Spatial coherence of room-temperature monolayer WSe2 exciton-polaritons in a trap

AbstractThe emergence of spatial and temporal coherence of light emitted from solid-state systems is a fundamental phenomenon intrinsically aligned with the control of light-matter coupling. It is canonical for laser oscillation, emerges in the superradiance of collective emitters, and has been investigated in bosonic condensates of thermalized light, as well as exciton-polaritons. Our room temperature experiments show the strong light-matter coupling between microcavity photons and excitons in atomically thin WSe2. We evidence the density-dependent expansion of spatial and temporal coherence of the emitted light from the spatially confined system ground-state, which is accompanied by a threshold-like response of the emitted light intensity. Additionally, valley-physics is manifested in the presence of an external magnetic field, which allows us to manipulate K and K’ polaritons via the valley-Zeeman-effect. Our findings validate the potential of atomically thin crystals as versatile components of coherent light-sources, and in valleytronic applications at room temperature.

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Optical switching of topological phase in a perovskite polariton lattice

Science Advances ◽

10.1126/sciadv.abf8049 ◽

2021 ◽

Vol 7 (21) ◽

pp. eabf8049

Author(s):

Rui Su ◽

Sanjib Ghosh ◽

Timothy C. H. Liew ◽

Qihua Xiong

Keyword(s):

Optical Switching ◽

Room Temperature ◽

Optical Pumping ◽

Optical Nonlinearity ◽

Edge States ◽

Ambient Conditions ◽

Strong Light ◽

Exciton Polaritons ◽

Matter Interaction ◽

Light Matter Interaction

Strong light-matter interaction enriches topological photonics by dressing light with matter, which provides the possibility to realize active nonlinear topological devices with immunity to defects. Topological exciton polaritons—half-light, half-matter quasiparticles with giant optical nonlinearity—represent a unique platform for active topological photonics. Previous demonstrations of exciton polariton topological insulators demand cryogenic temperatures, and their topological properties are usually fixed. Here, we experimentally demonstrate a room temperature exciton polariton topological insulator in a perovskite zigzag lattice. Polarization serves as a degree of freedom to switch between distinct topological phases, and the topologically nontrivial polariton edge states persist in the presence of onsite energy perturbations, showing strong immunity to disorder. We further demonstrate exciton polariton condensation into the topological edge states under optical pumping. These results provide an ideal platform for realizing active topological polaritonic devices working at ambient conditions, which can find important applications in topological lasers, optical modulation, and switching.

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Microcavity-Like Exciton-Polaritons can be the Primary Photoexcitation in Bare Organic Semiconductors

10.21203/rs.3.rs-361585/v1 ◽

2021 ◽

Author(s):

Akshay Rao ◽

Raj Pandya ◽

Richard Chen ◽

Qifei Gu ◽

Jooyoug Sung ◽

...

Keyword(s):

Organic Semiconductors ◽

Room Temperature ◽

External Cavity ◽

Materials Chemistry ◽

Strong Light ◽

Organic Systems ◽

Reflectivity Spectra ◽

Wide Range ◽

Exciton Polaritons ◽

Photonic States

Abstract Exciton-polaritons (EPs) are quasiparticles formed by the hybridization of excitons with light modes. As organic semiconductors sustain stable excitons at room-temperature, these materials are being actively studied for room temperature polaritonic devices1–3. This is typically in the form of cavity-based systems, where molecules are confined between metallic or dielectric mirrors 4–6 or in a plasmonic gap 7,8. In such systems strong light-matter coupling gives rise to polariton splittings on the order of 200 to 300 meV 6. A wide range of phenomena have been demonstrated in cavity-polariton systems including super-fluidity9, precisely controlled chemical reactions10 and long-range energy propagation11. Here, using a range of chemically diverse model organic systems we show that interactions between excitons and moderately confined photonic states within the (thin) film can lead to the formation of EPs, with a defined lifetime, even in the absence of external cavities. We demonstrate the presence of EPs via angular dependent splittings in reflectivity spectra on the order of 30 meV and collective emission from ~5 ×107 coupled molecules. Additionally, we show that at room temperature these EPs can transport energy up to ~270 nm at velocities of ~5 ×106 m s-1. This propagation velocity and distance is sensitive to, and can be tuned by, the refractive index of the external environment. However, although sensitive to the nanoscale morphology the formation of the exciton-polariton states is a general phenomenon, independent of underlying materials chemistry, with the principal material requirements being a high oscillator strength per unit volume and low disorder. These results and design rules will enable the harnessing of EP effects for a new application in optoelectronics, light harvesting 9,12,13 and cavity controlled chemistry without the limiting requirement of an external cavity.

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Room temperature strong light-matter coupling in three dimensional terahertz meta-atoms

Applied Physics Letters ◽

10.1063/1.4943167 ◽

2016 ◽

Vol 108 (10) ◽

pp. 101101 ◽

Cited By ~ 8

Author(s):

B. Paulillo ◽

J.-M. Manceau ◽

L. H. Li ◽

A. G. Davies ◽

E. H. Linfield ◽

...

Keyword(s):

Room Temperature ◽

Three Dimensional ◽

Strong Light ◽

Matter Coupling

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Room temperature Strong coupling in low finesse GaN microcavities

MRS Proceedings ◽

10.1557/proc-0892-ff20-04 ◽

2005 ◽

Vol 892 ◽

Author(s):

Ian Sellers ◽

Fabrice Semond ◽

Mathieu Leroux ◽

Jean Massies ◽

Pierre Disseix ◽

...

Keyword(s):

Quality Factor ◽

Strong Coupling ◽

Transfer Matrix ◽

Room Temperature ◽

Experimental Results ◽

Strong Light ◽

Matter Coupling ◽

Bulk Gan ◽

Angle Dependent Reflectivity

AbstractWe present experimental results demonstrating strong-light matter coupling at low and room temperature in bulk GaN microcavities. Angle dependent reflectivity measurements demonstrate strong-coupling with a Rabi-energy of 50meV at room temperature which is well reproduced with transfer matrix simulations. The absence of strong coupling in the photoluminescence is attributed to the low finesse of the microcavity (Q=60) and is confirmed by simulations which indicate a quality factor of 90 is required to observe strong-coupling in the emission.

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Strong Light-Matter Coupling in GaN-Based Microcavities Grown on Silicon Substrates

MRS Proceedings ◽

10.1557/proc-1068-c05-06 ◽

2008 ◽

Vol 1068 ◽

Author(s):

Fabrice Semond ◽

Ian Roberts Sellers ◽

Nadège Ollier ◽

Franck Natali ◽

Declan Byrne ◽

...

Keyword(s):

Silicon Substrate ◽

Room Temperature ◽

Silicon Substrates ◽

Strong Light ◽

Matter Coupling

ABSTRACTWe present an overview of our work concerning the fabrication of GaN-based microcavities grown on silicon substrates dedicated to the observation of the strong light-matter coupling regime. In the view of recent promising results in the field, prospects regarding the improvement of heterostructures in order to observe room temperature polariton lasing from a GaN-based microcavity grown on a silicon substrate will be discussed.

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Ultrafast-nonlinear ultraviolet pulse modulation in an AlInGaN polariton waveguide operating up to room temperature

Nature Communications ◽

10.1038/s41467-021-23635-6 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

D. M. Di Paola ◽

P. M. Walker ◽

R. P. A. Emmanuele ◽

A. V. Yulin ◽

J. Ciers ◽

...

Keyword(s):

Refractive Index ◽

Room Temperature ◽

Light Sources ◽

Optical Pulses ◽

Pulse Modulation ◽

Nonlinear Materials ◽

Exciton Polaritons ◽

Nonlinear Modulation ◽

On Chip ◽

New Generation

AbstractUltrafast nonlinear photonics enables a host of applications in advanced on-chip spectroscopy and information processing. These rely on a strong intensity dependent (nonlinear) refractive index capable of modulating optical pulses on sub-picosecond timescales and on length scales suitable for integrated photonics. Currently there is no platform that can provide this for the UV spectral range where broadband spectra generated by nonlinear modulation can pave the way to new on-chip ultrafast (bio-) chemical spectroscopy devices. We demonstrate the giant nonlinearity of UV hybrid light-matter states (exciton-polaritons) up to room temperature in an AlInGaN waveguide. We experimentally measure ultrafast nonlinear spectral broadening of UV pulses in a compact 100 μm long device and deduce a nonlinearity 1000 times that in common UV nonlinear materials and comparable to non-UV polariton devices. Our demonstration promises to underpin a new generation of integrated UV nonlinear light sources for advanced spectroscopy and measurement.

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