Because of the scaling of light-matter interaction with the confinement of the electromagnetic field, close to diffraction-limited, dielectric resonators are the cornerstone of novel photonic devices and fundamental research. The availability of advanced fabrication technologies has motivated strategies for optimal design, whereas efficient computing and genetic algorithms are used to tackle the many degrees of freedom available. Other strategies attempt harnessing disorder and imperfections to achieve ultimate optical confinement.
Here we will discuss a radically different approach: quasi-periodic photonic structures, governed by a very reduced set of parameters, already providing much desired features for novel devices but also for studying fundamental interaction. In order to illustrate this concept I will discuss a few examples: optical parametric oscillators, optomechanics and silicon photonics.