diff --git a/meanas/fdfd/waveguide_2d.py b/meanas/fdfd/waveguide_2d.py
index e8f766b..7d1f651 100644
--- a/meanas/fdfd/waveguide_2d.py
+++ b/meanas/fdfd/waveguide_2d.py
@@ -413,7 +413,6 @@ def _normalized_fields(
     shape = [s.size for s in dxes[0]]
 
     # Find time-averaged Sz and normalize to it
-    # H phase is adjusted by a half-cell forward shift for Yee cell, and 1-cell reverse shift for Poynting
     Sz_tavg = inner_product(e, h, dxes=dxes, prop_phase=prop_phase, conj_h=True).real
     assert Sz_tavg > 0, f'Found a mode propagating in the wrong direction! {Sz_tavg=}'
 
diff --git a/meanas/fdfd/waveguide_3d.py b/meanas/fdfd/waveguide_3d.py
index da50533..5048dea 100644
--- a/meanas/fdfd/waveguide_3d.py
+++ b/meanas/fdfd/waveguide_3d.py
@@ -45,6 +45,7 @@ def solve_mode(
             'E': NDArray[complexfloating],
             'H': NDArray[complexfloating],
             'wavenumber': complex,
+            'wavenumber_2d': complex,
         }
         ```
     """
@@ -196,6 +197,8 @@ def compute_overlap_e(
     Etgt = numpy.zeros_like(Ee)
     Etgt[slices2] = Ee[slices2]
 
+    # note no sqrt() when normalizing below since we want to get 1.0 after overlapping with the
+    # original field, not the normalized one
     Etgt /= (Etgt.conj() * Etgt).sum()    # type: ignore
     return cfdfield_t(Etgt)