Trouble understanding normalized variable t: [0,1] for nd.strt()

[lumico]

Hi,

I am trying to create a structure with a straight waveguide on top and a waveguide that tapers upwards on the bottom. I am unsure how to use t correctly, as when I increase the length of the structure, the lower waveguide tapers more and more, which it should not. If it was normalized (i.e. t : [0,1]), I believe my structure should have the same form regardless of length. Can someone help me understand the t variable?

See my code below, thanks!

import math
import nazca as nd
nd.clear_layout()
nd.clear_layers()
nd.clear_xsections()

# add layers to xsection (automatically add the xsection)
nd.add_layer2xsection(xsection='xs1', layer=709, accuracy=0.001)

length_1 = 50
length_2 = 50
rail1_straight = nd.strt(length=length_1, width=0.48, xs="xs1").put(0,0.22+0.48)
rail2_taper = nd.strt(
    width=0,
    length=length_1, 
    edge2=lambda t: 0, 
    edge1=lambda t: 0.12 + 0.2*math.log10(0.87*t*length_1+1), 
    edgepoints=50, xs="xs1"
).put(0,0)

nd.export_gds(filename="strip_to_slot_converter")

[Ronald]

Dear lumico,

It seems the edge definition you used for the taper scales with t*length_1.
Remove length_1 to make it indepent of the length as you need?

Ronald

[lumico]

Ronald,

I realized that very shortly after creating this post and tried to delete but could not. Maybe allow a feature to delete posts to save yourself time? Haha, regardless thank you a bunch for the quick response!

[Author]

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