  In framework of classical consideration of electron trajectories in crossed
electric and magnetic fields and conductivity of electron system on cyclotron
resonance in single layer graphene possibility to achieve cyclotron lasing in
hexagonal boron nitride single layer graphene sandwiches is discussed. By
simplified consideration with known data on scattering rate in the sandwiches
it is demonstrated that the continuing wave laser action can be achieved in
high quality sandwiches at room temperature at frequencies above one tera hertz
in magnetic field above one Tesla.
