Effect of Phase Angle between the External and Internal Electric Field on Amplification and Absorption of Light

Abstract

In this research the relation of amplification and absorption with the phase between external and internal field is found by two approaches. In the first one the electron equation of motion is utilized and the secondbased on the relation between the electric field and the current density the results obtained. Where amplification takes place when the external and internal fields are in phase, while absorption exists when the tow field apposes each other and the amplitude of internal field wave is larger than that of the external field.