科研成果

2017
Coupled-resonator-induced plasmonic bandgaps
Wang, Y., Sun, C., Gong, Q. & Chen*, J. Coupled-resonator-induced plasmonic bandgaps. Optics Letters 42, 4235-4238 (2017). 访问链接
Plasmonic polarization-rotating emitters with metallic nano-groove antennas
Sun, C., Li, H., Gong, Q. & Chen, J.* Plasmonic polarization-rotating emitters with metallic nano-groove antennas. Advanced Optical Materials (2017).
An on-chip polarization splitter based on the radiation loss in the bending hybrid plasmonic waveguide structure
Sun, C., et al. An on-chip polarization splitter based on the radiation loss in the bending hybrid plasmonic waveguide structure. Applied Physics Letters 111, 101105 (2017). 访问链接Abstract
Polarization beam splitters (PBSs) are one of the key components in the integrated photonic circuits. To increase the integration density, various complex hybrid plasmonic structures have been numerically designed to shrink the footprints of the PBSs. Here, to decrease the complexity of the small hybrid structures and the difficulty of the hybrid micro-nano fabrications, the radiation losses are utilized to experimentally demonstrate an ultra-small, broadband, and efficient PBS in a simple bending hybrid plasmonic waveguide structure. The hybrid plasmonic waveguide comprising a dielectric strip on the metal surface supports both the transverse-magnetic (TM) and transverse-electric (TE) waveguide modes. Because of the different field confinements, the TE waveguide mode has larger radiation loss than the TM waveguide mode in the bending hybrid strip waveguide. Based on the different radiation losses, the two incident waveguide modes of orthogonal polarization states are efficiently split in the proposed structure with a footprint of only about 2.2 × 2.2 μm2 on chips. Since there is no resonance or interference in the splitting process, the operation bandwidth is as broad as Δλ = 70 nm. Moreover, the utilization of the strongly confined waveguide modes instead of the bulk free-space light (with the spot size of at least a few wavelengths) as the incident source considerably increases the coupling efficiency, resulting in a low insertion loss of <3 dB.
Room-Temperature Planar Lasers Based on Water-Dripping Microplates of Colloidal Quantum Dots
Rong, K., Sun, C., Shi, K., Gong, Q. & Chen, J.* Room-Temperature Planar Lasers Based on Water-Dripping Microplates of Colloidal Quantum Dots. ACS Photonics 4, 1776–1784 (2017). 访问链接
Self-reference plasmonic sensors based on double Fano resonances
Wang, Y., Sun, C., Li, H., Gong, Q. & Chen, J.* Self-reference plasmonic sensors based on double Fano resonances. Nanoscale 9, 11085-11092 (2017). 访问链接Abstract
High-sensitivity plasmonic refractive index sensors show great applications in the areas of the biomedical diagnostics, healthcare, food safety, environmental monitoring, homeland security, and chemical reaction. However, the unstable and complicated environments considerably limit their practical applications. By employing the independent double Fano resonances in a simple metallic grating, we experimentally demonstrated a self-reference plasmonic sensor, which significantly reduces the error contributions of the light intensity fluctuations in the long-distance propagation and local temperature variations at the metallic grating, and the detection accuracy is guaranteed. The numerical simulation shows that the two Fano resonances have different originations and are independent with each other. As a result, the left Fano resonance is quite sensitive to the refractive index variations above the metal surface, while the right Fano resonance is insensitive to that. Experimentally, a high figure of merit (FOM) of 31 RIU-1 and FOM* of 860 RIU-1 are realized by using the left Fano resonance. More importantly, by using the right Fano resonance as a reference signal, the influence of the light intensity fluctuations and local temperature variations are monitored and eliminated in the experiment. This simple self-reference plasmonic sensor based on the double Fano resonances may find important applications in high-sensitive and accurate sensing under the unstable and complicated environments, as well as multi-parameter sensing.
Multimode metallic double-strip waveguides for polarization manipulation
Gan, F., et al. Multimode metallic double-strip waveguides for polarization manipulation. Advanced Materials Technologies 1600248 (2017). 访问链接
Sharp phase variations from the plasmon mode causing the Rabi-analogue splitting
Wang, Y., et al. Sharp phase variations from the plasmon mode causing the Rabi-analogue splitting. Nanophotonics 6, 1101–1107 (2017). 访问链接
Widely Tuning Surface Plasmon Polaritons with Laser-Induced Bubbles
Gan, F., et al. Widely Tuning Surface Plasmon Polaritons with Laser-Induced Bubbles. Advanced Optical Materials 5, 1600545 (2017). 访问链接
2016
Y, B., et al. Efficient Unidirectional Launching of Surface Plasmons by Multi-Groove Structures. Plasmonics doi:10.1007/s11468-016-0402-3 (2016). 访问链接
Wang, B., et al. Visible-frequency dielectric metasurfaces for multiwavelength achromatic and highly dispersive holograms. Nano Letters 16, 5235-5240 (2016). 访问链接
Controlling Surface-plasmon-polariton Launching with Hot Spot Cylindrical Waves in a Metallic Slit Structure
Yao, W., Sun, C., Gong, Q. & Chen, J. Controlling Surface-plasmon-polariton Launching with Hot Spot Cylindrical Waves in a Metallic Slit Structure. Nanotechnology 27, 385204 (2016). 访问链接Abstract
Plasmonic nanostructures, which are used to generate surface plasmon polaritions (SPPs), always involve sharp corners where the charges can accumulate. This can result in strong localized electromagnetic fields at the metallic corners, forming the hot spots. The influence of the hot spots on the propagating SPPs are investigated theoretically and experimentally in a metallic slit structure. It is found that the electromagnetic fields radiated from the hot spots, termed as the hot spot cylindrical wave (HSCW), can greatly manipulate the SPP launching in the slit structure. The physical mechanism behind the manipulation of the SPP launching with the HSCW is explicated by a semi-analytic model. By using the HSCW, unidirectional SPP launching is experimentally realized in an ultra-small metallic step-slit structure. The HSCW bridges the localized surface plasmons and the propagating surface plasmons in an integrated platform and thus may pave a new route to the design of plasmonic devices and circuits.
Li, Q.-T., et al. Polarization-independent and high-efficiency dielectric metasurfaces for visible light. Optics Express 24, 16309-16319 (2016). 访问链接
Tuning Fano resonances with a nano-chamber of air
Chen, J., et al. Tuning Fano resonances with a nano-chamber of air. Optics Letters 41, 2145-2148 (2016).
Song, X.-Y., et al. Efficient unidirectional launching of surface plasmons by a cascade asymmetric-groove structure. Nanoscale 8, 6777-6782 (2016). 访问链接
Ultra-small and broadband polarization splitters based on double-slit interference
Sun, C., Li, H., Gong, Q. & Chen, J. Ultra-small and broadband polarization splitters based on double-slit interference. Applied Physics Letters 108, 101106 (2016). 访问链接Abstract
An ultra-small and broadband polarization splitter is numerically and experimentally demonstrated based on the double-slit interference in a polymer-film-coated double-slit structure. The hybrid slab waveguide(air-polymer-Au) supports both the transverse-magnetic and transverse-electric modes. The incident beam from the back side can excite these two guided modes of orthogonally polarized states in the hybrid structure. By exploiting the difference slit widths and the large mode birefringence, these two guided modes propagate to the opposite directions along the front metal surface. Moreover, the short interference length broadens the operation bandwidth. Experimentally, a polarization splitter with a lateral dimension of only about 1.6 μm and an operation bandwidth of 50 nm is realized. By designing the double-slit structure in a hybrid strip waveguide, the device dimension can be significant downscaled to about 0.3 × 1.3 μm2. Such an ultra-small and broadband polarization splitter may find important applications in the integrated photonic circuits.
Plasmonic ridge waveguides with deep-subwavelength outside-field confinements
Sun, C., et al. Plasmonic ridge waveguides with deep-subwavelength outside-field confinements. Nanotechnology 27, 065501 (2016). 访问链接Abstract
Subwavelength plasmonic waveguides are the most promising candidates for developing planar photonic circuitry platforms. In this study a subwavelength metallic ridge waveguide is numerically and experimentally investigated. Differing from previous plasmonic waveguides, the metallic strip of the subwavelength ridge waveguide is placed on a thick metal film. It is found that the surface-plasmon-polariton (SPP) waveguide modes result from the coupling of the corner modes in the two ridge corners. The bottom metal film has a great influence on the SPP modes, and nearly all the evanescent fields of the SPP modes are tightly confined outside the ridge waveguide. Simulations show that 50% of the total power flow in the SPP mode can be confined outside the ridge waveguide with an area of only about λ 2/20. The propagation length is still about 10 times the plasmon wavelength. Through comparison with a metallic strip placed directly on the dielectric substrate, the proposed ridge waveguide exhibits a much higher sensing performance. This plasmonic ridge waveguide with deep-subwavelength outside-field confinements is of significance in a range of nano-optics applications, especially in nanosensing.
2015
Li, P., et al. Surface plasmon polaritons suppress photoresponse of colloidal CdS nanorods in nanogap. APPLIED PHYSICS EXPRESS 8, (2015).Abstract SCI被引用次数:0.
Colloidal CdS nanorods similar to 4.9 nm in diameter and similar to 60 nm long were positioned in gold bow-tie electrodes with a gap of similar to 50 nm by an AC dielectrophoresis process to construct optoelectronic devices. The fabricated devices exhibited an excellent photoresponse to white and blue light, but no response to green light. However, the response of the devices to white light could be degraded by green light. This is considered to be related to surface plasmon polaritons suppressing the generation of photo-carriers in the CdS nanorods. The results indicate that surface plasmons do not always benefit nano-optoeletronic devices. (C) 2015 The Japan Society of Applied Physics
Yao, W., et al. Efficient Directional Excitation of Surface Plasmons by a Single-Element Nanoantenna. NANO LETTERS 15, 3115-3121 (2015).Abstract SCI被引用次数:16.
Directional light scattering is important in basic research and real applications. This area has been successfully downscaled to wavelength and subwavelength scales With the development of optical antennas, especially single-element nano-antennas. Here, by adding an auxiliary resonant structure to a single-element plasmonic nanoantenna, we show that the highly efficient lowest-order antenna mode can be effectively transferred into inactive higher-order modes. On the basis of this mode conversion, scattered optical fields can be well manipulated by utilizing the interference between different antenna modes. Both broadband directional excitation of surface plasmon polaritons (SPPs) and inversion of SPP launching direction at different wavelengths are experimentally demonstrated as typical examples. The proposed strategy based on mode conversion and mode interference provides new opportunities for the design of nanoscale optical devices, especially directional nanoantennas.
Ultra-small wavelength splitters in a subwavelength plasmonic waveguide
Sun, C., Chen, J., Li, H. & Gong, Q. Ultra-small wavelength splitters in a subwavelength plasmonic waveguide. OPTICS LETTERS 40, 685-688 (2015).Abstract SCI被引用次数:3.
Miniaturizing optical devices beyond the diffraction limit is of great importance for high-integration photonic circuits. By directly fabricating a double-slit aperture structure of different sizes in a subwavelength plasmonic waveguide, an ultra-small plasmonic wavelength splitter is realized experimentally. Due to the different slit widths, the surface plasmon polaritons (SPPs) in the opposite directions exhibit anti-phase interferences. As a result, the SPPs excited at different wavelengths can be split to propagate in the opposite directions along the subwavelength plasmonic waveguide. The plasmonic wavelength splitter only occupies a footprint of about 1.4 mu m(2) on the metal surface, and the splitting wavelengths and their separation can be easily varied by adjusting the structural parameters. This provides it with important applications in the areas of the optical modulating, sensing, and computing networks in highly integrated plasmonic circuits. (C) 2015 Optical Society of America
Manipulating surface-plasmon-polariton launching with quasi-cylindrical waves
Sun, C., Chen, J., Yao, W., Li, H. & Gong, Q. Manipulating surface-plasmon-polariton launching with quasi-cylindrical waves. SCIENTIFIC REPORTS 5, 11331 (2015).Abstract SCI被引用次数:2.
Launching the free-space light to the surface plasmon polaritons (SPPs) in a broad bandwidth is of importance for the future plasmonic circuits. Based on the interference of the pure SPP component, the bandwidths of the unidirectional SPP launching is difficult to be further broadened. By greatly manipulating the SPP intensities with the quasi-cylindrical waves (Quasi-CWs), an ultra-broadband unidirectional SPP launcher is experimentally realized in a submicron asymmetric slit. In the nanogroove of the asymmetric slit, the excited Quasi-CWs are not totally damped, and they can be scattered into the SPPs along the metal surface. This brings additional interference and thus greatly manipulates the SPP launching. Consequently, a broadband unidirectional SPP launcher is realized in the asymmetric slit. More importantly, it is found that this principle can be extended to the three-dimensional subwavelength plasmonic waveguide, in which the excited Quasi-CWs in the aperture could be effectively converted to the tightly guided SPP mode along the subwavelength plasmonic waveguide. In the large wavelength range from about 600 nm to 1300 nm, the SPP mode mainly propagates to one direction along the plasmonic waveguide, revealing an ultra-broad (about 700 nm) operation bandwidth of the unidirectional SPP launching.

Pages