diff --git a/src/scgenerator/__init__.py b/src/scgenerator/__init__.py
index 5de327a..c575341 100644
--- a/src/scgenerator/__init__.py
+++ b/src/scgenerator/__init__.py
@@ -1,7 +1,8 @@
 # flake8: noqa
 from . import math
+from .evaluator import Evaluator
 from .legacy import convert_sim_folder
-from .math import abs2, argclosest, span
+from .math import abs2, argclosest, normalized, span
 from .parameter import Configuration, Parameters
 from .physics import fiber, materials, pulse, simulate, units
 from .physics.simulate import RK4IP, parallel_RK4IP, run_simulation
@@ -19,4 +20,3 @@ from .plotting import (
 from .spectra import SimulationSeries, Spectrum
 from .utils import Paths, _open_config, open_single_config
 from .variationer import DescriptorDict, VariationDescriptor, Variationer, VariationSpecsError
-from .evaluator import Evaluator
diff --git a/src/scgenerator/math.py b/src/scgenerator/math.py
index 2fd8ebc..45aaff0 100644
--- a/src/scgenerator/math.py
+++ b/src/scgenerator/math.py
@@ -77,6 +77,11 @@ def abs2(z: np.ndarray) -> np.ndarray:
     return z.real ** 2 + z.imag ** 2
 
 
+def normalized(z: np.ndarray) -> np.ndarray:
+    ab = abs2(z)
+    return ab / ab.max()
+
+
 def sigmoid(x):
     return 1 / (np.exp(-x) + 1)
 
diff --git a/src/scgenerator/physics/pulse.py b/src/scgenerator/physics/pulse.py
index 77a609f..86b0a8c 100644
--- a/src/scgenerator/physics/pulse.py
+++ b/src/scgenerator/physics/pulse.py
@@ -1151,3 +1151,7 @@ def remove_2nd_order_dispersion2(
     opti = minimize_scalar(score, bounds=(-max_gdd * 1e30, max_gdd * 1e30))
     opti["x"] *= 1e-30
     return propagate(opti.x * 1e30), opti
+
+
+def gdd(w: np.ndarray, gdd: float) -> np.ndarray:
+    return np.exp(0.5j * w ** 2 * gdd)
diff --git a/src/scgenerator/plotting.py b/src/scgenerator/plotting.py
index 4b1822b..16e9ace 100644
--- a/src/scgenerator/plotting.py
+++ b/src/scgenerator/plotting.py
@@ -1041,12 +1041,20 @@ def measure_and_annotate_fwhm(
         field = abs2(field)
     _, (left, right), *_ = pulse.find_lobe_limits(unit.inv(t), field)
     arrow_label = f"{right - left:.1f} {unit.name}"
+
+    annotate_fwhm(ax, left, right, arrow_label, field.max(), side, arrow_length_pts, arrow_props)
+    return right - left
+
+
+def annotate_fwhm(
+    ax, left, right, arrow_label, v_max=1, side="right", arrow_length_pts=20.0, arrow_props=None
+):
     arrow_dict = dict(arrowstyle="->")
     if arrow_props is not None:
         arrow_dict |= arrow_props
     ax.annotate(
         "" if side == "right" else arrow_label,
-        (left, field.max() / 2),
+        (left, v_max / 2),
         xytext=(-arrow_length_pts, 0),
         ha="right",
         va="center",
@@ -1055,13 +1063,12 @@ def measure_and_annotate_fwhm(
     )
     ax.annotate(
         "" if side == "left" else arrow_label,
-        (right, field.max() / 2),
+        (right, v_max / 2),
         xytext=(arrow_length_pts, 0),
         textcoords="offset points",
         arrowprops=arrow_dict,
         va="center",
     )
-    return right - left
 
 
 def partial_plot(root: os.PathLike):