Bhattacharya Aniruddha, Baten Md Zunaid, Iorsh Ivan, Frost Thomas, Kavokin Alexey, Bhattacharya Pallab
Center for Photonics and Multiscale Nanomaterials, Department of Electrical Engineering and Computer Science, University of Michigan, 1301 Beal Avenue, Ann Arbor, Michigan 48109-2122, USA.
National Research University for Information Technology, Mechanics and Optics (ITMO), St. Petersburg 197101, Russia.
Phys Rev Lett. 2017 Aug 11;119(6):067701. doi: 10.1103/PhysRevLett.119.067701. Epub 2017 Aug 10.
A spin-polarized laser offers inherent control of the output circular polarization. We have investigated the output polarization characteristics of a bulk GaN-based microcavity polariton diode laser at room temperature with electrical injection of spin-polarized electrons via a FeCo/MgO spin injector. Polariton laser operation with a spin-polarized current is characterized by a threshold of ∼69 A/cm^{2} in the light-current characteristics, a significant reduction of the electroluminescence linewidth and blueshift of the emission peak. A degree of output circular polarization of ∼25% is recorded under remanent magnetization. A second threshold, due to conventional photon lasing, is observed at an injection of ∼7.2 kA/cm^{2}. The variation of output circular and linear polarization with spin-polarized injection current has been analyzed with the carrier and exciton rate equations and the Gross-Pitaevskii equations for the condensate and there is good agreement between measured and calculated data.
自旋极化激光器可对输出圆偏振进行固有控制。我们通过FeCo/MgO自旋注入器对自旋极化电子进行电注入，研究了基于体GaN的微腔极化激元二极管激光器在室温下的输出偏振特性。自旋极化电流驱动的极化激元激光运行在光电流特性上表现为阈值约为69 A/cm²，电致发光线宽显著减小且发射峰蓝移。在剩余磁化下记录到约25%的输出圆偏振度。在注入电流约为7.2 kA/cm²时观察到由传统光子激光引起的第二个阈值。利用载流子和激子速率方程以及凝聚态的格罗斯 - 皮塔耶夫斯基方程分析了输出圆偏振和线性偏振随自旋极化注入电流的变化，测量数据与计算数据吻合良好。
