Optics InfoBase

It is demonstrated that higher-order plasmonic modes in the split-ring resonators (SRRs) are strongly enhanced when SRRs are arranged in a densely spaced two-dimensional array. The mode enhancement results from the near-field electrical coupling between the adjacent resonators. The effect is most pronounced in narrow gap SRRs which allows to observe experimentally plasmon modes up to the seventh order. In the array of narrow gap SRRs, the fifth-order resonance demonstrates high Q-factor, high resonance strength and wide tunability which opens up attractive features for practical applications of planar SRR structures.

We present the observation of optical coupling in terahertz microdisk molecules based on quantum-cascade lasers and its tunability by the applied electric field. The spectral behaviour is in good accordance with performed Finite-Difference Time-Domaine simulations.

We present microdisk terahertz quantum-cascade lasers with dimensions comparable to the spatial mode distribution inside the microcavity and present 3-D Finite-Difference Time-Domaine simulations which are in good agreement with our experimental findings.