Photonic molecules and spectral engineering

TL;DR

This paper reviews the optical properties and applications of photonic molecules, emphasizing their tunability, physical regimes exploration, and recent advances enabling their use in quantum and classical technologies.

Contribution

It provides a comprehensive overview of photonic molecules, highlighting recent design innovations and their potential for advanced optical and quantum applications.

Findings

Photonic molecules enable lowered laser thresholds.

They produce directional light emission.

They enhance sensitivity in various sensors.

Abstract

This chapter reviews the fundamental optical properties and applications of pho-tonic molecules (PMs) - photonic structures formed by electromagnetic coupling of two or more optical microcavities (photonic atoms). Controllable interaction between light and matter in photonic atoms can be further modified and en-hanced by the manipulation of their mutual coupling. Mechanical and optical tunability of PMs not only adds new functionalities to microcavity-based optical components but also paves the way for their use as testbeds for the exploration of novel physical regimes in atomic physics and quantum optics. Theoretical studies carried on for over a decade yielded novel PM designs that make possible lowering thresholds of semiconductor microlasers, producing directional light emission, achieving optically-induced transparency, and enhancing sensitivity of microcavity-based bio-, stress- and rotation-sensors. Recent advances in material science and nano-fabrication techniques make possible the realization of optimally-tuned PMs for cavity quantum electrodynamic experiments, classical and quantum information processing, and sensing.