Active Nanophotonics

TL;DR

Recent advances in nanofabrication have propelled active nanophotonics, enabling ultrafast, low-energy optical devices that overcome fundamental challenges like losses and diffraction through gain materials and engineered nanostructures.

Contribution

This paper reviews recent developments in active nanophotonics, focusing on nanodevices for lasing, loss compensation, and novel optical functionalities using engineered gain and loss distributions.

Findings

Progress in nanofabrication enables ultrafast, low-energy nanophotonic devices.

Active nanophotonics can realize PT-symmetry and exceptional points.

Engineered gain/loss distributions lead to new optical functionalities.

Abstract

Recent progress in nanofabrication has led to tremendous technological developments in nanophotonics, which rely on the interaction of light with nanostructured matter. Nanophotonics has experienced a large surge of interest in recent years, from basic research to applied technology. The increased importance of extremely low-energy data processing at ultra-fast speeds has been encouraging the use of light for signal transport and processing. Energy demands and interaction time scales become smaller with the physical size of the nanostructures, hence nanophotonics opens the opportunity of integrating a large number of devices that can generate, control, modulate, sense and process light signals at ultrafast speeds and below femtojoule/bit energy levels. However, losses and diffraction pose fundamental challenges to the fundamental ability of nanophotonic structures to confine light efficiently in smaller and smaller volumes. In this framework, active nanophotonics, which combines the latest advances in nanotechnology with gain materials has become in recent years a vital area of optics research, both from the physics, material science, and engineering standpoint. In this paper, we review recent efforts in enabling active nanodevices for lasing and optical sources, loss compensation, and to realize new optical functionalities, like PT-symmetry, exceptional points and nontrivial lasing based on suitably engineered distributions of gain and loss in nanostructures.