Engineering the density of photonic states with electromagnetic modes has become an attractive approach for controlling energy transfer between molecular systems. Here we report the use of surface lattice resonances (SLRs) that arise in arrays of metal-insulator-metal (MIM) nanocylinders to control the energy transfer between two archetypal molecular dyes, P580 ( donor) and P650 (acceptor). When the SLR is detuned from the donor emission, energy transfer is observed as expected, with donor emission decreasing with respect to the acceptor emission (donor/ acceptor peak fluorescence ratio = 0.45). In contrast, when the SLR is tuned to the donor emission, Purcell enhancement becomes dominant, outcompeting energy transfer and suppressing acceptor emission (donor/acceptor peak fluorescence ratio = similar to 5.4). To analyze these observations, a kinetic model was developed, based on pumping rate, donor-to-acceptor energy transfer rate, and radiative and nonradiative decay of the dyes. The results suggest the additional decay channel introduced by the SLR for which lambda(SLR)(k parallel to)= 0 = lambda(donor)(emission) competes strongly with the energy transfer process, while SLRs that coincide with donor emission peaks at larger values of in-plane momentum k(parallel to) have a less pronounced effect. Our study highlights the wide range of SLR-based Purcell effects possible by simple changes in the lattice dimensions and their consequences in the kinetics of molecular energy transfer processes in the condensed phase.

When we illuminate gold nanofluids over indium-tin-oxide (ITO)-coated substrates, nanoparticle chains selfassemble via optical binding forces. We speculate that charge transfer between gold and ITO pins nanoparticles to the substrate and reduces the lateral Brownian motion as they attach to the substrate. We correspondingly model the self-assembly with additional stochastic or random forces. Simulations show a nonequilibrium-phase transition: when the stochastic force is small, nanoparticle chains align perpendicular to the light polarization and nanoparticles settle at shallow but stable nodes; when the stochastic force is large, however, the nanoparticle chains align parallel to the light polarization and nanoparticles settle at saddlepoints where the optical binding force is largely zero. Since the presence and strength of Brownian forces influence which state is formed, we reconsider the role that surfaces have—not only in relation to charge transfer but also heat transfer.

The cooperative phenomena stemming from the radiation field-mediated coupling between individual quantum emitters are presently attracting broad interest for applications related to on-chip photonic quantum memories and long-range entanglement. Common to these applications is the generation of electro-magnetic modes over macroscopic distances. Much research, however, is still needed before such systems can be deployed in the form of practical devices, starting with the investigation of alternate physical platforms. Quantum emitters in two-dimensional (2D) systems provide an intriguing route because these materials can be adapted to arbitrarily shaped substrates to form hybrid systems wherein emitters are near-field-coupled to suitable optical modes. Here, we report a scalable coupling method allowing color center ensembles in a van der Waals material (hexagonal boron nitride) to couple to a delocalized high-quality plasmonic surface lattice resonance. This type of architecture is promising for photonic applications, especially given the ability of the hexagonal boron nitride emitters to operate as single-photon sources at room temperature.

We demonstrate coupling of hBN defect emission to Si3N4 microdisk cavities and high-Q plasmonic surface lattice resonances by exploiting the topography of the photonic elements to engineer strain-activated color centers within the element’s field-mode.