Integrated Metasurfaces for Advanced Solid-State-Lighting

Light-Emitting Diodes (LEDs) exhibit a typical Lambertian emission, usually requiring reshaping by means of secondary optics. We review the potential of various integrated photonic architectures to address the demand for system miniaturization and high efficiency in emerging applications. Photonic structures that can be potentially integrated in LED devices include metalenses, photonic crystals and reflective metasurfaces. We embed periodic nanoantennas in InGaN/GaN multi-quantum well (MQW) LEDs to control their far-field emission directionality and enhance collection efficiency. We propose exploiting mechanisms such as surface lattice resonances, which rely on the near-field coupling between the quantum wells and the nanoantenna array. Multiple experimental and modeling studies demonstrate the benefits and challenges of optimized integrated metasurfaces to enable efficient SSL sources without the need of bulky secondary optics for directional beam control.