diff --git a/src/scgenerator/physics/pulse.py b/src/scgenerator/physics/pulse.py
index 5d4f2b9..3d558f1 100644
--- a/src/scgenerator/physics/pulse.py
+++ b/src/scgenerator/physics/pulse.py
@@ -237,7 +237,9 @@ def convert_field_units(envelope: np.ndarray, n: np.ndarray, effective_area: flo
 
 
 def c_to_a_factor(effective_area_arr: np.ndarray) -> np.ndarray:
-    return (effective_area_arr / effective_area_arr[0]) ** (1 / 4)
+    return np.where(
+        effective_area_arr != 0, (effective_area_arr / effective_area_arr[0]) ** (1 / 4), 1
+    )
 
 
 def a_to_c_factor(effective_area_arr: np.ndarray) -> np.ndarray: