Analysis of the frequency characteristics of the spin-injection emitter in the terahertz range using a diffraction grating

A method for the measurement and identification of the radiation frequencies of the spin-injection oscillator in the terahertz frequency range using a diffraction grating is developed and experimentally implemented. For the system consisting of a ferromagnetic rod (Fe) and nanosized ferromagnetic film (Fe3O4 with a thickness of up to 100 nm), the thermal and dynamic components of the radiation that is induced by the current flow are separated. The diffraction peaks at a frequency of about 9.6 THz and a band of 37% at a level of 3 dB and at a frequency of 43.5 THz are demonstrated. It is shown that the intensity of each signal is significantly higher than the thermal background level.