Cooperative energy transfer

M. Altarelli, David L. Dexter

V. M. Akulin, Yu. N. Belousov

Sergey K. Sekatskii, Konstantin K. Pukhov

Cooperative fluorescence resonance energy transfer effect is experimentally demonstrated for a few crystals doped with rare-earth ions. We show that, at the liquid helium temperatures in similar crystals, coherent cooperative fluorescence resonance energy transfer, as well as an inverse coherent up-conversion process, could be observed, and briefly discuss possible applications of these effects.

Tasoltan T. Basiev, Maxim E. Doroshenko, В. В. Осико

Summary form only given. We report on a new nonlinear optical phenomenon in LaCeF/sub 3/:Nd crystals of cooperative energy transfer-cooperative cross-relaxation, that is the energy transfer from single donor ion simultaneously to the pair (or more) ions, acting as nonlinear cooperative acceptor. The dependence of fluorescence intensity and decay rate at the kinetic stage of the process here can not be described by linear dependence on acceptor's concentration and becomes essentially nonlinear.

Philipp O. J. Scherer, Sighart F. Fischer

Tigran V. Shahbazyan

We develop a theory of cooperative emission mediated by cooperative energy transfer (CET) from an ensemble of quantum emitters (QEs) to plasmonic antenna at a rate equal to the sum of individual QE-plasmon energy transfer rates. If the antenna radiation efficiency is sufficiently high, the transferred energy is radiated away at approximately the same cooperative rate that scales with the ensemble size. We derive explicit expressions, in terms of local fields, for cooperative Purcell factor and enhancement factor for power spectrum valid for plasmonic structures of any shape with characteristic sizes smaller than the radiation wavelength. The radiated power spectrum retains the plasmon resonance lineshape with overall amplitude scaling with the ensemble size. If QEs are located in a region with nearly constant plasmon local density of states (LDOS), e.g., inside a plasmonic nanocavity, we demonstrate that the CET rate scales linearly with the number of excited QEs, consistent with the experiment, and can be tuned in a wide range by varying the excitation power. For QEs distributed in an extended region saturating the plasmon mode volume, we show that the cooperative Purcell factor has universal form independent of the system size. The CET mechanism incorporates the plasmon LDOS enhancement as well, giving rise to possibilities of controlling the emission rate beyond field enhancement limits.