI structure and plot:

class CircuitBool(fp.IWaveguideLike, fp.PCell):
    def build(self) -> Tuple[fp.InstanceSet, fp.ElementSet, fp.PortSet]:
        insts, elems, ports = super().build()
        TECH = get_technology()

        device = MZI()
        ports += device.ports
        insts += device
        cor = device.polygon_set(layer=TECH.LAYER.FWG_COR)
        # elems += cor
        cld = device.polygon_set(layer=TECH.LAYER.FWG_CLD)
        tre = fp.el.PolygonSet.boolean_sub(cld, cor, layer=TECH.LAYER.FWG_TRE)
        elems += tre.translated(0, -500)

        return insts, elems, ports

The above code implements two types of MZI circuits by Boolean operations, one containing all layer information and one for etched layer trenching, as shown in the figure:

Layout with all layer information：

Partial display is as follows：

Etched layer trenching type circuit partial display：