diff --git a/opengate/engines.py b/opengate/engines.py
index 41b2970c4..ef6e02ff2 100644
--- a/opengate/engines.py
+++ b/opengate/engines.py
@@ -5,6 +5,7 @@
 import weakref
 from box import Box
 from anytree import PreOrderIter
+import numpy as np
 
 import opengate_core as g4
 from .exception import fatal, warning, GateImplementationError
@@ -415,6 +416,35 @@ def initialize_optical_material_properties(self):
             for (
                 vol
             ) in self.simulation_engine.simulation.volume_manager.volumes.values():
+                if hasattr(vol, "voxel_materials"):
+                    # True if voxelized volume (ImageVolume)
+                    materials = [m[2] for m in vol.voxel_materials]
+                    materials.append(vol.material)
+                    print(materials)
+                    for i in materials:
+                        # Read all materials contained in voxel_materials
+                        for mat in g4.G4Material.GetMaterialTable:
+                            # Loop on all materials created in the simulation
+                            if str(mat.GetName()) == i:
+                                # If material is in voxel_materials
+                                mat_prop = load_optical_properties_from_xml(
+                                    self.physics_manager.optical_properties_file,
+                                    mat.GetName(),
+                                )
+                                if mat_prop is not None:
+                                    self.g4_optical_material_tables[
+                                        str(mat.GetName())
+                                    ] = create_g4_optical_properties_table(mat_prop)
+                                    mat.SetMaterialPropertiesTable(
+                                        self.g4_optical_material_tables[
+                                            str(mat.GetName())
+                                        ]
+                                    )
+                                else:
+                                    self.simulation_engine.simulation.warn_user(
+                                        f"Could not load the optical material properties for material {mat.GetName()} "
+                                        f"found in volume {vol.name} from file {self.physics_manager.optical_properties_file}."
+                                    )
                 material_name = vol.g4_material.GetName()
                 material_properties = load_optical_properties_from_xml(
                     self.physics_manager.optical_properties_file, material_name
diff --git a/opengate/tests/data b/opengate/tests/data
index 0200198b2..be81811c9 160000
--- a/opengate/tests/data
+++ b/opengate/tests/data
@@ -1 +1 @@
-Subproject commit 0200198b2022f89cff342493a09dff73e5669d6b
+Subproject commit be81811c9514bfcbff5014987b587f96ca6774e1
diff --git a/opengate/tests/src/test092_optic_material.py b/opengate/tests/src/test092_optic_material.py
new file mode 100755
index 000000000..c4679ee0c
--- /dev/null
+++ b/opengate/tests/src/test092_optic_material.py
@@ -0,0 +1,99 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+"""
+Created on Wed Apr  2 09:48:30 2025
+
+@author: fava
+"""
+import opengate as gate
+from opengate.utility import g4_units
+import opengate.tests.utility as utility
+import opengate_core as g4
+import uproot
+import numpy as np
+from scipy.spatial.transform import Rotation
+import itk
+
+
+if __name__ == "__main__":
+
+    paths = utility.get_default_test_paths(__file__, output_folder="test092")
+
+    # Define the Simulation object
+    sim = gate.Simulation()
+
+    # Add a material database
+    sim.volume_manager.add_material_database(paths.data / "GateMaterials.db")
+    sim.physics_manager.special_physics_constructors.G4OpticalPhysics = True
+    paths.test_data = paths.data / "test092"
+    sim.physics_manager.optical_properties_file = paths.test_data / "Materials.xml"
+
+    # Define the units used in the simulation set-up
+    m = gate.g4_units.m
+    cm = gate.g4_units.cm
+    keV = gate.g4_units.keV
+    eV = gate.g4_units.eV
+    Bq = gate.g4_units.Bq
+    mm = gate.g4_units.mm
+    sec = gate.g4_units.second
+    gcm3 = gate.g4_units.g_cm3
+    deg = g4_units.deg
+
+    sim.visu = False
+    sim.visu_type = "qt"
+    sim.number_of_threads = 1
+    sim.random_seed = 123456789
+
+    world = sim.world
+    world.size = [3 * m, 3 * m, 3 * m]
+    world.material = "Air"
+    # world.material = "G4_Galactic"
+    # world.material = "G4_AIR"
+
+    img = itk.imread(paths.test_data / "vox_volume.mhd")
+    spacing = img.GetSpacing()
+    size = np.array(img.GetLargestPossibleRegion().GetSize())
+    center = size * spacing / 2
+
+    patient = sim.add_volume("Image", name="patient")
+    patient.image = paths.test_data / "vox_volume.mhd"  # CT image
+    # patient.material = "Air"
+    patient.material = "G4_AIR"
+    patient.dump_label_image = paths.test_data / "labels_vox_volume.mhd"
+    patient.translation = [0, 0, 0]
+    patient.voxel_materials = [[-2, 2, "Muscle"]]
+    # patient.voxel_materials = [[-500, -49, "Fat"],[-49, 150, "Muscle"]]
+
+    #####################################################################
+
+    # dose = sim.add_actor("DoseActor", "dose")
+    # dose.output_filename = paths.output / "imageVolume_photon_unique.mhd"
+    # dose.attached_to = patient.name
+    # dose.size = size
+    # dose.spacing = spacing
+    # dose.translation = [0, 0, 0]
+    # dose.edep_uncertainty.active = False
+    # dose.hit_type = "random"
+
+    ################################################ Optical photon source
+    source = sim.add_source("GenericSource", "mysource")
+    source.particle = "opticalphoton"
+    source.energy.type = "mono"
+    source.energy.mono = 1.913 * eV
+    # source.position.type = "box"  # plane source
+    source.position.type = "point"
+    # source.position.size = [5.5 * cm, 2.6 * cm, 0]
+    source.direction.type = "momentum"
+    source.direction.momentum = [0, 0, 1]
+    source.position.translation = [
+        0,
+        0,
+        -center[2] * mm,
+    ]  # The source is at the border between the image and the exterior
+    source.n = 100000 / sim.number_of_threads
+
+    stats = sim.add_actor("SimulationStatisticsActor", "Stats")
+    stats.track_types_flag = True
+
+    sim.run()
+    print(stats)