Molecular Monolayer Strong Coupling in Dielectric Soft Microcavities (article)

This is the final version. Available on open access from the American Chemical Society via the DOI in this recordThe dataset associated with this article is available in ORE: https://doi.org/10.24378/exe.2823We report strong coupling of a monolayer of J-aggregated dye molecules to the whispering gallery modes of a dielectric microsphere at room temperature. We systematically studied the evolution of strong coupling as the number of layers of dye molecules was increased and found the Rabi splitting to rise from 56 meV for a single layer to 94 meV for four layers of dye molecules. We compare our experimental results with two-dimensional (2D) numerical simulations and a simple coupled oscillator model, finding good agreement. We anticipate that these results will act as a stepping stone for integrating molecule-cavity strong coupling in a microfluidic environment since microspheres can be easily trapped and manipulated in such an environment and provide open access cavities.European Research Council (ERC

Polariton assisted photoemission from a layered molecular material: Role of vibrational states and molecular absorption (article)

This is the final version. Available on open access from the Royal Society of Chemistry via the DOI in this recordThe dataset associated with this article is available in ORE at: https://doi.org/10.24378/exe.3483The way molecules absorb, transfer, and emit light can be modified by coupling them to optical cavities. The extent of the modification is often defined by the cavity–molecule coupling strength, which depends on the number of coupled molecules. We experimentally and numerically study the evolution of photoemission from a thin layered J-aggregated molecular material strongly coupled to a Fabry–Perot microcavity as a function of the number of coupled layers. We unveil an important difference between the strong coupling signatures obtained from reflection spectroscopy and from polariton assisted photoluminescence. We also study the effect of the vibrational modes supported by the molecular material on the polariton assisted emission both for a focused laser beam and for normally incident excitation, for two different excitation wavelengths: a laser in resonance with the lower polariton branch, and a laser not in resonance. We found that Raman scattered photons appear to play an important role in populating the lower polariton branch, especially when the system was excited with a laser in resonance with the lower polariton branch. We also found that the polariton assisted photoemission depends on the extent of modification of the molecular absorption induced by the molecule–cavity coupling.Leverhulme TrustEuropean Research Council (ERC

Role of Symmetry Breaking in Observing Strong Molecule-Cavity Coupling Using Dielectric Microspheres

This is the final version. Available from the American Chemical Society via the DOI in this record. The emergence of dielectric open optical cavities has opened a new research avenue in nanophotonics. In particular, dielectric microspheres support a rich set of cavity modes with varying spectral characteristics, making them an ideal platform to study molecule-cavity interactions. The symmetry of the structure plays a critical role in the outcoupling of these modes and, hence, the perceived molecule-cavity coupling strength. Here, we experimentally and theoretically study molecule-cavity coupling mediated by the Mie scattering modes of a dielectric microsphere placed on a glass substrate and excited with far-field illumination, from which we collect scattering signatures both in the air and glass sides. Glass-side collection reveals clear signatures of strong molecule-cavity coupling (coupling strength 2g = 74 meV), in contrast to the air-side scattering signal. Rigorous electromagnetic modeling allows us to understand molecule-cavity coupling and unravel the role played by the spatial mode profile in the observed coupling strength.European Research Council (ERC)European Research Council (ERC)Spanish MICINNSpanish MICINNCatalan CERCA ProgramFundaciós Cellex and Mir-Pui

Strong Coupling of Multimolecular Species to Soft Microcavities (article)

This is the final version. Available on open access from the American Chemical Society via the DOI in this recordThe dataset associated with this article is available in ORE at: https://doi.org/10.24378/exe.3763Can we couple multiple molecular species to soft-cavities? The answer to this question has relevance in designing open cavities for polaritonic chemistry applications. Due to the differences in adhesiveness it is difficult to couple multiple molecular species to open cavities in a controlled and precise manner. In this letter, we discuss the procedure to coat multiple dyes, TDBC and S2275, using a layer-by-layer deposition technique onto a dielectric microsphere so as to facilitate the multi molecule coupling. We observed the formation of a middle polariton branch due to the inter-molecular mixing facilitated by the whispering gallery modes. The coupling strength,2g, of the TDBC molecules were found to be 98 meV while that of S2275 molecules was 78 meV. The coupling strength was found to be greater than the cavity linewidth and the molecular absorption linewidth showing the system is in the strong coupling regime.European Research Council (ERC

Molecular Monolayer Strong Coupling in Dielectric Soft Microcavities (dataset)

Experimental and numerical simulation data used in the Vasista and Barnes (2020) article "Molecular Monolayer Strong Coupling in Dielectric Soft Microcavities" published in Nano Letters.The article associated with this dataset is available in ORE at: http://hdl.handle.net/10871/126720We report strong coupling of a monolayer of J-aggregated dye molecules to the whispering gallery modes of a dielectric microsphere at room temperature. We systematically studied the evolution of strong coupling as the number of layers of dye molecules was increased and found the Rabi splitting to rise from 56 meV for a single layer to 94 meV for four layers of dye molecules. We compare our experimental results with two-dimensional (2D) numerical simulations and a simple coupled oscillator model, finding good agreement. We anticipate that these results will act as a stepping stone for integrating molecule-cavity strong coupling in a microfluidic environment since microspheres can be easily trapped and manipulated in such an environment and provide open access cavities.European Research Council (ERC

Strong Coupling of Multimolecular Species to Soft Microcavities (dataset)

Raw data for figures as text file.The article associated with this dataset is available in ORE at: http://hdl.handle.net/10871/128285This is the dataset used for the Vasista and Barnes (2022) article "Strong Coupling of Multimolecular Species to Soft Microcavities" published in the Journal of Physical Chemistry Letter.European Research Council (ERC

Polariton assisted photoemission from a layered molecular material: Role of vibrational states and molecular absorption (dataset)

This is the dataset used for the Vasista et al. (2021) article "Polariton assisted photoemission from a layered molecular material: Role of vibrational states and molecular absorption" published in Nanoscale.The article associated with this dataset is available in ORE at: http://hdl.handle.net/10871/126718The way molecules absorb, transfer, and emit light can be modified by coupling them to optical cavities. The extent of the modification is often defined by the cavity-molecule coupling strength, which depends on the number of coupled molecules. We experimentally and numerically study the evolution of photoemission from a thin layered J-aggregated molecular material strongly coupled to a Fabry-Perot microcavity as a function of the number of coupled layers. We unveil an important difference between the strong coupling signatures obtained from reflection spectroscopy and from polariton assisted photoluminescence. We also study the effect of the vibrational modes supported by the molecular material on the polariton assisted emission both for a focused laser beam and for normally incident excitation, for two different excitation wavelengths: a laser in resonance with the lower polariton branch, and a laser not in resonance. We found that Raman scattered photons appear to play an important role in populating the lower polariton branch, especially when the system was excited with a laser in resonance with the lower polariton branch. We also found that the polariton assisted photoemission depends on the extent of modification of the molecular absorption induced by the molecule-cavity coupling.Leverhulme TrustEuropean Research Council (ERC