The exciton–polariton (EP), a half-light and half-matter quasiparticle, is potentially an important element for future photonic and quantum technologies1,2,3,4. It provides both strong light–matter interactions and long-distance propagation that is necessary for applications associated with energy or information transfer. Recently, strongly coupled cavity EPs at room temperature have been demonstrated in van der Waals (vdW) materials due to their strongly bound excitons5,6,7,8,9. Here, we report a nano-optical imaging study of waveguide EPs in MoSe2, a prototypical vdW semiconductor. The measured propagation length of the EPs is sensitive to the excitation photon energy and reaches over 12 µm. The polariton wavelength can be conveniently altered from 600 nm down to 300 nm by controlling the waveguide thickness. Furthermore, we found an intriguing back-bending polariton dispersion close to the exciton resonance. The observed EPs in vdW semiconductors could be useful in future nanophotonic circuits operating in the near-infrared to visible spectral regions.
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Weisbuch, C. et al. Observation of the coupled exciton–photon mode splitting in a semiconductor quantum microcavity. Phys. Rev. Lett. 69, 3314–3317 (1992).
Gibbs, H. M., Khitrova, G. & Koch, S. W. Exciton–polariton light–semiconductor coupling effects. Nat. Photon. 5, 275–282 (2011).
Tassone, F., Bassani, F. & Andreani, L. C. Quantum-well reflectivity and exciton–polariton dispersion. Phys. Rev. B 45, 6023–6030 (1992).
Deng, H., Haug, H. & Yamamoto, Y. Exciton–polariton Bose–Einstein condensation. Rev. Mod. Phys. 82, 1489–1537 (2010).
Liu, X. et al. Strong light–matter coupling in two-dimensional atomic crystals. Nat. Photon. 9, 30–34 (2015).
Dufferwiel, S. et al. Exciton–polaritons in van der Waals heterostructures embedded in tunable microcavities. Nat. Commun. 6, 8579 (2015).
Lundt, N. et al. Room-temperature Tamm-plasmon exciton–polaritons with a WSe2 monolayer. Nat. Commun. 7, 13328 (2016).
Flatten, L. C. et al. Room-temperature exciton polaritons with two-dimensional WS2 . Sci. Rep. 6, 33134 (2016).
Wang, Q. et al. Direct observation of strong light–exciton coupling in thin WS2 flakes. Opt. Express 24, 7151–7157 (2016).
Basov, D. N., Fogler, M. M. & García de Abajo, F. J. Polaritons in van der Waals materials. Science 354, 195 (2016).
Low, T. et al. Polaritons in layered two-dimensional materials. Nat. Mater. 16, 182–194 (2017).
Ju, L. et al. Graphene plasmonics for tunable terahertz metamaterials. Nat. Nanotech. 6, 630–634 (2011).
Fei, Z. et al. Gate-tuning of graphene plasmons revealed by infrared nano-imaging. Nature 487, 82–85 (2012).
Chen, J. et al. Optical nano-imaging of gate-tunable graphene plasmons. Nature 487, 77–81 (2012).
Woessner, G. et al. Highly confined low-loss plasmons in graphene–boron nitride heterostructures. Nat. Mater. 14, 421–425 (2015).
Dai, S. et al. Tunable phonon polaritons in atomically thin van der Waals crystals of boron nitride. Science 343, 1125–1129 (2014).
Li, P. et al. Hyperbolic phonon–polaritons in boron nitride for near-field optical imaging and focusing. Nat. Commun. 6, 7507 (2015).
Yoxall, E. et al. Direct observation of ultraslow hyperbolic polariton propagation with negative phase velocity. Nat. Photon. 9, 674–678 (2015).
Splendiani, A. et al. Emerging photoluminescence in monolayer MoS2 . Nano Lett. 10, 1271–1275 (2010).
Mak, K. F., Lee, C., Hone, J., Shan, J. & Heinz, T. F. Atomically thin MoS2: a new direct-gap semiconductor. Phys. Rev. Lett. 105, 136805 (2010).
Radisavljevic, B., Radenovic, A., Brivio, J., Giacometti, V. & Kis, A. Single-layer MoS2 transistors. Nat. Nanotech. 6, 147–150 (2011).
Wang, Q. H., Kalantar-Zadeh, K., Kis, A., Coleman, J. N. & Strano, M. S. Electronic and optoelectronics of two-dimensional transition metal dichalcogenides. Nat. Nanotech. 7, 699–712 (2012).
Fei, Z. et al. Nano-optical imaging of WSe2 waveguide modes revealing light–exciton interactions. Phys. Rev. B 94, 081402(R) (2016).
Katsuyama, T. & Ogawa, K. Excitonic polaritons in quantum-confined systems and applications to optoelectronic devices. J. Appl. Phys. 75, 7607–7625 (1994).
van Vugt, L. K. et al. Exciton polaritons confined in a ZnO nanowire cavity. Phys. Rev. Lett. 97, 147401 (2006).
Takazawa, K. et al. Fraction of a millimeter propagation of exciton polaritons in photoexcited nanofibers of organic dye. Phys. Rev. Lett. 105, 067401 (2010).
Liscidini, M. et al. Guided Bloch surface wave polaritons. Appl. Phys. Lett. 98, 121118 (2011).
Ellenbogen, T., Steinvurzel, P. & Crozier, K. B. Strong coupling between excitons in J-aggregates and waveguide modes in thin polymer films. Appl. Phys. Lett. 98, 261103 (2011).
Arakawa, E. T., Williams, M. W., Hamm, R. N. & Ritchie, R. H. Effect of damping on surface plasmon dispersion. Phys. Rev. Lett. 31, 1127–1129 (1973).
Schuller, E., Falge, H. J. & Borstel, G. Dispersion curves of surface phonon–polaritons with backbending. Phys. Lett. A 54, 317–318 (1975).
F.H., Y.L. and Z.F. acknowledge start-up support from Iowa State University and Ames Laboratory. The nano-optical imaging set-up was partially supported by the W. M. Keck foundation. The work at the University of Washington was supported by the US Department of Energy, Basic Energy Sciences, Materials Sciences and Engineering Division (DE-SC0008145 and SC0012509). The work at Oak Ridge National Laboratory (J.Y. and D.G.M.) was supported by the US Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division.
The authors declare no competing financial interests.
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Hu, F., Luan, Y., Scott, M. et al. Imaging exciton–polariton transport in MoSe2 waveguides. Nature Photon 11, 356–360 (2017). https://doi.org/10.1038/nphoton.2017.65
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