  Recently, the thulium atom has been cooled down to the temperature of
Bose-Einstein condensation. While the condensate of the thulium atom has a lot
of applications in quantum simulations and other areas of physics, it can also
serve as a unique diagnostic tool for many atomic experiments. In the present
study, the Bose-Einstein condensate of the thulium atom was successfully
utilized to diagnose an optical lattice and detect unwanted reflections in the
experiments with the 1064 nm optical lattice, which will further be used in a
quantum gas microscope experiment.
