Fixed mode rotation for non-colocated field components

CHANGELOG.md

@@ -13,7 +13,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Differentiable `smooth_min`, `smooth_max`, and `least_squares` functions in `tidy3d.plugins.autograd`.
 - Differential operators `grad` and `value_and_grad` in `tidy3d.plugins.autograd` that behave similarly to the autograd operators but support auxiliary data via `aux_data=True` as well as differentiation w.r.t. `DataArray`.
 - `@scalar_objective` decorator in `tidy3d.plugins.autograd` that wraps objective functions to ensure they return a scalar value and performs additional checks to ensure compatibility of objective functions with autograd. Used by default in `tidy3d.plugins.autograd.value_and_grad` as well as `tidy3d.plugins.autograd.grad`.
-
+- `bend_angle_rotation` in `mode_spec` to improve accuracy in some cases when both `bend_radius` and `angle_theta` are defined."
 
 ### Changed
 - `CustomMedium` design regions require far less data when performing inverse design by reducing adjoint field monitor size for dims with one pixel.
@@ -33,7 +33,6 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Users can manually specify the background medium for a structure to be used for geometry gradient calculations by supplying `Structure.background_permittivity`. This is useful when there are overlapping structures or structures embedded in other mediums.
 - Autograd functions can now be called directly on `DataArray` (e.g., `np.sum(data_array)`) in objective functions.
 - Automatic differentiation support for local field projections with `FieldProjectionAngleMonitor` and `FieldProjectionCartesianMonitor` using `FieldProjector.project_fields(far_field_monitor)`.
-- `bend_angle_rotation` in `mode_spec` to improve accuracy when both bend and angle are defined."
 
 ### Changed
 - Improved autograd tracer handling in `DataArray`, resulting in significant speedups for differentiation involving large monitors.

tidy3d/components/mode.py

@@ -131,12 +131,12 @@ class ModeSpec(Tidy3dBaseModel):
         False,
         title="Use fields rotation when both bend and angle are defined",
         description="Defines how modes are computed when both a bend and an angle are defined. "
-        " If `False`, the two coordinate transformations are directly composed. If `True`, the "
-        "structures in the simulation are first rotated, to compute a mode solution at a reference"
-        "plane normal to the bend's azimuthal direction. Then, the fields are rotated to align with"
-        "the mode plane, using the `n_eff` calculated at the reference plane. The second option can"
-        "produce more accurate results, but more care must be taken for example in ensuring that the"
-        "original mode plane intersects the right geometries in the simulation with rotated structures.",
+        "If `False`, the two coordinate transformations are directly composed. "
+        "If `True`, the structures in the simulation are first rotated to compute a mode solution at "
+        "a reference plane normal to the bend's azimuthal direction. Then, the fields are rotated to align with "
+        "the mode plane, using the `n_eff` calculated at the reference plane. The second option can "
+        "produce more accurate results, but more care must be taken, for example, in ensuring that the "
+        "original mode plane intersects the correct geometries in the simulation with rotated structures.",
     )
 
     track_freq: Union[TrackFreq, None] = pd.Field(
@@ -172,17 +172,6 @@ def bend_radius_not_zero(cls, val, values):
             raise SetupError("The magnitude of 'bend_radius' must be larger than 0.")
         return val
 
-    @pd.validator("bend_angle_rotation", always=True)
-    @skip_if_fields_missing(["bend_radius", "bend_axis"])
-    def validate_bend_correction_requirements(cls, val, values):
-        """Ensure that both ``bend_axis`` and ``bend_radius`` are provided if ``bend_correction`` is enabled."""
-        if val is True:
-            if values.get("bend_axis") is None or values.get("bend_radius") is None:
-                raise SetupError(
-                    "'bend_correction' can only be enabled when both 'bend_axis' and 'bend_radius' are provided."
-                )
-        return val
-
     @pd.validator("angle_theta", allow_reuse=True, always=True)
     def glancing_incidence(cls, val):
         """Warn if close to glancing incidence."""