About this Research Topic
Metaphotonics is already more than two decades old, but it is still dynamically expanding and growing. The prefix ‘meta’ means beyond; as such, metaphotonics primarily deals with the design and use of engineered structures and materials for controlling and molding the flow of electromagnetic and light waves in an unconventional way that is not found in nature, particularly at nanoscopic dimensions—thereby bridging the gap between optics and nanotechnology. These judiciously designed artificial structured matter enable harnessing both electric and magnetic interactions with the ‘meta-atoms’ of the medium, giving rise to spectacular phenomena, including negative index of refraction, subwavelength imaging, invisibility cloaking, ‘slow’ and stopped light, one-way propagation, and many more. Significant advances in nanotechnology have underpinned the emergence and establishment of fundamental and applied research on metaphotonics.
Through the engineering of the refractive index and its spatial gradients via subwavelength structuring of materials, metaphotonics exploits, with unprecedented control, the degrees of freedom of light (amplitude, phase, polarization, bandwidth, direction of propagation, etc.). While metaphotonics has been emerging with a great potential to replace or go beyond traditional optics and photonics, there are still challenges in several aspects. Fundamentally, directing, guiding and focusing light with high efficiency on the nanoscale is still an unresolved challenge, and so is the fabrication and large-scale modelling of three-dimensional metastructures. Moreover, material designs are currently being exploited with a variety of potential architectures such as atomic, organic, inorganic, nanoparticle-based, biological, and switchable materials, as well as with advanced design strategies based on, for example, artificial intelligence for new metaphotonic structures that have never been explored. Such new directions in metaphotonics help to obtain new physical insights, extend the range of design parameters way further than is achievable today, and accelerate practical applications. Application-wise, there are lots of ongoing efforts to address long-standing problems, such as identifying low-loss nanophotonic media below the diffraction limit, broadband cloaking of large arbitrary objects, prolonged slowing (‘buffering’) of broadband waves, etc. Furthermore, there are many potential applications of metaphotonics that will bring breakthroughs to society, for example, optical communications, solar energy harvesting, biophotonics, light guiding using transformation optics, display and sensor technologies, flat optics nanotechnology, and many more. This special issue aims to collect recent advances in metaphotonics research on various aspects ranging from fundamentals to applications.
We are interested in inviting the submission of original research, review, mini review, and perspective articles on metaphotonics research from fundamentals to applications, including but not limited to the themes listed below:
● Plasmonic and dielectric metastructures
● Metamaterials and metasurfaces
● Metaphotonics for 2D materials
● Machine learning and inverse design for metaphotonics
● Topological, non-Hermitian and unidirectional photonics
● Nonlinear and quantum metaphotonics
● Active, gain-enhanced, and reconfigurable metadevices
● Metaphotonics-enabled optical sensing, imaging, and microscopy
● Biophotonics with metaphotonics
Keywords: Metaphotonics, Plasmonic Metastructures, Dielectric Metastructures, Machine Learning and Metaphotonics Design, Metadevices, Non-Hermitian Photonics, Topological Photonics
Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.