Nonlinear multimode interaction in a higher-order-mode cyclotron autoresonance maser

A sub-terahertz (0.35 THz) CARM operating in a higher-order mode TE_5,1 is simulated, where nonlinear interaction of the operating mode with its neighboring modes TE_5,2, TM_5,1, and TM_5,2 are taken into account. Results show that the expected operating mode TE_5,1 with ultrahigh gain of 79 dB may be absolutely dominant, although all the neighboring modes grow simultaneously in the multimode-beam interaction process.