Using Secondary Resonances for Amplification of Short-Wave Radiation

It is shown that there exist conditions with which the energy of low-frequency perturbation transforms to energy of high-frequency waves. These conditions we shall name as secondary resonances. It is shown that using of these resonances allows to amplify optical and X-ray radiations in periodic-heterogeneous medium (photonic crystals, perfect natural crystals). Amplification of optical and high-frequency radiation is possible also in gyrotropic medium if conditions for existence of Faraday´s effect fulfils. The energy for the amplification in all cases is delivered by the external perturbation with significantly lower frequency