2017/02/21 by Christopher W. Peterson, Seunghwi Kim, Peterson, Christopher W +5
Physics and Astronomy · Engineering · #Mechanical and Optical Resonators #Quantum optics and atomic interactions #Photonic and Optical Devices
paper · pdf · doi:10.48550/arxiv.1702.06476
Inducing nonreciprocal wave propagation is a fundamental challenge across a\nwide range of physical systems in electromagnetics, optics, and acoustics.\nRecent efforts to create nonreciprocal devices have departed from established\nmagneto-optic methods and instead exploited momentum based techniques such as\ncoherent spatiotemporal modulation of resonators and waveguides. However, to\ndate the nonreciprocal frequency responses that such devices can achieve have\nbeen limited, mainly to either broadband or Lorentzian-shaped transfer\nfunctions. Here we show that nonreciprocal coupling between waveguides and\nresonator networks enables the creation of devices with customizable\nnonreciprocal frequency responses. We create nonreciprocal coupling through the\naction of synthetic phonons, which emulate propagating phonons and can scatter\nlight between guided and resonant modes that differ in both frequency and\nmomentum. We implement nonreciprocal coupling in microstrip circuits and\nexperimentally demonstrate both elementary nonreciprocal functions such as\nisolation and gyration as well as reconfigurable, higher-order nonreciprocal\nfilters. Our results suggest nonreciprocal coupling as platform for a broad\nclass of customizable nonreciprocal systems, adaptable to all wave phenomena.\n