Cavity-Electro-Optomechanical Circuits with Broken Time-Reversal Symmetry

光通常在双向街道中传播-如果它经历反射，则向前传播的光伴随着向后传播的光。为了消除后向传播的表亲，需要光的时间反演对称破缺。这是具有挑战性的，因为光子-光的量子-不携带电荷，因此不与磁场相互作用，磁场是带电粒子（如电子）的时间反演对称性破缺背后的力。无反射光传播对于光信息通信是重要的，特别是对于稳定激光频率和减轻信号衰减。在小型化设置中，今天的集成光子微芯片使用低功率和宽带光学元件来执行传统电子对应物无法实现的信息处理和通信。就像光网络一样，光子微芯片的正常功能也受益于消除反射的设备。这些器件（所谓的光隔离器）的芯片级实现仍然是一个突出的挑战。众所周知，通过诱导介质折射率的时间调制，可以打破光的时间反演对称性。这种时间调制的有效手段可以通过在光学介质中激发声波来实现，该声波扰动局部电极化密度。在这种情况下，该计划将探索由光与机械运动之间的相互作用引起的时间反演对称性破缺，并研究在微芯片上实现的人工光机结构中的非互易光传播和相关的新物理。这项工作的潜在更广泛的影响主要在于为集成光子技术开发新的器件和方法，通过实践研究和新课程对学生进行这一重要领域的教育，以及通过新一代光电产品提高社会效益。拟议的计划旨在开发具有破时反转对称性的集成光子电路的创新系列，通过耦合电光机械谐振器中的辐射压力来实现。腔光学机械系统，涉及耦合的光强度的机械运动通过辐射压力在波长尺度上，创建明确的时间反演对称性破缺所需的大的光学非线性。使用相位相关参量光泵控制单个腔突出了可编程合成场的方法，这导致光学和声学的非互易性，甚至可能揭示大规模光机械结构中的拓扑波干涉。压电驱动稳态机械运动，在多模光机械腔中诱导光子跃迁，作为打破时间反演对称性的另一种手段，可以用来提高腔-电-光机械电路的带宽，使其超过机械阻尼率。这项工作最突出的将是研究电光机械电路中的非互易光子-声子相互作用，并实现重要的光子器件应用，包括非磁性循环器和鲁棒延迟线。本课程亦将探讨由机械运动所驱动的光机晶体中具有拓扑性质的新物理。该提案的智力价值主要在于开发纳米光子网络架构的新范式，这将开启从光学NEMS到拓扑光力学的新研究路线，并实现微波光子学，通信，该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准。

Light generally travels in two-way streets - a forward propagating light is accompanied by a backward propagating light if it undergoes reflection. To eliminate the backward propagating cousin requires time-reversal symmetry breaking of light. This is challenging because photons - the quanta of light- do not carry charge and thus do not interact with magnetic fields which are the force behind time-reversal symmetry breaking of charged particles, such as electrons. Reflection-free light propagation is important to optical information communications, in particular for stabilizing laser frequencies and mitigating signal decay. In a miniaturized setting, today's integrated photonic microchips use low-power and broadband optical elements to perform information processing and communication unavailable with conventional electronic counterparts. Just like an optical network, the proper functioning of the photonic microchips also benefits from reflection-eliminating devices. The chip-scale realization of these devices, so called optical isolators, remains an outstanding challenge. It is known that time-reversal symmetry of light can be broken by inducing time-modulation of media's refractive index. An effective means of such time-modulation can be achieved by exciting acoustic waves in the optical media which perturb local electric polarization density. In this context, this program will explore time-reversal symmetry breaking induced by the interaction between light and mechanical motion, and study non-reciprocal light propagation and associated new physics in artificial optomechanical structures realized on microchips. The potential broader impact of this work lies primarily in the development of new devices and methodologies for integrated photonic technologies, in the education of students in this important field through hands-on research and new courses, and in the improvement of societal benefits with new generations of optoelectronic products.The proposed program aims at developing an innovative family of integrated photonic circuits with broken time-reversal symmetry, enabled by radiation pressure force in coupled electro-optomechanical resonators. Cavity-optomechanical systems, involving the coupling of light intensity to mechanical motion via radiation pressure at wavelength scale, create the requisite large optical nonlinearities for explicitly time-reversal symmetry breaking. The use of phase-correlated parametric optical pumps for controlling individual cavities highlights the approach of programmable synthetic fields, which leads to optical and acoustic nonreciprocity, and may even reveal topological wave interference in large-scale optomechanical structures. Piezoelectric driving of steady state mechanical motion, for inducing photonic transition in multimode optomechanical cavities as another means to break time-reversal symmetry, can be used to boost the bandwidth of cavity-electro-optomechanical circuits beyond the mechanical damping rate. Most prominent of this work will be studying nonreciprocal photon-phonon interactions in electro-optomechanical circuits, and realizing important photonic device applications including non-magnetic circulators and robust delay lines. New physics bearing topological properties in optomechanical crystals driven by mechanical motion will also be investigated. The intellectual merit of this proposal lies primarily in the development of a new paradigm of nanophotonic network architecture that will unlock new lines of research, from optical NEMS to topological optomechanics, and enable transformative technologies for microwave photonics, communications, and quantum information.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.