Plasmon-Longitudinal Optical Phonon Interaction Based Modulational Amplification in Weakly Polar Magnetoactive N-Type Doped III-V Semiconductors

摘要

Using the hydrodynamical model of semiconductor plasmas and considering the origin of plasmon-longitudinal optical phonon interaction in effective third-order optical susceptibility, an analytical investigation of modulational amplification is performed in magnetoactive n-type doped III–V semiconductors. Expressions for necessary threshold pump amplitude for the onset of modulational amplification and growth rate of modulated wave have been obtained. Numerical estimations have been made for n-InSb crystal at 77 K illuminated by a 10.6 ?m CO2 laser. The dependence of threshold pump amplitude and growth rate of modulated wave on wave number, externally applied magnetic field (via electron-cyclotron frequency) and doping concentration (via electron-plasma frequency) have been explored. It has been found that the threshold pump amplitude can be lowered whereas the growth rate of modulated wave can be enhanced by proper selection of externally applied magnetic field and doping concentration of semiconductor crystal. The results of the present analytical investigation strongly manifest the importance of magnetoactive heavily n-type doped III–V semiconductors as appropriate hosts for modulational instability processes.