Spotlight on "Surface nanoscale axial photonics: robust fabrication of high-quality-factor microresonators"

Trapping electrons dynamically in a three dimensional microscopic volume by means of artificial potential barriers is a relatively simple task. Indeed, this is what happens inside any electronic device we use in everyday life. Unfortunately, the same thing cannot be said about photons. The problem of harnessing photons effectively in a small volume and for a long time has always attracted the attention of scientists since the very first origins of optics. However, today it is still hard to predict if a photonic counterpart of present micro and nanoelectronic devices, like random access memories, and ultimately processors, will ever exist. Although being far from giving an answer, much progress has taken place in recent years on the realization of photonic platforms where the light flow can be controlled with large flexibility through microscale optical devices. The problem of light trapping is inherently related to the possibility of slowing down the velocity of light. Two main approaches have proved to be effective for realizing slow light in a photonic chip, based on the use of ring resonators and photonic crystals waveguides, respectively. The maturity of these platforms has rapidly improved in the last decade, and now architectures with increased complexity and broadened functional capability can be fabricated.