Novel phenomena in gain-enhanced nanophotonics
In this talk I will discuss two examples of the novel phenomena that emerge by incorporating active (gain) media into conventional nanophotonic systems. First, I will present a theoretical analysis of lasing action in photonic crystal surface-emitting lasers. It will be shown that the excitation of dark Fano resonances -- featuring arbitrarily large quality factors -- can lead to a significant reduction of the lasing threshold with respect to conventional vertical-cavity surface-emitting lasers. The second part of the talk will be devoted to present our recent results on the amplification of extraordinary optical transmission phenomena in periodic arrays of subwavelength apertures incorporating optically-pumped gain media. It will be demonstrated computationally that the resonant electric-field enhancement present in the considered structures enables reaching complete ohmic loss compensation at moderate pump intensity levels. A discussion of the feasibility of reaching lasing action in this class of systems will also be provided.