Intensity equations for birefringent spin lasers
Intensity equations for birefringent spin lasers
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DOI：
10.1103/physrevb.103.045306
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发表时间：
2020-11
影响因子：
3.7
通讯作者：
Gaofeng Xu;J. Cao;Velimir Labinac;I. Žutić
中科院分区：
文献类型：
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作者：
Gaofeng Xu;J. Cao;Velimir Labinac;I. Žutić
半导体自旋激光器与传统激光器的区别在于存在自旋偏振载流子。自旋偏振载流子的角动量向光子的转移为激光器的运行提供了重要的机会。通过注入自旋偏振载流子，产生圆偏振光，发射光的偏振可以比其强度更快地改变一个数量级。自旋激光器的这种超快运行依赖于大的双折射，这通常被认为对自旋激光器和传统激光器是有害的。我们使用强度方程引入了自旋激光器的透明描述，阐明了双折射对激光器强度和偏振调制的影响。与通常通过使用复数来描述双折射对激光动力学的作用不同，我们的方法更简单，因为它依赖于实际量并允许解析解。虽然强度调制与双折射无关，但对于偏振调制来说，双折射的增加会直接增加谐振频率。我们的激光器动态操作结果为自旋相关响应和磁阻之外的自旋电子学应用提供了指导。
Semiconductor spin lasers are distinguished from their conventional counterparts by the presence of spin-polarized carriers. The transfer of angular momentum of the spin-polarized carriers to photons provides important opportunities for the operation of lasers. With the injection of spin-polarized carriers, which lead to the circularly polarized light, the polarization of the emitted light can be changed an order of magnitude faster than its intensity. This ultrafast operation of spin lasers relies on a large birefringence, usually viewed as detrimental in spin and conventional lasers. We introduce a transparent description of spin lasers using intensity equations which elucidate the influence of birefringence on the intensity and polarization modulation of lasers. Unlike commonly describing the role of birefringence on laser dynamics by employing complex quantities, our approach is simpler, because it is relying on real quantities and allowing analytical solutions. While intensity modulation is independent of birefringence, for polarization modulation an increase in birefringence directly increases the resonant frequency. Our results for dynamical operation of lasers provide a guide for their spin-dependent response and spintronic applications beyond magnetoresistance.