Non-Hermitian Photonics via an Optical Meta-Molecule

Abstract

In this talk I will cover recent theoretical work on how to build and dissect the new photonic-meta-atom of the non-Hermitian photonics that consists of two optically coupled gain blocks individually addressed so that pump inhomogeneities can induce the gain and loss requirement. This radically simple nonlinear rate equation model1 includes strong phase amplitude coupling and optical frequency detuning. Within the context of the corresponding evolution equations we identified the spectral line-shape, spectral transition properties and showed that exceptional points occur under general conditions, not restricted by parity-time-symmetry as in the case of coupled mode models, thus promoting a paradigm shift in the field of non-Hermitian photonics. The optical signatures of system bifurcations such as Hopf bifurcations and exceptional points2 and bifurcation points are manifested in the spectral line shape through the emergence of side bands and intensity peaks, respectively are manifested in terms of self-termination effects and observable characteristics of the spectral line shape that can be radically controlled in terms of optical frequency detuning and inhomogeneous pumping. We essentially found that the fundamental active photonic dimer is an object like the split-ring resonator of metamaterials, this meta-atom is rich and complex with a convoluted stability diagram in space of optical coupling and frequency detuning, allowing of new designs for photonic integrated circuits. Paving the way to a proper, simple and powerful way of designing a new set of experiments to probe the functionality and reconfigurability of photonic integrated circuits, that can be used as center blocks for ultra sensitive sensors3, tunable photonic oscillators4, topological insulator lasers5, topologically active arrays6 as well the far-field patterns of phased arrays of photonic emitters7 Additionally we will argue that these explorations may be the springboard for designing the next generation of photonically integrated oscillators that emit at will diverse waveforms for chip scale laser radar and microwave photonic applications as well investigating novel collective dynamics including turbulent chimeras8, to eventually usher the era of photonic analog processors9.