diff --git a/esbo_etc/classes/optical_component/AHotOpticalComponent.py b/esbo_etc/classes/optical_component/AHotOpticalComponent.py
index 42e1de7..080ef58 100644
--- a/esbo_etc/classes/optical_component/AHotOpticalComponent.py
+++ b/esbo_etc/classes/optical_component/AHotOpticalComponent.py
@@ -3,7 +3,8 @@ from esbo_etc.classes.ITransmissive import ITransmissive
 from esbo_etc.classes.SpectralQty import SpectralQty
 from abc import abstractmethod
 import astropy.units as u
-from astropy.modeling.models import BlackBody
+from esbo_etc.lib.helpers import gb_factory
+from typing import Union, Callable
 
 
 class AHotOpticalComponent(AOpticalComponent):
@@ -12,7 +13,7 @@ class AHotOpticalComponent(AOpticalComponent):
     """
     @abstractmethod
     @u.quantity_input(wl_bins='length', temp=[u.Kelvin, u.Celsius])
-    def __init__(self, parent: ITransmissive, emissivity: SpectralQty, wl_bins: u.Quantity, temp: u.Quantity):
+    def __init__(self, parent: ITransmissive, emissivity: SpectralQty, temp: u.Quantity):
         """
         Initialize a new optical component with thermal emission
 
@@ -22,8 +23,6 @@ class AHotOpticalComponent(AOpticalComponent):
             The parent element of the optical component from which the electromagnetic radiation is received.
         emissivity : SpectralQty
             The spectral emissivity coefficient for the optical surface.
-        wl_bins : Quantity
-            Wavelengths used for binning
         temp: Quantity in Kelvin / Celsius
             Temperature of the optical component
         """
@@ -31,18 +30,22 @@ class AHotOpticalComponent(AOpticalComponent):
         super().__init__(parent)
         if temp > 0 * u.K:
             # Create noise from black body model
-            bb = BlackBody(temperature=temp, scale=1. * u.W / (u.m ** 2 * u.nm * u.sr))
-            self._noise = SpectralQty(wl_bins, bb(wl_bins)) * emissivity
+            if isinstance(emissivity, SpectralQty):
+                bb = gb_factory(temp)
+                self._noise = SpectralQty(emissivity.wl, bb(emissivity.wl)) * emissivity
+            else:
+                bb = gb_factory(temp, emissivity)
+                self._noise = bb
         else:
             self._noise = 0
 
-    def ownNoise(self) -> SpectralQty:
+    def ownNoise(self) -> Union[SpectralQty, Callable, int, float]:
         """
         Calculate the noise created by the optical component
 
         Returns
         -------
-        noise : SpectralQty
+        noise : Union[SpectralQty, Callable, int, float]
             The noise created by the optical component
         """
         return self._noise