Parametric Instabilities of both Space Charge and Electromagnetic Waves in GaAs Semiconductors

摘要

This paper with the non-linear parametric effects on both space waves (with phase velocity equal to the electron drift velocity) and electromagnetic waves (with phase velocity equal to c / (epsilaon)~(1/2), where epsilon is the permittivity) in GaAs semiconductors. If an external electric field is applied, a negative differential conductivity is obtained. Under these conditions, the electron velocity is a function of the electric field, which is given by E=E_0 + E, where E_0 is the constant part and E is the variable part. The analysis of the parametric interaction fo the waves in the GaAs semiconductor is realized considering both the Maxwell's equations and the velocity function. The one-dimensional model and the axis z, as the spreading wave direction, are chosen. The analyses of instabilities are realized -by using the Blombergen's Method. The instability efficiency is determined by the velocity, V_0, the differnetial mobility, mu_D; and the non-linear parameter, V_D; by means of the temperature model of the Gunn Effect. The efficiency is good if the interaction parameter, V_D; by means of the temperature model of the Gunn Effect. The efficiency is good if the interaction parameters As and alpha_S, which are obtained from the system formed by the Maxwell's equations and the velocity function, are optimal. At the critical field value, E_(crit), the mobility changes its sign and becomes negative, as a result, there are obtained non-linear and linear parametric instabilities of the interactions at fields E>=E_(crit). The nonlinear parameter V_d obtains a maximum at the optimal value of electric field, E_(opt), where all linear processes are very effective.