Doronin I V, Zyablovsky A A, Andrianov E S
Opt Express. 2021 Feb 15;29(4):5624-5634. doi: 10.1364/OE.417354.
The creation of nanoscale lasers that operate above a coherent threshold is a challenging problem. We propose a way to circumvent this issue using systems in which a strong coupling regime is achieved between the light and the active medium. In the strong coupling regime, energy oscillations take place between the EM field in the cavity and the atoms. We show that by applying appropriate time modulation to the pumping, it is possible to control these energy oscillations in such a way that coherence in the laser system appears below the lasing threshold. In this approach, the radiation linewidth is two orders of magnitude smaller than the linewidth of a conventional laser for the same photon number. In addition, the second order coherence function of the output radiation is reduced from two to one before the system reaches a positive population inversion. Our results pave the way for the creation of nanoscale sources of coherent radiation that can operate below the lasing threshold.
制造工作在相干阈值以上的纳米级激光器是一个具有挑战性的问题。我们提出了一种方法来规避这个问题，即使用在光与活性介质之间实现强耦合 regime 的系统。在强耦合 regime 中，腔内的电磁场与原子之间会发生能量振荡。我们表明，通过对泵浦施加适当的时间调制，可以控制这些能量振荡，使得激光系统中的相干性在激光阈值以下出现。在这种方法中，对于相同的光子数，辐射线宽比传统激光器的线宽小两个数量级。此外，在系统达到正粒子数反转之前，输出辐射的二阶相干函数从二降低到一。我们的结果为制造可在激光阈值以下工作的相干辐射纳米级源铺平了道路。
