  We propose the magnetoplasmon resonance technique to investigate
two-dimensional superconductors (taking MoS$_2$ as an example) in the
fluctuating regime, where the temperature is slightly above the critical
temperature of the superconducting transition. Thus, unpaired electrons and
fluctuating Cooper pairs coexist in the system and interact with each other via
long-range Coulomb forces, forming a Bose-Fermi mixture. We expose the sample
to external time-dependent electromagnetic field with a frequency in
sub-terahertz range and a permanent magnetic field, and show that the
magnetoplasmon response of the system is strongly modified in the presence of
superconducting fluctuations in the vicinity of the superconducting transition.
In particular, the fluctuating Cooper pairs dramatically change the position
and broadening of the magnetoplasmon resonance, which is reflected in the
optical response of the system.
