Polariton-assisted splitting of broadband emission spectra of strongly coupled organic dye excitons in tunable optical microcavity

Abstract

Resonance interaction between a localized electromagnetic field and excited states in molecules paves the way to control fundamental properties of a matter. In this study, we encapsulated organic molecules with relatively low unoriented dipole moments in the polymer matrix, placed them in tunable optical microcavity and realized, for the first time, controllable modification of the broad photoluminescence (PL) emission of these molecules in strong coupling regime at room temperature. Notably, while in most previous studies it was reported that the single mode dominates in the PL signal (radiation of the so-called branch of the lower polariton), here we report on the observation of two distinct PL peaks, evolution of which has been followed as the microcavity mode is detuned from the excitonic resonance. A significant Rabi splitting estimated from the modified PL spectra was as large as 225 meV. The developed approach can be used both in fundamental research of resonant light-mater coupling and its practical applications in sensing and development of coherent spontaneous emission sources using a combination of carefully designed microcavity with a wide variety of organic molecules.

Polariton-assisted manipulation of energy relaxation pathways: donor–acceptor role reversal in a tuneable microcavity

“…Previously, we have demonstrated the advantages of the developed tuneable microcavity, such as a controllable distance between the mirrors with a nanometre accuracy and a small mode volume, which result in a much higher Rabi splitting energies compared to the standard optical microcavities. 29 In particular, we have demonstrated a strong coupling of the ensemble of Rhodamine 6G molecules with a Rabi splitting as high as 225 meV at room temperature, which has been previously shown only for the case of surface plasmon-polaritons. A drawback of the tuneable setup developed is that we cannot observe strong coupling in the transmission spectra, which can be due to two effects.…”

“…In order to investigate the feasibility of controlling the resonant energy transfer in a donor-acceptor pair of closely located organic dyes, we have employed a tuneable microcavity with a relatively small mode volume previously developed in our group. [29][30][31] Briey, the tuneable microcavity unit was composed of plane and convex (curvature radius, 77.3 mm) mirrors that form an unstable tuneable Fabry-Perot microcavity (Fig. 1a, see the ESI † for details).…”

Enhanced spontaneous emission from two-photon-pumped quantum dots in a porous silicon microcavity

“…Light-matter resonance interaction enables control over spontaneous photoluminescence (PL) emission properties of various luminophores, including organic dyes [1,2], rare-earth ions [3], 2D metal dichalcogenides [4], and fluorescent nanocrystals [5,6]. The socalled "weak" coupling regime makes it possible to change the spectral, spatial, and temporal properties of the luminophore PL emission by varying the local electro-magnetic environment [7].…”

Strong exciton−photon coupling with colloidal quantum dots in a tunable microcavity

“…The tuneable microcavity, used in our experiments, has been described in detail previously. 18,20 Briefly, it consists of two metal mirrors with a reflection of about 87%: convex (curvature radius, 77.3 mm) upper and a flat bottom mirrors, the latter positioned on a piezo stack. The thickness of the aluminium layer of the mirrors was about 35 nm, with a 20-nm protective SiO2 layer.…”

“…The tuneable microcavity was developed previously and has already demonstrated the capacity for achieving high values of coupling strength. 18 The lateral localization of the optical mode and several orders of magnitude lower values of mode volume has been achieved with the use of an upper mirror with a convex surface. 19,20 In this study, we have obtained strong coupling between exciton transition in colloidal QDs and the optical modes of the tuneable microcavity.…”