In this study, the influence of exciton spins relaxation (ESR) on spatial evolution of amplification without population inversion in a four-level GsAs multiple quantum wells is discussed theoretically. The role of propagation distance on absorption, dispersion and group index of weak probe light in the presence and absence of ESR is then analyzed. It is found that exciton spin relaxation (spin decoherence) which resulted from many-particle interaction in semiconductors have essential roles to adjusting the absorption and dispersion properties of weak probe light. Moreover, it is realized that the propagation distance in the presence of ESR can lead to switching between subluminal and superluminal light propagation. Our study provides a suitable treatment for the next generation of all-optical systems in semiconductor nanostructures.

本研究从理论上讨论激子自旋弛豫 (ESR) 对四能级 GsAs 多量子阱中无粒子数反转的放大空间演化的影响。然后分析了在存在和不存在 ESR 的情况下，传播距离对弱探测光的吸收、色散和群指数的作用。发现由半导体中的多粒子相互作用引起的激子自旋弛豫（自旋退相干）对于调节弱探测光的吸收和色散特性具有重要作用。此外，人们认识到，存在 ESR 时的传播距离会导致亚光速和超光速光传播之间的切换。我们的研究为下一代半导体纳米结构中的全光学系统提供了合适的处理方法。