diff --git a/docs/source/notebooks/00_geometry.py b/docs/source/notebooks/00_geometry.py
index 19aa0538..83faf9ac 100644
--- a/docs/source/notebooks/00_geometry.py
+++ b/docs/source/notebooks/00_geometry.py
@@ -50,7 +50,6 @@
 
 # %%
 c.shapes(c.kcl.layer(1, 0)).insert(poly1)
-# show it in matplotlib and KLayout (you need to have KLayout open and install gdsfactory from the git repo with make install)
 
 # %%
 c.show()  # show in klayout
@@ -59,26 +58,25 @@
 # %% [markdown]
 # **Exercise** :
 #
-# Make a cell similar to the one above that has a second polygon in layer (1, 1)
+# Make a cell similar to the one above that has a second polygon in layer (2, 0)
+#
+# **Solution** :
 
 # %%
 c = kf.KCell()
 points = np.array([(-8, -6), (6, 8), (7, 17), (9, 5)])
 poly = kf.polygon_from_array(points)
 c.shapes(c.kcl.layer(1, 0)).insert(poly1)
-c.shapes(c.kcl.layer(1, 1)).insert(poly1)
+c.shapes(c.kcl.layer(2, 0)).insert(poly1)
 c
 
-# %%
-import kfactory as kf
-
 # %%
 c = kf.KCell()
-
-# %%
-# Create some new geometry from the functions available in the geometry library
 textgenerator = kf.kdb.TextGenerator.default_generator()
 t = textgenerator.text("Hello!", c.kcl.dbu)
+c.shapes(kf.kcl.layer(1, 0)).insert(t)
+c.show()  # show in klayout
+c.plot()
 
 # %%
 r = kf.kdb.DBox(-2.5, -5, 2.5, 5)
@@ -88,18 +86,21 @@
 # Add instances to the new geometry to c, our blank cell
 
 # %%
-c.shapes(kf.kcl.layer(1, 0)).insert(t)
-c.show()  # show in klayout
-c.plot()
-
-# %% [markdown]
-# Using the << operator (identical to add_ref()), add the same geometry a second time
+c = kf.KCell()
+c.shapes(c.kcl.layer(1, 0)).insert(r)
+c.shapes(c.kcl.layer(2, 0)).insert(r)
+c
 
 # %%
-# Now that the geometry has been added to "c", we can move everything around:
+c = kf.KCell()
+textgenerator = kf.kdb.TextGenerator.default_generator()
 text1 = t.transformed(
     kf.kdb.DTrans(0.0, 10.0).to_itype(c.kcl.dbu)
 )  # DTrans is a transformation in microns with arguments (<rotation in 90° increments>, <mirror boolean>, <x in microns>, <y in microns>)
+# Now that the geometry has been added to "c", we can move everything around:
+
+
+# %%
 ### complex transformation example:ce
 #     magnification(float): magnification, DO NOT USE on cells or instances, only shapes, most foundries will not allow magnifications on actual cell instances or cells
 #     rotation(float): rotation in degrees
@@ -118,7 +119,6 @@
 )  # boxes can be moved like this, other shapes and cellss/refs need to be moved with .transform
 r.move(-5, 0)
 
-
 # %%
 c.shapes(c.kcl.layer(1, 0)).insert(text1)
 c.shapes(c.kcl.layer(2, 0)).insert(text2)
@@ -163,27 +163,16 @@ def straight(length=10, width=1, layer=(1, 0)):
 
 # %%
 c = kf.KCell()
-
-# %%
-wg1 = c << straight(length=6, width=2.5, layer=(1, 0))
-wg2 = c << straight(length=11, width=2.5, layer=(1, 0))
-wg3 = c << straight(length=15, width=2.5, layer=(1, 0))
-
-# %%
-# wg2.transform(kf.kdb.DCplxTrans(1, 10, False, 10, 0))
-# wg3.transform(kf.kdb.DCplxTrans(1, 15, False, 20, 0))
-# wg2.movey(10).rotate(10)
-# wg3.movey(20).rotate(15)
-print(c.name)
-c.show()  # show in klayout
-# c.plot()
+wg1 = c << straight(length=1, width=2.5, layer=(1, 0))
+wg2 = c << straight(length=2, width=2.5, layer=(1, 0))
+wg3 = c << straight(length=3, width=2.5, layer=(1, 0))
+c
 
 # %% [markdown]
 # Now we can align everything together using the ports:
 
 # %% [markdown]
-# Each straight has two ports: 'W0' and 'E0'.  These are arbitrary
-# names defined in our straight() function above
+# Each straight has two ports: 'o1' and 'o2'.  These are arbitrary names defined in our straight() function above
 
 # %%
 # Let's keep wg1 in place on the bottom, and connect the other straights to it.
@@ -191,17 +180,13 @@ def straight(length=10, width=1, layer=(1, 0)):
 wg2.connect("o1", wg1.ports["o2"])
 # Next, on wg3 let's grab the "W0" port and connect it to the "E0" on wg2:
 wg3.connect("o1", wg2.ports["o2"])
-
-# %%
-c.show()  # show in klayout
-# c.plot()
-
+c
 
 # %%
 c.add_port(name="o1", port=wg1.ports["o1"])
 c.add_port(name="o2", port=wg3.ports["o2"])
 c.show()  # show in klayout
-# c.plot()
+c.plot()
 
 # %% [markdown]
 # As you can see the `red` labels are for the cell ports while
@@ -236,7 +221,7 @@ def straight(length=10, width=1, layer=(1, 0)):
 
 # %%
 c.show()  # show in klayout
-# c.plot()
+c.plot()
 
 # %% [markdown]
 # ## Ports
@@ -311,9 +296,7 @@ def straight(length=10, width=1, layer=(1, 0)):
 
 # %%
 c2.shapes(c2.kcl.layer(1, 0)).insert(kf.kdb.Text("First label", mwg1_ref.trans))
-# c2.shapes(c2.kcl.layer(1,0).insert(kf.kdb.Text("First label", position=mwg1_ref.center)
 c2.shapes(c2.kcl.layer(1, 0)).insert(kf.kdb.Text("Second label", mwg2_ref.trans))
-# c2.add_label(text="Second label", position=mwg2_ref.center)
 
 # %%
 # It's very useful for recording information about the devices or layout
@@ -323,9 +306,8 @@ def straight(length=10, width=1, layer=(1, 0)):
         kf.kdb.Trans(c2.bbox().right, c2.bbox().top),
     )
 )
-
-# %%
-c2
+c2.show()
+c2.plot()
 
 # %% [markdown]
 # ## Boolean shapes
@@ -428,15 +410,10 @@ def straight(length=10, width=1, layer=(1, 0)):
 # %% [markdown]
 # ## Write GDS
 #
-# [GDSII](https://en.wikipedia.org/wiki/GDSII) is the Standard format for exchanging CMOS and Photonic circuits.
+# [GDSII](https://en.wikipedia.org/wiki/GDSII) is the Standard format for exchanging CMOS circuits with foundries
 #
 # You can write your Cell to GDS file.
 
 
 # %%
 c.write("demo.gds")
-
-# %% [markdown]
-# You can see the GDS file in Klayout viewer.
-#
-# Sometimes you also want to save the GDS together with metadata (settings, port names, widths, locations ...) in YAML
diff --git a/docs/source/notebooks/01_references.py b/docs/source/notebooks/01_references.py
index 729b9105..d24cc634 100644
--- a/docs/source/notebooks/01_references.py
+++ b/docs/source/notebooks/01_references.py
@@ -189,10 +189,6 @@
 # In GDS, there's a type of structure called a "Instance" which takes a cell and repeats it NxM times on a fixed grid spacing. For convenience, `Cell` includes this functionality with the add_array() function.
 # Note that CellArrays are not compatible with ports (since there is no way to access/modify individual elements in a GDS cellarray)
 #
-# gdsfactory also provides with more flexible arrangement options if desired, see for example `grid()` and `packer()`.
-#
-# As well as `gf.cells.array`
-#
 # Let's make a new Cell and put a big array of our Cell `c` in it:
 
 # %%
@@ -204,59 +200,6 @@
 )  # instance the Cell "c" 3 instances in it with a 3 rows, 6 columns array
 c3
 
-# %% [markdown]
-# CellArrays don't have ports and there is no way to access/modify individual elements in a GDS cellarray.
-#
-# gdsfactory provides you with similar functions in `gf.cells.array` and `gf.cells.array_2d`
-
-# %%
-# c4 = gf.Cell("demo_array")  # Create a new blank Cell
-# aref = c4 << gf.cells.array(cell=c, columns=3, rows=2)
-# c4.add_ports(aref.get_ports_list())
-# c4
-
-
-# %%
-# # gf.cells.array?
-
-# %% [markdown]
-# You can also create an array of instances for periodic structures. Lets create a [Distributed Bragg Reflector](https://picwriter.readthedocs.io/en/latest/cells/dbr.html)
-
-
-# %%
-# @gf.cell
-# def dbr_period(w1=0.5, w2=0.6, l1=0.2, l2=0.4, straight=gf.cells.straight):
-#     """Return one DBR period."""
-#     c = gf.Cell()
-#     r1 = c << straight(length=l1, width=w1)
-#     r2 = c << straight(length=l2, width=w2)
-#     r2.connect(port="o1", destination=r1.ports["o2"])
-#     c.add_port("o1", port=r1.ports["o1"])
-#     c.add_port("o2", port=r2.ports["o2"])
-#     return c
-
-
-# l1 = 0.2
-# l2 = 0.4
-# n = 3
-# period = dbr_period(l1=l1, l2=l2)
-# period
-
-# %%
-# dbr = gf.Cell("DBR")
-# dbr.add_array(period, columns=n, rows=1, spacing=(l1 + l2, 100))
-# dbr
-
-# %% [markdown]
-# Finally we need to add ports to the new cell
-
-# %%
-# p0 = dbr.add_port("o1", port=period.ports["o1"])
-# p1 = dbr.add_port("o2", port=period.ports["o2"])
-
-# p1.center = [(l1 + l2) * n, 0]
-# dbr
-
 # %% [markdown]
 # ## connect instances
 #
@@ -339,3 +282,5 @@
 c = kf.cells.euler.bend_euler(radius=5, width=1, layer=0, angle=90)
 c.draw_ports()
 c
+
+# %%
diff --git a/docs/source/notebooks/04_KCL.py b/docs/source/notebooks/04_KCL.py
index 6bf2087c..e0486408 100644
--- a/docs/source/notebooks/04_KCL.py
+++ b/docs/source/notebooks/04_KCL.py
@@ -1,68 +1,83 @@
 # ---
 # jupyter:
 #   jupytext:
+#     custom_cell_magics: kql
 #     text_representation:
 #       extension: .py
-#       format_name: light
-#       format_version: '1.5'
-#       jupytext_version: 1.15.0
+#       format_name: percent
+#       format_version: '1.3'
+#       jupytext_version: 1.11.2
 #   kernelspec:
 #     display_name: Python 3 (ipykernel)
 #     language: python
 #     name: python3
 # ---
 
+# %% [markdown]
 # # Multi - KCLayout / PDK
 
-# Using multiple KCLayout objects as PDKs or Libraries of KCells and parametric KCell-Functions
+# %% [markdown]
+# You can also use multiple KCLayout objects as PDKs or Libraries of KCells and parametric KCell-Functions
 
+# %% [markdown]
 # ## Use multiple KCLayout objects as PDKs/Libraries
 #
 # KCLayouts can act as PDKs. They can be seamlessly instantiated into each other
 
-# +
+# %%
 import kfactory as kf
 
 kcl_default = kf.kcl
-# -
 
+# %% [markdown]
 # Empty default KCLayout
 
+# %%
 kcl_default.kcells
 
+# %%
 # Create a default straight waveguide in the default KCLayout with dbu==0.001 (1nm grid)
 s_default = kf.cells.straight.straight(
     width=1, length=10, layer=kcl_default.layer(1, 0)
 )
 
+# %%
 # There is now a a KCell in the KCLayout
 kcl_default.kcells
 
+# %%
 # Control the dbu is still 1nm
 kcl_default.dbu
 
+# %%
 # Create a new KCLayout to simulate pdk (could be package with e.g. `from test_pdk import kcl as pdk` or similar)
 kcl2 = kf.KCLayout("TEST_PDK")
 # Set the dbu to 0.005 (5nm)
 kcl2.dbu = 0.005
 kcl2.layout.dbu
 
+# %%
 # Since it's a new KCLayout, it's empty
 kcl2
 
+# %%
 # Create an parametric KCell-Function for straights on the new pdk
 sf2 = kf.cells.dbu.Straight(kcl=kcl2)
 
+# %%
 # The function hasn't been added to the function yes, so it's still empty
 sf2.kcl
 
+# %%
 # Add it to the pdk factories
 kcl2.factories.update({"straight": kf.cells.dbu.Straight(kcl2)})
 
+# %%
 # Make an instance with
 s2 = kcl2.factories["straight"](length=10000, width=200, layer=kcl2.layer(1, 0))
 s2.settings
 
+# %%
 # The default kcl's straight uses 1nm grid and is therefore 1000dbu (1um) high and 10000dbu (10um) wide
 print(f"{s_default.bbox().height()=}")
 print(f"{s_default.dbbox().height()=}")
@@ -74,6 +89,7 @@
 print(f"{s2.bbox().width()=}")
 print(f"{s2.dbbox().width()=}")
 
+# %%
 # The ports of the default kcl also have different dbu dimensions, but are the same in um
 print(f"{s_default.ports=}")
 print(f"{s2.ports=}")
@@ -81,23 +97,27 @@
 print(f"{[port.d for port in s_default.ports]=}")
 print(f"{[port.d for port in s2.ports]=}")
 
+# %%
 # Both can be instantiated into the same KCell
 c = kcl_default.kcell()
 si_d = c << s_default
 si_2 = c << s2
 
+# %%
 si_2.connect("o1", si_d, "o2")
 
+# %%
 c
 
 
+# %%
 class LAYER2(kf.LayerEnum):
     kcl = kf.constant(kcl2)
     WG = (1, 0)
 
 
+# %%
 kcl2.layers = LAYER2
 
+# %%
 kcl2.layers
-
-LAYER2