Bi Weilin, Zhang Xin, Yan Meng, Zhao Lina, Ning Tingyin, Huo Yanyan
Opt Express. 2021 Apr 12;29(8):12634-12643. doi: 10.1364/OE.420001.
High-Q factor can enhance the interaction between light and matter, which is an important parameter to decrease the threshold of nanolasers. Here, we theoretically propose an eccentric nanoring structure with a high and controllable Q factor to realize a low-threshold and controllable nanolaser by amplifying the quasi-bound states in the continuum (quasi-BIC). The designed nanostructure supports a quasi-BIC because of the symmetry protection-breaking of the nanostructure. The quasi-BIC has a very high Q factor of about 9.6×10 and can also be adjusted by changing structural parameters. We use the energy level diagram of the four-level two-electron system to study the lasing action of the eccentric nanoring structure. The results show that the nanolaser has a relatively low threshold of about 6.46 μJ/cm. Furthermore, the lasing behavior can be tuned by controlling the structural parameters of the eccentric circular ring structure.
高品质因数可以增强光与物质之间的相互作用，这是降低纳米激光器阈值的一个重要参数。在此，我们从理论上提出一种具有高且可控品质因数的偏心纳米环结构，通过放大连续态中的准束缚态（准BIC）来实现低阈值且可控的纳米激光器。由于纳米结构的对称性保护被打破，所设计的纳米结构支持一个准BIC。该准BIC具有约9.6×10的非常高的品质因数，并且还可以通过改变结构参数来进行调节。我们利用四能级双电子系统的能级图来研究偏心纳米环结构的激光作用。结果表明，该纳米激光器具有约6.46 μJ/cm的相对较低阈值。此外，激光行为可以通过控制偏心圆环结构的结构参数来进行调节。
