Far-field disentanglement of modes in hybrid plasmonic-photonic crystals by fluorescence nano-reporters

Nanophotonics ◽  
2013 ◽  
Vol 2 (3) ◽  
pp. 173-185 ◽  
Author(s):  
Simona Ungureanu ◽  
Branko Kolaric ◽  
Jianing Chen ◽  
Rainer Hillenbrand ◽  
Renaud A. L. Vallée
Keyword(s):  
Photonic Crystals ◽  
Near Field ◽  
Optical Microscope ◽  
Hybrid Structure ◽  
Silver Layer ◽  
Far Field ◽  
Polystyrene Spheres ◽  
Resonance Modes ◽  
Field Patterns ◽  
Plasmonic Structures

AbstractIn this paper, the resonance modes exhibited by a hybrid nanostructure have been disentangled in the far-field owing to narrow-band fluorescence nano-reporters. Hybrid plasmonic-photonic crystals were fabricated using large (457 nm) monodisperse polystyrene spheres self-assembled into 2D photonic crystals and subsequently coated by a 30 nm thick silver layer. Such structures exhibit a complex resonance pattern, which has been elucidated owing to numerical simulations and electric near-field patterns obtained with a scattering type scanning near-field optical microscope (s-SNOM). For the sake of disentangling the resonance modes of the hybrid structure in the far-field, different types of semiconductor quantum dots (QDs), acting as nano-reporters of the local interactions, were dispersed on top of distinct structures. Depending on the relative overlap of the emission spectrum of a particular type of QDs with the resonance features of the hybrid structure, we affect their emission rate in a unique way, as a consequence of the complex interaction occurring between the plasmo-photonic modes and the excitons. Such plasmonic structures appear to be particularly relevant for fluorescence-based sensing devices.

scholarly journals Dye-doped spheres with plasmonic semi-shells: Lasing modes and scattering at realistic gain levels

2013 ◽  
Vol 4 ◽  
pp. 974-987 ◽  
Author(s):  
Nikita Arnold ◽  
Boyang Ding ◽  
Calin Hrelescu ◽  
Thomas A Klar
Keyword(s):  
Cross Section ◽  
Near Field ◽  
Field Enhancement ◽  
Higher Order ◽  
Silver Layer ◽  
Far Field ◽  
Spectral Features ◽  
Polystyrene Spheres ◽  
Higher Order Modes ◽  
Lasing Modes

We numerically simulate the compensation of absorption, the near-field enhancement as well as the differential far-field scattering cross section for dye-doped polystyrene spheres (radius 195 nm), which are half-covered by a silver layer of 10–40 nm thickness. Such silver capped spheres are interesting candidates for nanoplasmonic lasers, so-called spasers. We find that spasing requires gain levels less than 3.7 times higher than those in commercially available dye-doped spheres. However, commercially available concentrations are already apt to achieve negative absorption, and to narrow and enhance scattering by higher order modes. Narrowing of the plasmonic modes by gain also makes visible higher order modes, which are normally obscured by the broad spectral features of the lower order modes. We further show that the angular distribution of the far-field scattering of the spasing modes is by no means dipole-like and is very sensitive to the geometry of the structure.

Comparison of ultralow-sidelobe-antenna far-field patterns using the planar-near-field method and the far-field method

1995 ◽  
Vol 37 (6) ◽  
pp. 7-15 ◽  
Author(s):  
M.H. Francis ◽  
A.C. Newell ◽  
K.R. Grimm ◽  
J. Hoffman ◽  
H.E. Schrank
Keyword(s):  
Near Field ◽  
Field Method ◽  
Far Field ◽  
Field Patterns

Near-field scanning optical microscopy local luminescence studies of rhodamine dye

Open Physics ◽  
2010 ◽  
Vol 8 (3) ◽  
Author(s):  
Petr Klapetek ◽  
Juraj Bujdák ◽  
Jiří Buršík
Keyword(s):  
Time Domain ◽  
Near Field ◽  
Optical Microscope ◽  
Far Field ◽  
Luminescence Signal ◽  
Local Topography ◽  
Field Radiation ◽  
Scanning Optical Microscopy ◽  
Rhodamine Dye ◽  
Near Field Scanning

AbstractThis article presents results of near-field scanning optical microscope measurement of local luminescence of rhodamine 3B intercalated in montmorillonite samples. We focus on how local topography affects both the excitation and luminescence signals and resulting optical artifacts. The Finite Difference in Time Domain method (FDTD) is used to model the electromagnetic field distribution of the full tip-sample geometry including far-field radiation. Even complex problems like localized luminescence can be simulated computationally using FDTD and these simulations can be used to separate the luminescence signal from topographic artifacts.

scholarly journals Improved Handset Antenna Performance via an Electrically Extended Ground Plane

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Shirook M. Ali ◽  
Huanhuan Gu ◽  
Kelce Wilson ◽  
James Warden
Keyword(s):  
Absorption Rate ◽  
Specific Absorption Rate ◽  
Near Field ◽  
Ground Plane ◽  
Practical Approach ◽  
Far Field ◽  
Specific Absorption ◽  
Antenna Performance ◽  
Field Patterns ◽  
Surface Metal

A novel and practical approach is presented providing improved antenna performance without enlarging the antenna or the ground plane. The approach electrically extends the ground plane using wire(s) that behave as surface metal extensions of the ground plane. The wire extensions can be accommodated within typical handset housing or as part of the stylish metal used on the handset’s exterior perimeter; hence don’t require enlargement of the device. Consequently, this approach avoids the costs and limitations traditionally associated with physically lengthening of a ground plane. Eight variations are presented and compared with baseline antenna performance. Both far-field patterns and near-field electromagnetic scans demonstrate that the proposed approach controls the electrical length of the ground plane and hence its chassis wavemodes, without negatively impacting the characteristics of the antenna. Improvements in performance of up to 56% in bandwidth at 900 MHz and up to 12% in efficiency with a reduction of up to 12% in the specific absorption rate (SAR) are achieved. An 8% increase in efficiency with a 1.3% improvement in bandwidth and a 20% reduction in SAR is achieved at 1880 MHz. Thus, improvements in bandwidth are achieved without compromising efficiency. Further, improvements at lower frequencies do not compromise performance at higher frequencies.

The analysis of near and far field pattern through mode analysis and FFT in a finite periodic dielectric gratings

2015 ◽  
Vol 17 (1) ◽  
pp. 82-90 ◽  
Author(s):  
Tae-Bong Lee ◽  
Min-Nyeon Kim
Keyword(s):  
Near Field ◽  
Bloch Wave ◽  
Wave Number ◽  
Mode Analysis ◽  
Field Pattern ◽  
Far Field ◽  
Content Type ◽  
Coupled Method ◽  
Field Patterns ◽  
Dielectric Gratings

Purpose – The purpose of this paper is to analyze far and near field emitted field patterns through more exact calculation of the modes formed in finite periodic dielectric gratings. Design/methodology/approach – For the mode calculation, equations are newly defined by applying vertical boundary condition on the assumption that transverse electric modes are generated in the structure. After finding modes, near field patterns are calculated using the wave number and coefficient of the mode. Findings – Additionally, the results from these calculations are compared with that of the rigorous-coupled method. Finally, far field patterns are derived by applying fast Fourier transform to near field patterns and also compared with the results of rigorous-coupled method. Research limitations/implications – For convenience of coordinate, we use rectangular coordinate, though the shape of radome is a hemisphere. Practical implications – In this paper, the authors derive more exact near field patterns without the assumption of infiniteness so that these results can be used practically for a making real frequency-selective structure. Originality/value – Conventional periodic finite dielectric gratings analysis has been done using Floquet–Bloch wave theory, coupled-mode, rigorous-coupled method which is based on the assumption of infiniteness of the structure.

scholarly journals Femtosecond Laser Precision Engineering: From Micron, Submicron, to Nanoscale

2021 ◽  
Vol 2021 ◽  
pp. 1-22
Author(s):  
Zhenyuan Lin ◽  
Minghui Hong
Keyword(s):  
Femtosecond Laser ◽  
High Efficiency ◽  
Near Field ◽  
Ambient Air ◽  
Optical Microscope ◽  
Far Field ◽  
Large Area ◽  
Precision Engineering ◽  
Processing Strategies ◽  
Near Field Effect

As a noncontact strategy with flexible tools and high efficiency, laser precision engineering is a significant advanced processing way for high-quality micro-/nanostructure fabrication, especially to achieve novel functional photoelectric structures and devices. For the microscale creation, several femtosecond laser fabrication methods, including multiphoton absorption, laser-induced plasma-assisted ablation, and incubation effect have been developed. Meanwhile, the femtosecond laser can be combined with microlens arrays and interference lithography techniques to achieve the structures in submicron scales. Down to nanoscale feature sizes, advanced processing strategies, such as near-field scanning optical microscope, atomic force microscope, and microsphere, are applied in femtosecond laser processing and the minimum nanostructure creation has been pushed down to ~25 nm due to near-field effect. The most fascinating femtosecond laser precision engineering is the possibility of large-area, high-throughput, and far-field nanofabrication. In combination with special strategies, including dual femtosecond laser beam irradiation, ~15 nm nanostructuring can be achieved directly on silicon surfaces in far field and in ambient air. The challenges and perspectives in the femtosecond laser precision engineering are also discussed.

Near‐field and far‐field patterns of phase‐locked semiconductor laser arrays

1983 ◽  
Vol 42 (6) ◽  
pp. 495-497 ◽  
Author(s):  
D. R. Scifres ◽  
W. Streifer ◽  
R. D. Burnham ◽  
T. L. Paoli ◽  
C. Lindström
Keyword(s):  
Semiconductor Laser ◽  
Near Field ◽  
Far Field ◽  
Laser Arrays ◽  
Field Patterns ◽  
Semiconductor Laser Arrays

scholarly journals Complex Analysis of Emission Properties of LEDs with 1D and 2D PhC Patterned by EBL

Coatings ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 748
Author(s):  
Lubos Suslik ◽  
Jaroslava Skriniarova ◽  
Jaroslav Kovac ◽  
Dusan Pudis ◽  
Anton Kuzma ◽  
...  
Keyword(s):  
Complex Analysis ◽  
Near Field ◽  
Optical Microscope ◽  
Considerable Effect ◽  
Light Extraction Efficiency ◽  
Far Field ◽  
Light Emitting ◽  
Surface Emission ◽  
Emission Enhancement ◽  
Radiation Properties

In this paper, we present the optical and electrical properties of surface-patterned GaAs-based Multiquantum Well (MQW) light emitting diodes (LEDs) with one- and two-dimensional photonic crystal (PhC) structures. Optical properties were analyzed in the near and far field, measured by a near-field scanning optical microscope and with a goniophotometer. We demonstrated a strong effect of patterned PhC on the radiation properties and the light extraction efficiency. Enormous surface emission enhancement reaching 110% confirmed the strong effect of the patterned structure on the coupling of the guided modes into the surface emission. Additionally, the considerable effect of the PhC structure diffraction on radiation pattern was confirmed in the near and far field and is in good agreement with the simulated shape of the optical field.

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