Undulator-Like Radiation and Cooperative Phenomenon in Semiconductor Microstructure with Grating

In the article the cooperative $N^2$-effect is considered, that is the radiation whose power is ım $N^2$, where N is the number of emitters which in this case is equal to the number of electrons in a bunch. The suggested effect is the result of combining two other effects, Gunn-effect in GaAs and undulator-like radiation which can be produced by means of microstructure with grating (microundulator). It is very probable that the effect can be used for the developing of a new semiconductor-based room temperature source of the THz radiation.