The condensation of half-light half-matter exciton polaritons in semiconductor optical cavities is a striking example of macroscopic quantum coherence in a solid-state platform. Quantum coherence is possible only when there are strong interactions between the exciton polaritons provided by their excitonic constituents. Rydberg excitons with high principal value exhibit strong dipole–dipole interactions in cold atoms. However, polaritons with the excitonic constituent that is an excited state, namely Rydberg exciton polaritons (REPs), have not yet been experimentally observed. Here, we observe the formation of REPs in a single crystal CsPbBr 3 perovskite cavity without any external fields. These polaritons exhibit strong nonlinear behavior that leads to a coherent polariton condensate with a prominent blue shift. Furthermore, the REPs in CsPbBr 3 are highly anisotropic and have a large extinction ratio, arising from the perovskite’s orthorhombic crystal structure. Our observation not only sheds light on the importance of many-body physics in coherent polariton systems involving higher-order excited states, but also paves the way for exploring these coherent interactions for solid-state quantum optical information processing.
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A Fourier processor for partially coherent fields
We extend conventional coherent Fourier processing techniques to a partially coherent field and modify its spatial coherence using a 4 f system. The coherence is measured by a modified Mach–Zehnder interferometer. Our results corroborate the predictions in [ Opt. Lett. 42 , 4600 ( 2017 ) 10.1364/OL.42.004600 ] and can be extended to a more sophisticated processing of spatial coherence.
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- Award ID(s):
- 1659539
- PAR ID:
- 10348777
- Date Published:
- Journal Name:
- OSA Continuum
- Volume:
- 3
- Issue:
- 10
- ISSN:
- 2578-7519
- Page Range / eLocation ID:
- 2843
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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