Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY, 10027, USA.
School of Electrical and Computer Engineering, Cornell University, Ithaca, NY, 14853, USA.
Nat Commun. 2020 Aug 17;11(1):4119. doi: 10.1038/s41467-020-17919-6.
The need for solving optimization problems is prevalent in various physical applications, including neuroscience, network design, biological systems, socio-economics, and chemical reactions. Many of these are classified as non-deterministic polynomial-time hard and thus become intractable to solve as the system scales to a large number of elements. Recent research advances in photonics have sparked interest in using a network of coupled degenerate optical parametric oscillators (DOPOs) to effectively find the ground state of the Ising Hamiltonian, which can be used to solve other combinatorial optimization problems through polynomial-time mapping. Here, using the nanophotonic silicon-nitride platform, we demonstrate a spatial-multiplexed DOPO system using continuous-wave pumping. We experimentally demonstrate the generation and coupling of two microresonator-based DOPOs on a single chip. Through a reconfigurable phase link, we achieve both in-phase and out-of-phase operation, which can be deterministically achieved at a fast regeneration speed of 400 kHz with a large phase tolerance.
解决优化问题的需求在各种物理应用中都很普遍，包括神经科学、网络设计、生物系统、社会经济和化学反应。其中许多问题被归类为非确定性多项式时间难题，因此随着系统规模扩大到大量元素，这些问题变得难以解决。最近光子学的研究进展引起了人们的兴趣，即使用耦合简并光学参量振荡器（DOPO）网络来有效地找到伊辛哈密顿量的基态，通过多项式时间映射，可以用它来解决其他组合优化问题。在这里，我们利用纳米光子学的氮化硅平台，展示了一种使用连续波泵浦的空间多路复用 DOPO 系统。我们在单个芯片上实验演示了两个基于微谐振器的 DOPO 的产生和耦合。通过可重构的相位链路，我们实现了同相和异相操作，在 400 kHz 的快速再生速度下，可以实现确定性操作，并且具有较大的相位容限。
