  Magnetic/non-magnetic/heterostructured ultra-thin films' characterisation is
highly demanding due to the emerging diverse applications of such films.
Diverse measurements are usually performed on such systems to infer their
electrical, optical and magnetic properties. We demonstrate that MOKE-based
spin-Hall effect of light (SHEL) is a versatile surface characterization tool
for studying materials' magnetic and dielectric ordering. Using this technique,
we measure magnetic field dependent complex Kerr angle and the coercivity in
ultra-thin films of permalloy (Py) and at molybdenum disulphide (MoS$_2$) -
permalloy (MSPy) hetero-structure interfaces. The measurements are compared
with standard magneto-optic Kerr effect (MOKE) studies to demonstrate that
SHEL-MOKE is a practical alternative to the conventional MOKE method, with
competitive sensitivity. A comprehensive theoretical model and simulation data
are provided to further strengthen the potential of this simple non-invasive
optical method. The theoretical model is applied to extract the optical
conductivity and susceptibility of non-magnetic ultra-thin layers such as
MoS$_2$ .
