Die assembly

Die assembly#

With gdsfactory you can easily go from a simple component, to a component with many components inside.

In the same way that you need to Layout for DRC (Design Rule Check) clean devices, you have to layout obeying the Design for Test (DFT) and Design for Packaging rules.

Design for Test#

To measure your chips after fabrication you need to decide your test configurations. This includes Design For Testing Rules like:

  • Individual input and output fibers versus fiber array. You can use add_fiber_array for easier testing and higher throughput, or add_fiber_single for the flexibility of single fibers.

  • Fiber array pitch (127um or 250um) if using a fiber array.

  • Pad pitch for DC and RF high speed probes (100, 125, 150, 200um). Probe configuration (GSG, GS …)

  • Test layout for DC, RF and optical fibers.

from functools import partial

import gdsfactory as gf

# After you run gf.config.rich_output(), gdsfactory will automatically generate and display a plot of the component's geometry instead of the text.
gf.config.rich_output()

Pack#

Let us start with a resistance sweep, where you change the resistance width to measure sheet resistance.

def add_resistance_sweep_info(c):
    # A helper function is defined to add specific metadata to a component's .info attribute.
    # This information, like "doe": "resistance_sweep" (Design of Experiments) and "measurement": "iv" (current-voltage),
    # is used by automated testing and data analysis tools.
    c.info["doe"] = "resistance_sweep"
    c.info["analysis"] = "[iv_resistance]"
    c.info["analysis_parameters"] = "[{}]"
    c.info["ports_electrical"] = 2
    c.info["ports_optical"] = 0
    c.info["measurement"] = "iv"
    c.info["measurement_parameters"] = "{}"
    return c

# A list of three resistance_sheet components is created, each with a different width (1, 10, and 50 µm).
sweep = [gf.components.resistance_sheet(width=width) for width in [1, 10, 50]]

# The add_resistance_sweep_info function is applied to each of the three resistor components, embedding the testing metadata into each one.
sweep_with_info = [add_resistance_sweep_info(c) for c in sweep]

# The gf.pack function takes the list of three components and automatically arranges them in a compact way,
# creating a single, larger component that contains them. m[0] retrieves this final packed component.
m = gf.pack(sweep_with_info)
c = m[0]
c.draw_ports()
c.pprint_ports()
c.plot()

┏━━━━━━━━┳━━━━━━━┳━━━━━━━━━━━━━┳━━━━━━━━━━━┳━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━┓
┃ name   ┃ width ┃ orientation ┃ layer     ┃ center           ┃ port_type  ┃
┡━━━━━━━━╇━━━━━━━╇━━━━━━━━━━━━━╇━━━━━━━━━━━╇━━━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━┩
│ 0_pad1 │ 50.0  │ 270.0       │ M3 (49/0) │ (30.05, 5.05)    │ electrical │
│ 0_pad2 │ 50.0  │ 270.0       │ M3 (49/0) │ (130.05, 5.05)   │ electrical │
│ 1_pad1 │ 50.0  │ 270.0       │ M3 (49/0) │ (30.05, 65.05)   │ electrical │
│ 1_pad2 │ 50.0  │ 270.0       │ M3 (49/0) │ (130.05, 65.05)  │ electrical │
│ 2_pad1 │ 50.0  │ 270.0       │ M3 (49/0) │ (30.05, 125.05)  │ electrical │
│ 2_pad2 │ 50.0  │ 270.0       │ M3 (49/0) │ (130.05, 125.05) │ electrical │
└────────┴───────┴─────────────┴───────────┴──────────────────┴────────────┘



../_images/5f3ce9d938de1b1262795b64f8aa1dd6ee494899180f4522c8ad247da1f21936.png









sweep_with_info[0].info











Info(
    resistance=0,
    length=50.0,
    width=1,
    doe='resistance_sweep',
    analysis='[iv_resistance]',
    analysis_parameters='[{}]',
    ports_electrical=2,
    ports_optical=0,
    measurement='iv',
    measurement_parameters='{}'
)









Then we add spirals with different lengths to measure the waveguide propagation loss. You can use both a fiber array or single fiber.






@gf.cell

# This line creates the basic spiral waveguide. The **kwargs allows you to pass any parameters (like length, width, etc.) to the underlying spiral component.
def spiral_gc(**kwargs):
    """Returns spiral with Grating Couplers."""
    c = gf.components.spiral(**kwargs)
    c = gf.routing.add_fiber_array(c)
    c.info["doe"] = "spirals_sc"  # Strip Cband spirals
    c.info["measurement"] = "optical_spectrum"
    c.info["measurement_parameters"] = "{}"
    c.info["analysis"] = "[power_envelope]"
    c.info["analysis_parameters"] = "[]"
    c.info["ports_optical"] = 4
    c.info["ports_electrical"] = 0
    c.info.update(kwargs)
    return c


c = spiral_gc(length=100)
c.plot()











../_images/2fba64c3e02ecbe88da9f92759698e3376ac6ea741f81b49e51f158f2b75445e.png









c.info











Info(
    length=100,
    doe='spirals_sc',
    measurement='optical_spectrum',
    measurement_parameters='{}',
    analysis='[power_envelope]',
    analysis_parameters='[]',
    ports_optical=4,
    ports_electrical=0
)













sweep = [spiral_gc(length=length) for length in [100, 200, 300]]
m = gf.pack(sweep)
c = m[0]
c.plot()











../_images/7752879da42b3a897804e003dd3869804a59ab6919c06f1802b24cb92e9d278d.png





You can also add some physical labels that will be fabricated.
For example you can add prefix S at the north-center of each spiral using text_rectangular which is DRC clean and anchored on nc (north-center).






text_metal = partial(gf.components.text_rectangular_multi_layer, layers=("M1",))

m = gf.pack(sweep, text=text_metal, text_anchors=("cw",), text_prefix="s")
c = m[0]
c.show()
c.plot()









2025-10-30 04:54:12.016 | WARNING  | kfactory.kcell:show:4022 - Could not connect to klive server







../_images/daae318f5121b31a8276a3a43fdd008111300540bf35a506ffb1e8c757cbb8bc.png









Grid#


You can also pack components with a constant spacing.






g = gf.grid(sweep)
g.plot()











../_images/8be34910327c6e3b136d9e24d9961a7828f3cb7d52b0a0c15ffdf0d865415d26.png









gh = gf.grid(sweep, shape=(1, len(sweep)))
gh.plot()











../_images/36eff9b0f15441b8e0b60c17d32c12a8d55586b571e1553b8600ab2f0294a7bd.png









gh_ymin = gf.grid(sweep, shape=(len(sweep), 1), align_x="xmin")
gh_ymin.plot()











../_images/2d705e6504557f20c40a9c5d18d7f7e1a0f4332f56654b79a45756c5a8efea9b.png





Additionally, it allows you to add text labels to each element of the sweep






gh_ymin = gf.grid_with_text(
    
    # shape=(len(sweep), 1): This defines the grid as having a single column and a number of rows equal to the number of components in the sweep list.
    # align_x="xmax": This aligns all the components in the column so that their right edges (xmax) are in a straight vertical line.
    # text=text_metal: This provides a list of text strings that will be placed as labels next to each corresponding component in the grid.
    sweep, shape=(len(sweep), 1), align_x="xmax", text=text_metal
)
gh_ymin.plot()











../_images/f67c4e5ff1d63a2189a1c25fed2a35f588de0f684e9315891feddd620065b5af.png









gh_ymin = gf.grid_with_text(
    sweep,
    shape=(len(sweep), 1),
    align_x="xmax",
    text=text_metal,
    labels=("S100", "S200", "S300"),
)
gh_ymin.plot()











../_images/eef43bc1deca20156456f0adbdfbda1a786e678d14b4c7e792222c228a0d715e.png





You have 2 ways of defining a mask:


    

  1. in YAML
    2. 

  2. in Python
    3. 







YAML Component#


You can also define your Component in the YAML format thanks to gdsfactory.read.from_yaml


You need to define:


    

  • Instances
    • 

  • Placements
    • 

  • Routes (optional)
    • 



And you can leverage:


    

  1. pack_doe
    2. 

  2. pack_doe_grid
    3. 



pack_doe places components as compact as possible.


pack_doe_grid places each component on a regular grid.






c = gf.read.from_yaml(
    """
name: mask_compact

instances:
  rings:

  #  This is a special function that creates a Design of Experiments array.
    component: pack_doe
    settings:
      
      # settings: radius: [30, 50, 20, 40], length_x: [1, 2, 3]: It will create ring resonators with these different radii and coupling lengths.
      doe: ring_single
      settings:
        radius: [30, 50, 20, 40]
        length_x: [1, 2, 3]

      # This tells the function to generate all possible combinations of the specified radius and length_x values.
      do_permutations: True
      function:

        # After each unique ring is created, the add_fiber_array function is applied to it, adding grating couplers for testing.
        function: add_fiber_array
        settings:
            fanout_length: 200


  mzis:
    component: pack_doe_grid
    settings:
      doe: mzi
      settings:
        delta_length: [10, 100]
      do_permutations: True
      spacing: [10, 10]
      function: add_fiber_array

placements:
  rings:
    xmin: 50

  mzis:
    xmin: rings,east
"""
)

c.show()
c.plot()









2025-10-30 04:54:13.421 | WARNING  | kfactory.kcell:show:4022 - Could not connect to klive server







../_images/06c6fb2f0d73f04145d9453992581687cf5a32c7a3098d7130c02c865e707bc2.png









Automated testing and analysis#


This is useful when you have a lot of components and you want to automate the testing process.


There are two main ways to define which components are testable:


    

  1. Include a doe (Design of Experiments) field in the component.info dictionary, as well as all relevant test and analysis information.
    2. 

  2. Include a GDS label in all component test points. There are many ways to define test points, but the most common is to use a GDS label with the format <elec/opt>-<number_of_ports>-<cell_name>. This way you can easily extract all test points from the GDS file.
    3. 







import pandas as pd

import gdsfactory as gf


@gf.cell
def mzm_gc(length_x=10, **kwargs) -> gf.Component:
    """Returns a MZI with Grating Couplers.

    Args:
        length_x: length of the MZI.
        kwargs: additional settings.
    """
    c = gf.components.mzi2x2_2x2_phase_shifter(
        length_x=length_x, auto_rename_ports=False, **kwargs
    )
    c = gf.routing.add_pads_top(c, port_names=["top_l_e1", "top_r_e3"])
    c = gf.routing.add_fiber_array(c)
    c.info["doe"] = "mzm"
    c.info["measurement"] = "optical_spectrum"
    c.info["analysis"] = "[fsr]"
    c.info["analysis_parameters"] = "[]"
    c.info["ports_electrical"] = 2
    c.info["ports_optical"] = 6
    c.info["length_x"] = length_x
    c.info.update(kwargs)
    return c


def sample_reticle(grid: bool = False) -> gf.Component:
    """Returns MZI with TE grating couplers."""

    mzis = [mzm_gc(length_x=lengths) for lengths in [100, 200, 300]]
    spirals = [spiral_gc(length=length) for length in [0, 100, 200]]
    rings = []
    for length_x in [10, 20, 30]:
        ring = gf.components.ring_single_heater(length_x=length_x)
        c = gf.components.add_fiber_array_optical_south_electrical_north(
            component=ring,
            electrical_port_names=["l_e2", "r_e2"],
            grating_coupler=gf.components.grating_coupler_te, 
            pad=gf.components.pad,
            cross_section_metal='metal3'
        ).copy()
        c.name = f"ring_{length_x}"
        c.info["doe"] = "ring_length_x"
        c.info["measurement"] = "optical_spectrum"
        c.info["ports_electrical"] = 2
        c.info["ports_optical"] = 4
        c.info["analysis"] = "[fsr]"
        c.info["analysis_parameters"] = "[]"
        c.info["length_x"] = length_x
        rings.append(c)

    copies = 3  # Number of copies of each component.
    components = mzis * copies + rings * copies + spirals * copies
    if grid:
        return gf.grid(components)
    mask = gf.pack(components)
    if len(mask) > 1:
        mask = gf.pack(mask)
    return mask[0]


c = sample_reticle()
c.show()
c









2025-10-30 04:54:14.292 | WARNING  | kfactory.kcell:show:4022 - Could not connect to klive server







../_images/7c4142e78b4dac6a9dfd1e687f3e639c4448c530ef087ba6685bf113c6eda237.png









gf.labels.write_test_manifest(c, csvpath="sample_reticle.csv")
df = pd.read_csv("sample_reticle.csv")
df









Warning: 'measurement_parameters' missing from 'mzm_gc_LX100'
Warning: 'measurement_parameters' missing from 'mzm_gc_LX200'
Warning: 'measurement_parameters' missing from 'mzm_gc_LX300'
Warning: 'measurement_parameters' missing from 'mzm_gc_LX100'
Warning: 'measurement_parameters' missing from 'mzm_gc_LX200'
Warning: 'measurement_parameters' missing from 'mzm_gc_LX300'
Warning: 'measurement_parameters' missing from 'mzm_gc_LX100'
Warning: 'measurement_parameters' missing from 'mzm_gc_LX200'
Warning: 'measurement_parameters' missing from 'mzm_gc_LX300'
Warning: 'measurement_parameters' missing from 'ring_10'
Warning: 'measurement_parameters' missing from 'ring_20'
Warning: 'measurement_parameters' missing from 'ring_30'
Warning: 'measurement_parameters' missing from 'ring_10'
Warning: 'measurement_parameters' missing from 'ring_20'
Warning: 'measurement_parameters' missing from 'ring_30'
Warning: 'measurement_parameters' missing from 'ring_10'
Warning: 'measurement_parameters' missing from 'ring_20'
Warning: 'measurement_parameters' missing from 'ring_30'











  
    

      
      cell
      x
      y
      info
      ports
      settings
      doe
      analysis
      analysis_parameters
      measurement
      measurement_parameters
      ports_optical
      ports_electrical
    

  
  
    

      0
      mzm_gc_LX100
      250.020
      153.225
      {"length_x": 100}
      {"in_o1": {"name": "in_o1", "center": [145020,...
      {"length_x":100}
      mzm
      [fsr]
      []
      optical_spectrum
      NaN
      6
      2
    

    

      1
      mzm_gc_LX200
      200.020
      419.775
      {"length_x": 200}
      {"in_o1": {"name": "in_o1", "center": [145020,...
      {"length_x":200}
      mzm
      [fsr]
      []
      optical_spectrum
      NaN
      6
      2
    

    

      2
      mzm_gc_LX300
      150.020
      686.325
      {"length_x": 300}
      {"in_o1": {"name": "in_o1", "center": [145020,...
      {"length_x":300}
      mzm
      [fsr]
      []
      optical_spectrum
      NaN
      6
      2
    

    

      3
      mzm_gc_LX100
      250.020
      952.876
      {"length_x": 100}
      {"in_o1": {"name": "in_o1", "center": [145020,...
      {"length_x":100}
      mzm
      [fsr]
      []
      optical_spectrum
      NaN
      6
      2
    

    

      4
      mzm_gc_LX200
      200.020
      1219.426
      {"length_x": 200}
      {"in_o1": {"name": "in_o1", "center": [145020,...
      {"length_x":200}
      mzm
      [fsr]
      []
      optical_spectrum
      NaN
      6
      2
    

    

      5
      mzm_gc_LX300
      150.020
      1485.976
      {"length_x": 300}
      {"in_o1": {"name": "in_o1", "center": [145020,...
      {"length_x":300}
      mzm
      [fsr]
      []
      optical_spectrum
      NaN
      6
      2
    

    

      6
      mzm_gc_LX100
      250.020
      1752.526
      {"length_x": 100}
      {"in_o1": {"name": "in_o1", "center": [145020,...
      {"length_x":100}
      mzm
      [fsr]
      []
      optical_spectrum
      NaN
      6
      2
    

    

      7
      mzm_gc_LX200
      200.020
      2019.076
      {"length_x": 200}
      {"in_o1": {"name": "in_o1", "center": [145020,...
      {"length_x":200}
      mzm
      [fsr]
      []
      optical_spectrum
      NaN
      6
      2
    

    

      8
      mzm_gc_LX300
      820.960
      153.225
      {"length_x": 300}
      {"in_o1": {"name": "in_o1", "center": [815960,...
      {"length_x":300}
      mzm
      [fsr]
      []
      optical_spectrum
      NaN
      6
      2
    

    

      9
      ring_10
      884.460
      367.151
      {"length_x": 10}
      {"o1": {"name": "o1", "center": [815960, 30066...
      {"component":"ring_double_heater_gdsfactorypco...
      ring_length_x
      [fsr]
      []
      optical_spectrum
      NaN
      4
      2
    

    

      10
      ring_20
      889.460
      727.151
      {"length_x": 20}
      {"o1": {"name": "o1", "center": [815960, 66066...
      {"component":"ring_double_heater_gdsfactorypco...
      ring_length_x
      [fsr]
      []
      optical_spectrum
      NaN
      4
      2
    

    

      11
      ring_30
      894.460
      1087.151
      {"length_x": 30}
      {"o1": {"name": "o1", "center": [815960, 10206...
      {"component":"ring_double_heater_gdsfactorypco...
      ring_length_x
      [fsr]
      []
      optical_spectrum
      NaN
      4
      2
    

    

      12
      ring_10
      884.460
      1447.151
      {"length_x": 10}
      {"o1": {"name": "o1", "center": [815960, 13806...
      {"component":"ring_double_heater_gdsfactorypco...
      ring_length_x
      [fsr]
      []
      optical_spectrum
      NaN
      4
      2
    

    

      13
      ring_20
      889.460
      1807.151
      {"length_x": 20}
      {"o1": {"name": "o1", "center": [815960, 17406...
      {"component":"ring_double_heater_gdsfactorypco...
      ring_length_x
      [fsr]
      []
      optical_spectrum
      NaN
      4
      2
    

    

      14
      ring_30
      1311.400
      367.151
      {"length_x": 30}
      {"o1": {"name": "o1", "center": [1232900, 3006...
      {"component":"ring_double_heater_gdsfactorypco...
      ring_length_x
      [fsr]
      []
      optical_spectrum
      NaN
      4
      2
    

    

      15
      ring_10
      1301.400
      727.151
      {"length_x": 10}
      {"o1": {"name": "o1", "center": [1232900, 6606...
      {"component":"ring_double_heater_gdsfactorypco...
      ring_length_x
      [fsr]
      []
      optical_spectrum
      NaN
      4
      2
    

    

      16
      ring_20
      1306.400
      1087.151
      {"length_x": 20}
      {"o1": {"name": "o1", "center": [1232900, 1020...
      {"component":"ring_double_heater_gdsfactorypco...
      ring_length_x
      [fsr]
      []
      optical_spectrum
      NaN
      4
      2
    

    

      17
      ring_30
      1311.400
      1447.151
      {"length_x": 30}
      {"o1": {"name": "o1", "center": [1232900, 1380...
      {"component":"ring_double_heater_gdsfactorypco...
      ring_length_x
      [fsr]
      []
      optical_spectrum
      NaN
      4
      2
    

    

      18
      spiral_gc_L200
      1395.179
      140.351
      {"length": 200}
      {"o1": {"name": "o1", "center": [1551179, 3411...
      {"length":200}
      spirals_sc
      [power_envelope]
      []
      optical_spectrum
      {}
      4
      0
    

    

      19
      spiral_gc_L200
      1141.179
      1846.901
      {"length": 200}
      {"o1": {"name": "o1", "center": [1297179, 1740...
      {"length":200}
      spirals_sc
      [power_envelope]
      []
      optical_spectrum
      {}
      4
      0
    

    

      20
      spiral_gc_L200
      1141.179
      2030.451
      {"length": 200}
      {"o1": {"name": "o1", "center": [1297179, 1924...
      {"length":200}
      spirals_sc
      [power_envelope]
      []
      optical_spectrum
      {}
      4
      0
    

    

      21
      spiral_gc_L100
      1593.840
      323.901
      {"length": 100}
      {"o1": {"name": "o1", "center": [1649840, 2176...
      {"length":100}
      spirals_sc
      [power_envelope]
      []
      optical_spectrum
      {}
      4
      0
    

    

      22
      spiral_gc_L100
      1593.840
      507.451
      {"length": 100}
      {"o1": {"name": "o1", "center": [1649840, 4012...
      {"length":100}
      spirals_sc
      [power_envelope]
      []
      optical_spectrum
      {}
      4
      0
    

    

      23
      spiral_gc_L100
      1593.840
      691.001
      {"length": 100}
      {"o1": {"name": "o1", "center": [1649840, 5847...
      {"length":100}
      spirals_sc
      [power_envelope]
      []
      optical_spectrum
      {}
      4
      0
    

    

      24
      spiral_gc_L0
      1693.840
      864.301
      {"length": 0}
      {"o1": {"name": "o1", "center": [1649840, 7683...
      {"length":0}
      spirals_sc
      [power_envelope]
      []
      optical_spectrum
      {}
      4
      0
    

    

      25
      spiral_gc_L0
      1693.840
      1037.601
      {"length": 0}
      {"o1": {"name": "o1", "center": [1649840, 9416...
      {"length":0}
      spirals_sc
      [power_envelope]
      []
      optical_spectrum
      {}
      4
      0
    

    

      26
      spiral_gc_L0
      1693.840
      1210.901
      {"length": 0}
      {"o1": {"name": "o1", "center": [1649840, 1114...
      {"length":0}
      spirals_sc
      [power_envelope]
      []
      optical_spectrum
      {}
      4
      0
    

  







You can see a test manifest example here






Automated testing with labels#


The GDS info is stored in the GDS file metadata and can be lost if the GDS file is modified with other tools that are not aware of the metadata. To avoid this, GDSFactory also supports a more traditional way of defining test points, using GDS labels.


For example, lets say you want to label the rightmost port of a component with a GDS label port_type-number_of_ports-cell_name. You can do this with the following code:






import gdsfactory as gf
from gdsfactory.typings import LayerSpec

layer_label = "TEXT"


def label_farthest_right_port(
    component: gf.Component, ports: gf.Port | list[gf.Port], layer: LayerSpec, text: str
) -> gf.Component:
    """Adds a label to the right of the farthest right port in a given component.

    Args:
        component: The component to which the label is added.
        ports: A list of ports to evaluate for positioning the label.
        layer: The layer on which the label will be added.
        text: The text to display in the label.
    """
    rightmost_port = max(ports, key=lambda port: port.dx)

    component.add_label(
        text=text,
        position=rightmost_port.dcenter,
        layer=layer,
    )
    return component


c = gf.Component()
ref = c << gf.routing.add_pads_top(gf.components.wire_straight())

# ref.ports: The function takes the list of all ports from the component reference ref.
# It then iterates through these ports to find the one with the largest x-coordinate (the one that is farthest to the right).
# c.add_label(...): Once the rightmost port is identified, the function adds a text label to the main component c at that port's position.
label_farthest_right_port(c, ref.ports, layer=layer_label, text="elec-2-wire_straight")
c











../_images/6fc7ef076717f6a4c9725ff4c8e7190e2b0c6318d837c5d242b32db9ca90d729.png









def spiral_gc(length: float = 0, **kwargs) -> gf.Component:
    """Returns a spiral double with Grating Couplers.

    Args:
        length: length of the spiral straight section.
        kwargs: additional settings.

    Keyword Args:
        bend: bend component.
        straight: straight component.
        cross_section: cross_section component.
        spacing: spacing between the spiral loops.
        n_loops: number of loops.
    """
    c0 = gf.c.spiral(length=length, **kwargs)
    c = gf.routing.add_fiber_array(c0)
    c.info["doe"] = "spirals_sc"
    c.info["measurement"] = "optical_spectrum"
    c.info["analysis"] = "[power_envelope]"
    c.info["analysis_parameters"] = "[]"
    c.info["ports_optical"] = 4
    c.info["ports_electrical"] = 0
    c.info.update(kwargs)

    c.name = f"spiral_gc_{length}"
    label_farthest_right_port(c, c.ports, layer=layer_label, text=f"opt-4-{c.name}")
    return c


c = spiral_gc(length=0)
c











../_images/6861029b2ba6226a5774080ffeaee35a5065da9f02227dfe3780895f34f09033.png









def mzi_gc(length_x=10, **kwargs) -> gf.Component:
    """Returns a MZI with Grating Couplers.

    Args:
        length_x: length of the MZI.
        kwargs: additional settings.
    """
    c = gf.components.mzi2x2_2x2_phase_shifter(
        length_x=length_x, auto_rename_ports=False, **kwargs
    )
    c = gf.routing.add_pads_top(c, port_names=("top_l_e1", "top_r_e3"))
    c.name = f"mzi_{length_x}"
    c = gf.routing.add_fiber_array(c)

    c.info["doe"] = "mzi"
    c.info["measurement"] = "optical_spectrum"
    c.info["analysis"] = "[fsr]"
    c.info["analysis_parameters"] = "[]"
    c.info["ports_electrical"] = 2
    c.info["ports_optical"] = 6
    c.info["length_x"] = length_x
    c.info.update(kwargs)

    c.name = f"mzi_gc_{length_x}"
    label_farthest_right_port(
        c,
        c.ports.filter(port_type="vertical_te"),
        layer=layer_label,
        text=f"opt-{c.info['ports_optical']}-{c.name}",
    )
    label_farthest_right_port(
        c,
        c.ports.filter(port_type="electrical"),
        layer=layer_label,
        text=f"elec-{c.info['ports_electrical']}-{c.name}",
    )
    return c


c = mzi_gc(length_x=10)
c











../_images/bc66096b61819bf00a384cbf07b614693b6240baf03afc3a9017364b5aa50ae4.png









def sample_reticle_with_labels(grid: bool = False) -> gf.Component:
    """Returns MZI with TE grating couplers."""

    mzis = [mzi_gc(length_x=lengths) for lengths in [100, 200, 300]]
    spirals = [spiral_gc(length=length) for length in [0, 100, 200]]
    rings = []
    for length_x in [10, 20, 30]:
        ring = gf.components.ring_single_heater(length_x=length_x)
        c = gf.components.add_fiber_array_optical_south_electrical_north(
            component=ring,
            electrical_port_names=["l_e2", "r_e2"],
            grating_coupler=gf.components.grating_coupler_te, 
            pad=gf.components.pad,
            cross_section_metal='metal3'
        ).copy()
        c.name = f"ring_{length_x}"
        c.info["doe"] = "ring_length_x"
        c.info["measurement"] = "optical_spectrum"
        c.info["ports_electrical"] = 2
        c.info["ports_optical"] = 4
        c.info["analysis"] = "[fsr]"
        c.info["analysis_parameters"] = "[]"
        label_farthest_right_port(
            c,
            c.ports.filter(port_type="vertical_te"),
            layer=layer_label,
            text=f"opt-{c.info['ports_optical']}-{c.name}",
        )
        label_farthest_right_port(
            c,
            c.ports.filter(port_type="electrical"),
            layer=layer_label,
            text=f"elec-{c.info['ports_electrical']}-{c.name}",
        )
        rings.append(c)

    copies = 3  # Number of copies of each component.
    components = mzis * copies + rings * copies + spirals * copies

    # gf.grid(components): This function is called to arrange the components in a simple, evenly spaced grid.
    if grid:
        return gf.grid(components)
    
    # gf.pack(components): This is the default path. The pack function uses a more advanced algorithm to arrange the components in a space-efficient way,
    # which is important for minimizing the cost of fabrication. This may result in a list of one or more packed groups.
    c = gf.pack(components)
    
    # The pack function can sometimes return multiple packed groups. This code checks if that is the case (len(c) > 1) and, if so,
    # runs pack again on those groups to combine them into one final, single component. The [0] then selects that final component.
    if len(c) > 1:
        c = gf.pack(c)[0]
    return c[0]


c = sample_reticle_with_labels()
c









2025-10-30 04:54:15.062 | ERROR    | kfactory.kcell:name:687 - Name conflict in kfactory.kcell::name at line 687
Renaming Unnamed_325 (cell_index=325) to spiral_gc_0 would cause it to be named the same as:
 - spiral_gc_0 (cell_index=305), function_name=None, basename=None





2025-10-30 04:54:15.102 | ERROR    | kfactory.kcell:name:687 - Name conflict in kfactory.kcell::name at line 687
Renaming add_fiber_array_optical_south_electrical_north_gdsfacto_4ae78d06$1 (cell_index=328) to ring_10 would cause it to be named the same as:
 - ring_10 (cell_index=277), function_name=None, basename=None





2025-10-30 04:54:15.118 | ERROR    | kfactory.kcell:name:687 - Name conflict in kfactory.kcell::name at line 687
Renaming add_fiber_array_optical_south_electrical_north_gdsfacto_a493de3d$1 (cell_index=329) to ring_20 would cause it to be named the same as:
 - ring_20 (cell_index=287), function_name=None, basename=None





2025-10-30 04:54:15.134 | ERROR    | kfactory.kcell:name:687 - Name conflict in kfactory.kcell::name at line 687
Renaming add_fiber_array_optical_south_electrical_north_gdsfacto_56b059a1$1 (cell_index=330) to ring_30 would cause it to be named the same as:
 - ring_30 (cell_index=297), function_name=None, basename=None







../_images/8f47911dd89ac2daf21aabb45f3f29c182b60db153b665f067c48cddbed0c391.png





You can also extract all test points from a GDS file using gf.labels.write_labels






import pandas as pd

gdspath = c.write_gds()
csvpath = gf.labels.write_labels(gdspath, layer_label=layer_label)
df = pd.read_csv(csvpath)
df = df.sort_values(by=["text"])
df









2025-10-30 04:54:15.340 | INFO     | gdsfactory.labels.write_labels:write_labels:92 - Wrote 45 labels to CSV PosixPath('/tmp/gdsfactory/Unnamed_331.csv')











  
    

      
      text
      x
      y
      angle
    

  
  
    

      13
      elec-2-mzi_gc_100
      395.920
      1724.401
      0.0
    

    

      1
      elec-2-mzi_gc_100
      395.920
      125.100
      0.0
    

    

      7
      elec-2-mzi_gc_100
      395.920
      924.751
      0.0
    

    

      3
      elec-2-mzi_gc_200
      445.920
      391.650
      0.0
    

    

      9
      elec-2-mzi_gc_200
      445.920
      1191.301
      0.0
    

    

      15
      elec-2-mzi_gc_200
      445.920
      1990.951
      0.0
    

    

      5
      elec-2-mzi_gc_300
      495.920
      658.200
      0.0
    

    

      17
      elec-2-mzi_gc_300
      1166.860
      125.100
      0.0
    

    

      11
      elec-2-mzi_gc_300
      495.920
      1457.851
      0.0
    

    

      25
      elec-2-ring_10
      929.460
      1601.600
      0.0
    

    

      19
      elec-2-ring_10
      929.460
      521.600
      0.0
    

    

      31
      elec-2-ring_10
      1346.400
      881.600
      0.0
    

    

      21
      elec-2-ring_20
      929.460
      881.600
      0.0
    

    

      27
      elec-2-ring_20
      929.460
      1961.600
      0.0
    

    

      33
      elec-2-ring_20
      1346.400
      1241.600
      0.0
    

    

      29
      elec-2-ring_30
      1346.400
      521.600
      0.0
    

    

      35
      elec-2-ring_30
      1346.400
      1601.600
      0.0
    

    

      23
      elec-2-ring_30
      929.460
      1241.600
      0.0
    

    

      30
      opt-4-ring_10
      1486.900
      660.661
      0.0
    

    

      18
      opt-4-ring_10
      1069.960
      300.661
      0.0
    

    

      24
      opt-4-ring_10
      1069.960
      1380.661
      0.0
    

    

      32
      opt-4-ring_20
      1486.900
      1020.661
      0.0
    

    

      20
      opt-4-ring_20
      1069.960
      660.661
      0.0
    

    

      26
      opt-4-ring_20
      1069.960
      1740.661
      0.0
    

    

      34
      opt-4-ring_30
      1486.900
      1380.661
      0.0
    

    

      28
      opt-4-ring_30
      1486.900
      300.661
      0.0
    

    

      22
      opt-4-ring_30
      1069.960
      1020.661
      0.0
    

    

      42
      opt-4-spiral_gc_0
      1903.840
      768.311
      0.0
    

    

      44
      opt-4-spiral_gc_0
      1903.840
      1114.911
      0.0
    

    

      43
      opt-4-spiral_gc_0
      1903.840
      941.611
      0.0
    

    

      39
      opt-4-spiral_gc_100
      1903.840
      217.661
      0.0
    

    

      40
      opt-4-spiral_gc_100
      1903.840
      401.211
      0.0
    

    

      41
      opt-4-spiral_gc_100
      1903.840
      584.761
      0.0
    

    

      36
      opt-4-spiral_gc_200
      1805.179
      34.111
      0.0
    

    

      37
      opt-4-spiral_gc_200
      1551.179
      1740.661
      0.0
    

    

      38
      opt-4-spiral_gc_200
      1551.179
      1924.211
      0.0
    

    

      12
      opt-6-mzi_gc_100
      653.020
      1633.411
      0.0
    

    

      6
      opt-6-mzi_gc_100
      653.020
      833.761
      0.0
    

    

      0
      opt-6-mzi_gc_100
      653.020
      34.110
      0.0
    

    

      14
      opt-6-mzi_gc_200
      653.020
      1899.961
      0.0
    

    

      8
      opt-6-mzi_gc_200
      653.020
      1100.311
      0.0
    

    

      2
      opt-6-mzi_gc_200
      653.020
      300.660
      0.0
    

    

      16
      opt-6-mzi_gc_300
      1323.960
      34.110
      0.0
    

    

      10
      opt-6-mzi_gc_300
      653.020
      1366.861
      0.0
    

    

      4
      opt-6-mzi_gc_300
      653.020
      567.210
      0.0
    

  











    
    

                

              

              
              
              
              
                
              
            

            
            
              
                



  

  

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