Browsing by Subject "Plasmonic lasers"

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    Lasing in a Slow Plasmon Moiré Cavity
    (American Chemical Society, 2015) Karademir, E.; Balci, S.; Kocabas, C.; Aydınlı, Atilla
    We report on lasing from dye-based excitons coupled to slow plasmon states inside metallic Moiré cavities. Surface plasmon polaritons (SPPs) inside the cavity were slowed down to a maximum group velocity of 0.3c. Varying the modulation of the Moiré cavity, we tune the output wavelength of the plasmonic laser by varying the fast modulation period of the Moiré cavity. This work opens a new way to study SPP-matter interaction dynamics and plasmonic lasing with Bragg cavity confined slow plasmons.
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    Light matter interaction in plexcitonic crystals and moiré cavities
    (2015-01) Karademir, Ertuğrul
    Surface plasmon polaritons (SPPs) are quanta of electromagnetic excitations at the interface between metal and dielectric media. SPPs with an evanescent tail in the perpendicular direction, thus their properties are sensitive to variations in the optical properties of the dielectrics film. If SPPs are created near excitonic media, coupling between excitons and SPs can be achieved. In this thesis, interaction dynamics of SPP-exciton coupling is investigated. In weak coupling case, properties of SPPs and excitons are perturbed as the enhancement of the optical absorption in excitonic matrices. In the strong coupling, coupled pairs (plexcitons) causes Rabi splitting in SPP dispersion curves. By patterning the metal-dielectric interface with sine profile grating, it is possible to form a band gap on the dispersion curve, width of which can be tuned by the groove depth and SPP-Exciton coupling can be engineered. Using this, a new type of crystal, plexcitonic crystal, is proposed and demonstrated that exhibit directional dependent coupling on square and triangular lattices. Superposing an additional grating on the initial one but with a slight difference in pitch, results in Moir e cavities, in which, slow plasmon modes can be confined. We show that we can directly image these modes using dark field microscopy. Further, the slow cavity mode in contact with an excitonic source, where SPPs are coupled with near field coupling, results in ampliffed light signal. Various Moire cavities are shown to exhibit plasmonic lasing when slow plasmon modes in Ag coated cavities are excited inside a suitable gain medium.