In a significant stride for integrated photonics, a team of researchers from various institutions, including the University of Bari, the Italian Institute of Technology, and the National Research Council of Italy, has developed a novel platform for low-power, highly nonlinear optical circuits. Their work, published in the journal Nature Photonics, focuses on the potential of exciton-polaritons, hybrid light-matter excitations, to overcome the limitations of conventional materials in photonic integrated circuits.
Photonic integrated circuits are pivotal for compact and energy-efficient optical information processing. However, their practical implementation has been hindered by the weak optical nonlinearities of conventional materials, which require high power and large footprints to achieve significant nonlinear responses. Exciton-polaritons, which combine strong optical nonlinearities with the high speed and large scalability typical of photonic devices, offer a promising solution. Until now, working on-chip polaritonic elements demonstrating room temperature coherent lasing, controllable nonlinear propagation, or amplification have remained elusive.
The researchers have demonstrated a fully integrated perovskite polaritonic circuit that addresses these challenges. Using a single-step microfluidic lithographic technique, they created waveguide circuits with integrated gratings that simultaneously act as couplers and mirrors, forming in-plane Fabry-Pérot cavities. These structures support robust in-plane polariton lasing between gratings, yielding coherent emission along the waveguide.
Moreover, the team observed clear signatures of strong nonlinear self-phase modulation and, for the first time, optical amplification of guided polaritons at room temperature. This breakthrough opens the way for low-power, highly nonlinear optical circuits for integrated photonics and neuromorphic architectures operating at room temperature.
The practical applications for the energy sector are substantial. These integrated circuits could lead to more energy-efficient data centers and high-performance computing systems, which are increasingly vital for the energy industry’s data-driven operations. Additionally, the technology could enhance optical communication systems, improving the efficiency and speed of data transmission, which is crucial for smart grid management and renewable energy integration.
The researchers’ innovative approach and the promising results they have achieved represent a significant step forward in the field of integrated photonics. Their work not only advances our understanding of exciton-polaritons but also paves the way for more efficient and powerful optical technologies in the energy sector and beyond.
Source: Nature Photonics
This article is based on research available at arXiv.