diff --git a/gwinc/noise/quantum.py b/gwinc/noise/quantum.py
index 73f0112dba09207ed6b864b6800a056c4eeb5563..e974f04884856c4a61b4a1c0141d3fdad5d0eb80 100644
--- a/gwinc/noise/quantum.py
+++ b/gwinc/noise/quantum.py
@@ -5,6 +5,12 @@ import scipy.constants
 import logging
 from ..struct import Struct
 
+def sqzOptimalSqueezeAngle(Mifo, eta):
+    vHD = np.array([[sin(eta), cos(eta)]])
+    H = getProdTF(vHD, Mifo)[0]
+    alpha = arctan(abs(H[1]), abs(H[0]))
+    return alpha
+
 
 def shotrad(f, ifo):
     """Quantum noise