Hillbrand Johannes, Auth Dominik, Piccardo Marco, Opačak Nikola, Gornik Erich, Strasser Gottfried, Capasso Federico, Breuer Stefan, Schwarz Benedikt
Institute of Solid State Electronics, TU Wien, Gusshausstrasse 25-25a, 1040 Vienna, Austria.
John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA.
Phys Rev Lett. 2020 Jan 17;124(2):023901. doi: 10.1103/PhysRevLett.124.023901.
Coupled clocks are a classic example of a synchronization system leading to periodic collective oscillations. Already in 1665, Christiaan Huygens described this phenomenon as a kind of "sympathy" among oscillators. In this work, we describe the formation of two types of laser frequency combs as a system of oscillators coupled through the beating of the lasing modes. We experimentally show two completely different types of synchronization in a quantum dot laser-in-phase and splay-phase states. Both states can be generated in the same device, just by varying the damping losses of the system. This modifies the coupling among the oscillators. The temporal laser output is characterized using both linear and quadratic autocorrelation techniques. Our results show that both pulses and frequency-modulated states can be generated on demand within the same device. These findings allow us to connect laser frequency combs produced by amplitude-modulated and frequency-modulated lasers and link these to pattern formation in coupled systems such as Josephson-junction arrays.
耦合时钟是导致周期性集体振荡的同步系统的一个经典例子。早在1665年，克里斯蒂安·惠更斯就将这种现象描述为振荡器之间的一种“共鸣”。在这项工作中，我们将两种类型的激光频率梳的形成描述为一个通过激光模式的拍频耦合的振荡器系统。我们通过实验展示了量子点激光器中两种完全不同类型的同步——同相和张开相状态。这两种状态都可以在同一器件中产生，只需改变系统的阻尼损耗即可。这会改变振荡器之间的耦合。使用线性和二次自相关技术对激光的时间输出进行表征。我们的结果表明，在同一器件中可以按需产生脉冲和调频状态。这些发现使我们能够将调幅和调频激光器产生的激光频率梳联系起来，并将它们与诸如约瑟夫森结阵列等耦合系统中的图案形成联系起来。
