Tunable nanophotonics
Juejun Hu, Arseniy I. Kuznetsov, Volker J. Sorger, Isabelle Staude · Nanophotonics · 2022
Most optical elements -be it refractive lenses, optical coatings, or glass fibers -have their attributes fully defined once they are fabricated.Moving or swapping bulky parts often becomes the only resort to enable dynamic tuning of an optical system to adapt to changing needs, which however escalates the system size, weight, complexity, and cost.The emergence of nanophotonics offers an unprecedented opportunity to realize tunable photonic systems.Through locally applying electrical, thermal, optical, or magnetic stimuli to change material properties, the optical functions of a nanophotonic device can be efficiently modulated with high speed, minimal power consumption, enhanced ruggedness, all awhile offering an ultracompact footprint.This unique capability foresees the widespread adoption of tunable nanophotonics in analog computing [1], high-speed communications [2], optical spectroscopy [3], computational imaging [4], beam steering [5], display technologies [6], optical zoom [7], nonreciprocal photonics [8], and numerous other applications of the looming Industry-4.0 era.This special issue on "tunable nanophotonics" surveys this rapidly evolving field with emphases on novel active tuning mechanisms as well as emerging applications of reconfigurable nanophotonic devices.In their perspective article, Thureja et al. offer their viewpoint on technical pathways toward a "universal metasurface" capable of on-demand dynamically reconfigurable wavefront control.Fan et al. review the state-of-the-art of tunable metamaterials, introducing both fundamental concepts and latest advances in active tuning strategies.Ferreira de Lima et al. discuss automated design and control methods in reconfigurable neuromorphic photonic processors to