Basic concepts, advances and emerging applications of nanophotonics

Nanophotonics includes a diverse set of nontrivial physical processes, such as radiation-matter interaction, near-field optical microscopy, and the fabrication of nanophotonic materials, which extend far beyond diffraction limits. These effects have created new opportunities for a number of applications in nonlinear optics, light harvesting, media transmission, optical and biosensing, luminescence, and display technology. Emerging technologies in numerous optical systems, involving photon interaction with nanostructured materials at extremely small scales play a crucial role in improving our daily lives. The goal along this line is to develop nanometer-sized devices and equipment for efficient control and influence of photonic processes, in addition to slowing down the speed of photons. The industrial revolution has greatly impacted this multidisciplinary discipline, allowing researchers to discover new avenues in design, applied science, chemistry, physical science, and biological technology. This review familiarizes readers with the basic concepts of photonic nanostructures, including photonic nanoscale interactions, nanoconfinement, characteristics of nonlinear optical phenomena, and the use of photonic nanostructures in innovative domains such as light harvesting, theragnostic, metasurfaces, photovoltaics and plasmonics applications.