Deep subwavelength plasmonic whispering-gallery-mode cavity

Optics Express (Impact Factor: 3.49). 10/2012; 20(22):24918-24. DOI: 10.1364/OE.20.024918
Source: PubMed


We propose a plasmonic whispering-gallery-mode cavity comprising of a dielectric disk with sub-hundred nanometer thickness sandwiched by two silver disks. By reducing radius and thickness carefully based on the investigated resonant wavelength dependencies, the surface-plasmon-polariton cavity mode with a resonant wavelength of 1550 nm can be confined in a disk with a radius of 88 nm and a thickness of 10 nm, where the physical size of the cavity is 0.000064 λ0 30: free space wavelength). The cavity mode has a deep subwavelength mode volume of 0.010 (λ/2n)3 and a high quality factor of 1900 at 40K, consequently, a large Purcell factor of 1.1 x 105.

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    • "By amplifying the SPP wave instead of pure light, the world's first sub-100 nm laser was demonstrated [14]. Later, a subwavelength WGM plasmonic laser was also achieved by Kwon et al [15] via a similar mechanism. However, to date, there are very few reports focusing on the impact of plasmonic metal nanoparticles on the behavior of lasers, except Ertugrul et al's pioneering work on using resonant Au nanostructures to manipulate a laser diode's output beam shape and far field patterns [18]. "
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    ABSTRACT: Plasmonic noble metal nanodisks with regular (triangular or hexagonal) shapes have been epitaxially formed on ZnO nanorods' (0002) surfaces. The composite material's crystal structures, epitaxial relationships between metal nanodisks, and ZnO host crystals were fully investigated. The effects from metal nanodisks on lasing characteristics of two types of ZnO nanoscale cavities (Fabry-Perot and Whispering Gallery Mode cavity) were studied. The results suggest that metal nanodisks can effectively enhance the lasing performance by lowering the lasing threshold in the ZnO Whispering Gallery Mode nanoplate laser, whereas the Fabry-Perot ZnO nanorods lasers were much less affected by the metal decoration. The plasmonic enhancement mechanism for the ZnO nanoplate cavities was further studied using numerical simulations as well as spatially resolved photoluminescence measurement.
    Full-text · Article · Jul 2014 · Nanotechnology
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    • "WG microtoroid resonator has also been demonstrated recently to attain plasmonic resonance Q value reaching 1000 when coated with metal [21]. On the subwavelength scale, a plasmonic dielectric WG cavity sandwiched between two silver disk has been proposed to attain Q value of 60 at room temperature and reaching 1900 at 40 K [22]. "
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    ABSTRACT: In this paper, we demonstrate a hybrid plasmonic bottle microresonator (PBMR) which supports whispering gallery modes (WGMs) along with surface plasmon waves (SPWs) for high performance optical sensor applications. The BMR was fabricated through "soften-and-compress" technique with a thin gold layer deposited on top of the resonator. A polarization-resolved measurement was set-up in order to fully characterize the fabricated PBMR. Initially, the uncoated BMR with waist diameter of 181 μm, stem diameter of 125 μm and length of 400 μm was fabricated and then gold film was deposited on the surface. Due to surface curvature, the gold film covering half of the BMR had a characteristic meniscus shape and maximum thickness of 30 nm. The meniscus provides appropriately tapered edges which facilitate the adiabatic transformation of BMR WGMs to SPWs and vice versa. This results in low transition losses, which combined with partially-metal-coated resonator, can result in high hybrid-PBMR Q's. The transmission spectra of the hybrid PBMR are dramatically different to the original uncoated BMR. Under TE(TM) excitation, the PBMR showed composite resonances with Q of ~2100(850) and almost identical ~ 3 nm FSR. We have accurately fitted the observed transmission resonances with Lorentzian-shaped curves and showed that the TE and TM excitations are actually composite resonances comprise of two and three partially overlapping resonances with Q's in excess of 2900 and 2500, respectively. To the best of our knowledge these are the highest Qs observed in plasmonic microcavities.
    Full-text · Article · Feb 2014 · Proceedings of SPIE - The International Society for Optical Engineering
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    • "Furthermore, we also show that our designed nanoring laser is the smallest presented to date, where the total footprint of the nanolaser is about 0.038 µm 2 , the physical device volume and the effective mode volume are only about 1.1(λ/2n) 3 and 0.001(λ/2n) 3 , respectively. Smaller passive nanocavity has been proposed before [18] [19]. Nevertheless, the emphasis of our work is the integrated semiconductor plasmonic nanolaser. "
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    ABSTRACT: We present design and analysis of metallic-semiconductor nanoring laser lasing at around 1450 nm wavelength, utilizing a body-of-revolution finite-difference-time-domain (BOR-FDTD) simulation incorporated with a semiclassical multilevel model for semiconductor gain medium and the Drude-Lorentz model for metal, which is developed for efficient simulation of disk/ring plasmonic laser. As compared to other literature, our nanoring laser works in radial mode with resonance cycle, m = 1, which could facilitate potential in-plane out-coupling, and is wafer bonded onto Si platform for potential electronic-photonic integration. The total footprint, the physical device volume, and the effective mode volume of the nanolaser are only about 0.038 mu m(2), 1.1(lambda/2n)(3), and 0.001(lambda/2n)(3), respectively, where n is the average refractive index of the gain medium. To the best of our knowledge, our nanolaser is the smallest reported to date.
    Full-text · Article · May 2013 · IEEE Photonics Technology Letters
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