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Abstract Deterministic positioning single site-controlled high symmetric InGaAs quantum dots (QDs) in (111)B-oriented GaAs photonic crystal cavities with nanometer-scale accuracy provides an idea component for building integrated quantum photonic circuits. However, it has been a long-standing challenge of improving cavityQ-factors in such systems. Here, by optimizing the trade-off between the cavity loss and QD spectral quality, we demonstrate our site-controlled QD-nanocavity system operating in the intermediate coupling regime mediated by phonon scattering, with the dynamic coexistence of strong and weak coupling. The cavity-exciton detuning-dependent micro-photoluminescence spectrum reveals concurrence of a trend of exciton-polariton mode avoided crossing, as a signature of Rabi doublet of the strongly coupled system. Meanwhile, a trend of keeping constant or slight blue shift of coupled exciton–cavity mode(CM) energy across zero-detuning is ascribed to the formation of collective states mediated by phonon-assisted coupling, and their rare partial out-of-synchronization linewidth-narrowing is linked to their coexisting strong-weak coupling regime. We further reveal the pump power-dependent anti-bunching photon statistical dynamics of this coexisting strong-weak coupled system and the optical features of strongly confined exciton-polaritons, and dark-exciton-like states. These observations demonstrate the potential capabilities of site-controlled QD-cavity systems as deterministic quantum nodes for on-chip quantum information processing and provide guidelines for future device optimization for achieving the strong coupling regime.
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Continuously Tuning Strong Exciton–Photon Coupling via Molecular Orientation in Organic Microcavities
Abstract Exciton‐polaritons in organic microcavities are applied in devices including lasers, light‐emitting devices, and photodetectors, as well as in structures capable of tuning exciton kinetics and energy transfer. To enable a broader tailoring of polariton properties, it is important to develop means to better control molecular orientation and tune the intensity of the exciton–photon interaction. Vapor‐processed, glassy organic thin films are previously shown to have tunable molecular orientation as evidenced by phenomena including birefringence and transition dipole moment (TDM) alignment. Here, this tunability in TDM orientation with thin film processing conditions is exploited to continuously vary the interaction between the exciton and confined cavity photon mode. By embedding a thin film of 4,4′‐bis[(N‐carbazole)styryl]biphenyl (BSB‐Cz) in a metal‐reflector microcavity, ultrastrong coupling and hybridization of multiple electronic transitions of BSB‐Cz are demonstrated with a common cavity mode. Increasing the temperature during BSB‐Cz deposition tunes the TDM orientation from predominantly in‐plane to random to slightly vertical. This leads to a corresponding ≈30% variation in the associated Rabi splitting, consistent with theoretical predictions. This work demonstrates a means to continuously tune coupling strength from a materials perspective while also providing a handle to tune orientation disorder in thin film.
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- Award ID(s):
- 2011401
- PAR ID:
- 10582375
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Optical Materials
- Volume:
- 13
- Issue:
- 12
- ISSN:
- 2195-1071
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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