Steady-state and transient Brillouin gain in magnetoactive narrow band gap semiconductors

摘要

Using electromagnetic treatment, a detailed analytical investigation is made to investigate both the steady-state and transient gains of Brillouin Stokes mode in magnetoactive piezoelectric Ⅲ-Ⅴ semiconductors. The Brillouin Stokes mode arises from the nonlinear interaction of an intense pump beam with the internally generated acoustic phonon mode and magnetoacoustic phonon mode in the finiteness of piezoelectricity and electrostriction. Following a coupled-mode approach, the third-order (Brillouin) susceptibility and steady-state and transient regime Brillouin gain of the backward Stokes mode are obtained in the presence and absence of an external static magnetic field. The dependence of the piezoelectricity, an external static magnetic field and pump pulse duration on growth rate of the backward Stokes mode has been analysed. The piezoelectricity and an externally applied static magnetic field substantially enhance both the steady-state and transient gain coefficients in a moderately doped Ⅲ-Ⅴ semiconductor. The enhanced transient gain coefficient can be greatly used in the compression of the backward scattered Stokes pulse.