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gplugins.tidy3d.modes.sweep_n_eff

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gplugins.tidy3d.modes.sweep_n_eff#

gplugins.tidy3d.modes.sweep_n_eff(waveguide: Waveguide, **sweep_kwargs) → ndarray[source]#

Return the effective index for a range of waveguide geometries.

The returned array uses the sweep arguments and the mode index as coordinates to organize the data.

Parameters:

waveguide – base waveguide geometry.

Keyword Arguments:

  • sweep_kwargs – Waveguide arguments and values to sweep.

  • wavelength – wavelength in free space.

  • core_width – waveguide core width.

  • core_thickness – waveguide core thickness (height).

  • core_material – core material. One of: - string: material name. - float: refractive index. - float, float: refractive index real and imaginary part. - function: function of wavelength.

  • clad_material – top cladding material.

  • box_material – bottom cladding material.

  • slab_thickness – thickness of the slab region in a rib waveguide.

  • clad_thickness – thickness of the top cladding.

  • box_thickness – thickness of the bottom cladding.

  • side_margin – domain extension to the side of the waveguide core.

  • sidewall_angle – angle of the core sidewall w.r.t. the substrate normal.

  • sidewall_thickness – thickness of a layer on the sides of the waveguide core to model side-surface losses.

  • sidewall_k – absorption coefficient added to the core material index on the side-surface layer.

  • surface_thickness – thickness of a layer on the top of the waveguide core and slabs to model top-surface losses.

  • surface_k – absorption coefficient added to the core material index on the top-surface layer.

  • bend_radius – radius to simulate circular bend.

  • num_modes – number of modes to compute.

  • group_index_step – if set to True, indicates that the group index must also be calculated. If set to a positive float it defines the fractional frequency step used for the numerical differentiation of the effective index.

  • precision – computation precision.

  • grid_resolution – wavelength resolution of the computation grid.

  • max_grid_scaling – grid scaling factor in cladding regions.

Example

>>> sweep_n_eff(
...     my_waveguide,
...     core_width=[0.40, 0.45, 0.50],
...     core_thickness=[0.22, 0.25],
... )
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