论文标题
石墨烯涂层缸中辐射和非辐射传播等离子模式的Terahertz激光条件
Terahertz lasing conditions of radiative and nonradiative propagating plasmon modes in graphene-coated cylinders
论文作者
论文摘要
越来越多的兴趣填补微型Terahertz/中红外辐射源的空白，尤其是将这些源纳入微/纳米光电电路中。通过使用严格的电磁方法，我们研究了用涂有石墨烯层的活性材料制成的圆柱体中辐射和非辐射传播表面平价模式的激发条件和电气可控性。对不同表面平板模式的激光条件的详细分析表明，当模式变得非生育时，所需的增益突然发生了变化。尽管受辐射损失和欧姆损失的辐射模式预计需要比非放射性模式更多的增益补偿，但我们发现，违反直觉的非辐射模式的增益更高。这是用当模式从等离子转换为光子的特征时发生的场分布的变化来解释的。最后，我们通过使用现实主义者增益培养基来评估提案的可行性，并表明研究系统的刺激排放需要相对较低的种群反转。
There is increasing interest in filling the gap of miniaturized terahertz/mid-infrared radiation sources and, particularly, in incorporating these sources into micro/nanophotonic circuits. By using rigorous electromagnetic methods, we investigate the lasing conditions and the electric-tunability of radiative and non radiative propagating surface-plasmon modes in cylinders made of active materials coated with a graphene layer. A detailed analysis of the lasing condition of different surface-plasmon modes shows that there is an abrupt change in the gain required when modes become nonradiative. Although radiative modes, subject to both radiation and ohmic losses, are expected to require more gain compensation than nonradiative modes, we find that, counterintuitively, gain compensation is greater for nonradiative modes. This is explained in terms of a change in the distribution of fields that occurs when the character of modes switches from plasmonic to photonic. Finally, we assess the feasibility of our proposal by using a realist gain medium and showing that a relatively low population inversion is required for the stimulated emission of the studied system.
