A nanophotonic laser on a graph

TL;DR

This paper introduces a nanophotonic network based on interference and multiple paths, enabling localized modes and mirror-less lasing, which can be designed via network topology for advanced laser applications.

Contribution

It presents a novel nanophotonic network architecture using a graph-based Maxwell's equation solution, allowing tailored light localization and lasing through network design.

Findings

Network sustains localized modes and mirror-less light trapping.

Lasing with ~100 pm linewidth achieved in the network.

Design of optical modes is controllable via network topology.

Abstract

Conventional nano-photonic schemes minimise multiple scattering to realise a miniaturised version of beam-splitters, interferometers and optical cavities for light propagation and lasing. Here instead, we introduce a nanophotonic network built from multiple paths and interference, to control and enhance light-matter interaction via light localisation. The network is built from a mesh of subwavelength waveguides, and can sustain localised modes and mirror-less light trapping stemming from interference over hundreds of nodes. With optical gain, these modes can easily lase, reaching $\sim$100 pm linewidths. We introduce a graph solution to the Maxwell's equation which describes light on the network, and predicts lasing action. In this framework, the network optical modes can be designed via the network connectivity and topology, and lasing can be tailored and enhanced by the network shape. Nanophotonic networks pave the way for new laser device architectures, which can be used for sensitive biosensing and on-chip optical information processing.