论文标题
在特殊点运行的光学放大器中量子噪声的非通道性
Non-universality of quantum noise in optical amplifiers operating at exceptional points
论文作者
论文摘要
最近提出了基于特殊点的光学放大器(EPOAS)的概念,作为将光学放大器微型化的新范式提出的,同时增强其增益带宽产品。尽管这个新的放大器家族在经典域中的操作提供了明显的优势,但尚未评估它们在量子域中的性能。特别是,尚不清楚真空波动引入的量子噪声如何影响其操作。在这里,我们通过考虑依赖于单向耦合,平等时间(PT)对称性或用于实现特殊点(EP)的粒子孔对称性的三种原型EPOAS结构来研究这个问题。通过使用Heisenberg-Langevin形式主义,我们计算了每个设备中的附加量子噪声,并将其与不涉及任何特殊点的量子限制放大器方案进行了比较。我们的分析揭示了几个有趣的结果:最值得注意的是,尽管某些EPOA的量子噪声可以与与常规放大器系统相关的量子相媲美,但通常,噪声并没有遵循通用缩放,这是特殊点的函数,而是从一个实现到另一个实现的变化。
The concept of exceptional points-based optical amplifiers (EPOAs) has been recently proposed as a new paradigm for miniaturizing optical amplifiers while simultaneously enhancing their gain-bandwidth product. While the operation of this new family of amplifiers in the classical domain provides a clear advantage, their performance in the quantum domain has not yet been evaluated. Particularly, it is not clear how the quantum noise introduced by vacuum fluctuations will affect their operation. Here, we investigate this problem by considering three archetypal EPOAs structures that rely either on unidirectional coupling, parity-time (PT) symmetry, or particle-hole symmetry for implementing the exceptional point (EP). By using the Heisenberg-Langevin formalism, we calculate the added quantum noise in each of these devices and compare it with that of a quantum-limited amplifier scheme that does not involve any exceptional points. Our analysis reveals several interesting results: most notably that while the quantum noise of certain EPOAs can be comparable to those associated with conventional amplifier systems, in general the noise does not follow a universal scaling as a function of the exceptional point but rather varies from one implementation to another.