Integrated photonic nonreciprocal devices based on susceptibility-programmable medium

TL;DR

This paper proposes a programmable optical medium with tunable susceptibility for integrated photonic devices, enabling reconfigurable nonreciprocal effects and optical isolation through structured optical pumping and atomic interactions.

Contribution

It introduces a susceptibility-programmable medium based on polarizable atoms, allowing dynamic control of optical responses for nonreciprocal photonic devices.

Findings

The medium's susceptibility can be spatially and temporally programmed.

Reconfigurable optical isolation is theoretically demonstrated.

Potential applications in integrated photonics are highlighted.

Abstract

The switching and control of optical fields based on nonlinear optical effects are often limited to relatively weak nonlinear susceptibility and strong optical pump fields. Here, an optical medium with programmable susceptibility tensor based on polarizable atoms is proposed. Under a structured optical pump, the ground state population of atoms could be efficiently controlled by tuning the chirality and intensity of optical fields, and thus the optical response of the medium is programmable in both space and time. We demonstrate the potential of this approach by engineering the spatial distribution of the complex susceptibility tensor of the medium in photonic structures to realize nonreciprocal optical effects. Specifically, we investigate the advantages of chiral interaction between atoms and photons in an atom-cladded waveguide, theoretically showing that reconfigurable, strong, and fastly switchable isolation of optical signals in a selected optical mode is possible. The susceptibility-programmable medium provides a promising way to efficiently control the optical field, opening up a wide range of applications for integrated photonic devices and structured optics.