Non-reciprocal nonlinear optic induced transparency and frequency conversion on a chip

TL;DR

This paper demonstrates on-chip non-reciprocal optical transparency and efficient frequency conversion using coherent photon-photon interactions enabled by second-order nonlinearity in aluminum nitride photonic devices.

Contribution

It reports the first experimental observation of coherent photon-photon interaction and non-reciprocal transparency on an integrated platform using  nonlinearity.

Findings

Non-reciprocal nonlinear optic induced transparency achieved.

Near-unit internal efficiency in wide-band frequency conversion.

Bandwidth of frequency conversion up to 0.76 GHz.

Abstract

Developments in photonic chips have spurred photon based classical and quantum information processing, attributing to the high stability and scalability of integrated photonic devices [1, 2]. Optical nonlinearity [3] is indispensable in these complex photonic circuits, because it allows for classical and quantum light sources, all-optical switch, modulation, and non-reciprocity in ambient environments. It is commonly known that nonlinear interactions are often greatly enhanced in the microcavities [4]. However, the manifestations of coherent photon-photon interaction in a cavity, analogous to the electromagnetically induced transparency [5], have never been reported on an integrated platform. Here, we present an experimental demonstration of the coherent photon-photon interaction induced by second order optical nonlinearity (\chi^{(2)} ) on an aluminum nitride photonic chip. The non-reciprocal nonlinear optic induced transparency is demonstrated as a result of the coherent interference between photons with different colors: ones in the visible wavelength band and ones in the telecom wavelength band. Furthermore, a wide-band frequency conversion with an almost unit internal (0.14 external) efficiency and a bandwidth up to 0.76\,\mathrm{GHz} is demonstrated.