  Generation of quasi-particle--hole pairs in gapped graphene monolayers in the
combined field of two counterpropagating light waves is studied. The process
represents an analogue of electron-positron pair production from the QED vacuum
by the Breit-Wheeler effect. We show, however, that the two-dimensional
structure of graphene causes some striking differences between both scenarios.
In particular, contrary to the QED case, it allows for non-zero pair production
rates at the energy threshold when the Breit-Wheeler reaction proceeds
nonlinearly with absorption of three photons.
