8 Modulations of Electronic States in Plasmonic Strong Coupling …
145
over a wide wavelength range utilizing the coupled plasmonic systems and near-field
enhancement effects promoted the plasmon-induced water oxidation because IQE
values increased responding to the near-field spectra [20].
8.5 Conclusion
We described the spectral properties of LSPR with molecules in the infrared wavelength region. A distinct spectrum modulation could be observed by the electromagnetic interactions between LSPR and molecular/intermolecular vibrational modes.
Excitation spectrum measurements are crucial to distinguish the coupling regimes
between strong and weak couplings, which was confirmed by the strong coupling
system between LSPR and molecular excitonic states. The modal strong coupling
between LSPR and the other optical mode is promising to control the photochemical reaction because it was demonstrated that the modal strong coupling between
LSPR and the waveguide mode enhances the plasmon-induced water oxidation at
the wavelengths of hybrid states. Actually, we have successfully demonstrated the
modal strong coupling between LSPR and the Fabry–Pérot cavity mode promoted
the water-splitting reaction at the wavelengths of hybrid states [21]. The dephasing
time of LSPR can be also controlled by the modal strong coupling between LSPR
and the long-lived optical mode such as a propagating surface plasmon polariton
[22]. Thus, the strong coupling is promising to modulate electronic and transition
states of materials for controlling the photochemical reactions.
Acknowledgements The author is much grateful to Professors H. Misawa, K. Sasaki, T. Oshikiri,
Q. Sun, X. Shi, and K. Imura, Drs. J. Li, H. Yu, and J. Guo for the fruitful discussions, collaborations, and experiments. The present work was supported by JSPS KAKENHI Grant Numbers
JP15H01073, JP17H05245, JP18H05205, JP19H02737, JP19H04667, the Nanotechnology Platform and the Photo-excitonix Project in Hokkaido University.
References
1. Houdré R, Stanley RP, Oesterle U, Ilegems M, Weisbuch C (1993) Room temperature excitonphoton Rabi splitting in a semiconductor microcavity. J Phys IV 3:51–58
2. Dintinger J, Klein S, Bustos F, Barnes WL, Ebbesen TW (2005) Strong coupling between
surface plasmon-polaritons and organic molecules in subwavelength hole arrays. Phys Rev B
71:035424-1-5
3. Hao Y-W, Wang H-Y, Jiang Y, Chen Q-D, Ueno K, Wang W-Q, Misawa H, Sun H-B (2011)
Hybrid states dynamics of gold nanorods/dye J-aggregate under strong coupling. Angew Chem
Int Ed 50:7824–7828
4. Li J, Ueno K, Uehara H, Guo J, Oshikiri T, Misawa H (2016) Dual strong couplings between
TPPS J-aggregates and aluminum plasmonic states. J Phys Chem Lett 7:2786–2791
145
over a wide wavelength range utilizing the coupled plasmonic systems and near-field
enhancement effects promoted the plasmon-induced water oxidation because IQE
values increased responding to the near-field spectra [20].
8.5 Conclusion
We described the spectral properties of LSPR with molecules in the infrared wavelength region. A distinct spectrum modulation could be observed by the electromagnetic interactions between LSPR and molecular/intermolecular vibrational modes.
Excitation spectrum measurements are crucial to distinguish the coupling regimes
between strong and weak couplings, which was confirmed by the strong coupling
system between LSPR and molecular excitonic states. The modal strong coupling
between LSPR and the other optical mode is promising to control the photochemical reaction because it was demonstrated that the modal strong coupling between
LSPR and the waveguide mode enhances the plasmon-induced water oxidation at
the wavelengths of hybrid states. Actually, we have successfully demonstrated the
modal strong coupling between LSPR and the Fabry–Pérot cavity mode promoted
the water-splitting reaction at the wavelengths of hybrid states [21]. The dephasing
time of LSPR can be also controlled by the modal strong coupling between LSPR
and the long-lived optical mode such as a propagating surface plasmon polariton
[22]. Thus, the strong coupling is promising to modulate electronic and transition
states of materials for controlling the photochemical reactions.
Acknowledgements The author is much grateful to Professors H. Misawa, K. Sasaki, T. Oshikiri,
Q. Sun, X. Shi, and K. Imura, Drs. J. Li, H. Yu, and J. Guo for the fruitful discussions, collaborations, and experiments. The present work was supported by JSPS KAKENHI Grant Numbers
JP15H01073, JP17H05245, JP18H05205, JP19H02737, JP19H04667, the Nanotechnology Platform and the Photo-excitonix Project in Hokkaido University.
References
1. Houdré R, Stanley RP, Oesterle U, Ilegems M, Weisbuch C (1993) Room temperature excitonphoton Rabi splitting in a semiconductor microcavity. J Phys IV 3:51–58
2. Dintinger J, Klein S, Bustos F, Barnes WL, Ebbesen TW (2005) Strong coupling between
surface plasmon-polaritons and organic molecules in subwavelength hole arrays. Phys Rev B
71:035424-1-5
3. Hao Y-W, Wang H-Y, Jiang Y, Chen Q-D, Ueno K, Wang W-Q, Misawa H, Sun H-B (2011)
Hybrid states dynamics of gold nanorods/dye J-aggregate under strong coupling. Angew Chem
Int Ed 50:7824–7828
4. Li J, Ueno K, Uehara H, Guo J, Oshikiri T, Misawa H (2016) Dual strong couplings between
TPPS J-aggregates and aluminum plasmonic states. J Phys Chem Lett 7:2786–2791