FAR-INFRARED OPTICALLY DETECTED CYCLOTRON-RESONANCE IN GAAS LAYER GROWN BY MOLECULAR-BEAM EPITAXY

Optically detected cyclotron and impurity resonances in molecular beam epitaxy (MBE)-grown GaAs are investigated in the far-infrared region in order to study their mechanisms. An increase in electron temperatur e due to the resonant absorption is responsible for the optically dete cted cyclotron resonance, A photothermal effect is a dominant mechanis m for the optically detected impurity resonance of 1s-2p(+) in the cas e of the energy of the 2p(+)state lying below the lowest Landau level.