Browsing by Author "Gokbulut, Belkis"

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Enhanced light-matter interaction in a hybrid photonic-plasmonic cavity
(Springer Heidelberg, 2021) Gokbulut, Belkis; Inanc, Arda; Topcu, Gokhan; Ozcelik, Serdar; Demir, Mustafa M.; Inci, M. Naci
Strongly concentrated optical fields around a metal nanoparticle in the close vicinity of a dipole noticeably facilitate dramatic changes in the localized density of states due to hybrid photonic-plasmonic mode couplings as compared to that of the pure cavity mode fields. Significant variations of the field intensity in the presence of the metal nanoparticle elucidate enhanced light-matter interaction in a hybrid structure. The enhancement factor of the light-matter interaction is studied through the single-atom cooperativity parameter, which is directly proportional to the ratio of the fluorescence lifetimes of the off-resonant and on-resonant emission. A compact and cost-effective hybrid device, which includes a microfiber cavity, supporting whispering gallery modes, and a well-defined solid nanostructure, consisting of a gold nanoparticle core, overcoated by a silica shell, and decorated with CdS/CdSe quantum dots, is demonstrated to offer an outstanding potential for the enhancement of light-matter interaction. Surface plasmons of a gold nanoparticle, placed inside a hollow cylindrical nanostructure at the surface of a microfiber, are activated upon excitation of the dipoles of the quantum emitters, which are on-resonance with the whispering gallery mode. Time-resolved experiments demonstrate that the single-atom cooperativity parameter of the quantum dots is enhanced by a factor of about 4.8 in the presence of the gold nanoparticle being simultaneously in strong interaction with the cavity mode field and the metal nanoparticle's surface plasmons.
Enhanced light-matter interaction in a hybrid photonic-plasmonic cavity (vol 127, 907, 2021)
(Springer Heidelberg, 2022) Gokbulut, Belkis; Inanc, Arda; Topcu, Gokhan; Ozcelik, Serdar; Demir, Mustafa M.; Inci, M. Naci
[No Abstract Available]
Enhanced Spontaneous Emission Rate in a Low-Q Hybrid Photonic-Plasmonic Nanoresonator
(Amer Chemical Soc, 2019) Gokbulut, Belkis; Inanc, Arda; Topcu, Gokhan; Unluturk, Secil S.; Ozcelik, Serdar; Demir, Mustafa M.; Inci, M. Naci
In this paper, CdTe quantum dots (QDs)-doped single electrospun polymer nanofibers are partially coated with gold nanoparticles to form distinct hybrid photonic-plasmonic nanoresonators to investigate the critical role of the cavity-confined hybrid mode on the modification of the spontaneous emission dynamics of the fluorescent emitters in low-Q photonic cavities. A total enhancement factor of 11.2 is measured via a time-resolved experimental technique, which shows that there is an increase of about three times in the spontaneous emission rate for the QDs-doped gold nanoparticle-decorated nanofibers as they are compared with those uncoated ones. The physical mechanism affecting the spontaneous emission rate of the encapsulated QDs in such a hybrid photonic-plasmonic nanoresonator is explained to be due to regeneration of the mode field in the nanofiber cavity upon the interaction of the dipoles with the surface plasmons of distinctive gold nanoparticles that surround the outer surface of the nanofiber.
Hybrid photonic-plasmonic mode-coupling induced enhancement of the spontaneous emission rate of CdS/CdSe quantum emitters
(Elsevier, 2022) Gokbulut, Belkis; Inanc, Arda; Topcu, Gokhan; Ozcelik, Serdar; Demir, Mustafa M.; Inci, M. Naci
In this paper, a hybrid photonic-plasmonic resonator, which comprises an electrospun polymer fiber with a micrometer diameter and a core/shell nanostructure with a gold nanoparticle core, is constructed to investigate the dynamics of the coupled spontaneous emission of CdS/CdSe quantum dots (QDs). The gold nanoparticle core; covered with a silica shell, anchored with individual CdS/CdSe QDs, is placed inside a hollow cylindrical nanocavity formed on the surface of the microfiber to enable integration of the optical mode with the plasmonic effect, which is induced by the localized surface plasmons of the metal nanoparticle being present in the vicinity of the dipoles. The spontaneous emission rate of the QDs, coupled into the hybrid photonic-plasmonic mode, is measured to enhance by a factor of 23 via a time-resolved experimental technique. This result suggests that the regeneration of the optical mode-field inside the photonic-plasmonic resonator through the interaction of the dipoles with the localized surface plasmons of a metal nanoparticle strongly enhances the density of the elec-tromagnetic states of the quantum emitters to facilitate an enhanced spontaneous emission within the host medium of the proposed polymer based-photonic structure.
Plasmon-induced spectral tunability of Perovskite nanowires
(Elsevier, 2021) Gokbulut, Belkis; Topcu, Gokhan; Demir, Mustafa M.; Inci, M. Naci
In this paper, plasmon-assisted spectral tunability in random media, composed of Perovskite (CsPbBr3) nanowires surrounded by Au nanoparticle clusters in polystyrene matrix, is achieved. The interaction between the surface plasmons and the quantum sources is observed to generate photoluminescence from the higher excited state energy levels of the excited semiconductor nanowires, which results in a blueshifted fluorescence emission of 50 nm. The localized surface plasmon properties are also determined to be tuned by plasmonic pumping of the quantum sources at different resonant frequencies. Thus, the first observation of the tunable blueshifted fluorescence emission of the semiconductor nanocrystals surrounded by plasmonic nanoparticle aggregates is achieved. The dramatic changes in the spectral profiles of the fluorescent nanowires are attributed to be due to the fast dynamics surface enhanced fluorescence mechanism.