Coupling effect in a near-field object–superlens system

Liu, Zhengtong; Shalaev, Vladimir M.; Kildishev, Alexander V.

doi:10.1007/s00339-012-6780-2

Cited by 8 publications

(4 citation statements)

References 14 publications

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“…Indeed there is much to said for simply replacing the metamaterial with a random medium and characterizing the T-matrix of that medium, recognizing that increased scatter alone can improve image resolution, [9]. An important second problem that becomes clear from addressing this problem, is that one has to regard the object, metamaterial lens and the detector as a coupled system, because each is in the near field of the other [10]. A simple negative index slab treated in isolation is not going to provide high resolution fields in the image domain and care is required in estimating its actual transfer function.…”

Section: Introductionmentioning

confidence: 98%

Compressive sampling methods for superresolution imaging

Chuang

Dudley

Fiddy

2012

Image Reconstruction From Incomplete Data VII

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We investigate superresolution imaging using negative index metamaterials. Measurement of subwavelength scale features in the image domain is tedious and compressive sampling techniques are considered to alleviate this problem. A single detector (c.f. a single pixel camera geometry) is considered from which a high resolution image can be computed, which makes use of structured illumination for coding.

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Section: Introductionmentioning

confidence: 98%

Compressive sampling methods for superresolution imaging

Chuang

Dudley

Fiddy

2012

Image Reconstruction From Incomplete Data VII

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show abstract

“…Recently, we have studied the coupling effect in a nearfield object-superlens system. 30 We have found out that the coupling effect between the object and the superlens significantly alters the field distribution around both the object and the superlens and creates complex near-field interference patterns. By using the coupling effect, it is possible to design a nanoantenna-superlens system to translate hot-spots with mismatched permittivities, eliminating the need for composite materials.…”

mentioning

confidence: 95%

Near field enhancement in silver nanoantenna-superlens systems

Shalaev

Kildishev

2012

Applied Physics Letters

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We demonstrate near field enhancement generation in silver nanoantenna-superlens systems via numerical modeling. Using near-field interference and global optimization algorithms, we can design nanoantenna-superlens systems with mismatched permittivities, whose performance can match those with matched permittivities. The systems studied here may find broad applications in the fields of sensing, such as field-enhanced fluorescence and surface-enhanced Raman scattering, and the methodology used here can be applied to the designing and optimization of other devices, such as two-dimensional near field focusing lens.

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“…However the effective permittivity of a metal-dielectric composite depends on many fabrication conditions and is difficult to control, and the effective medium theory may not accurately describe the optical properties of the composite. This uncertainty significantly limits the actual application of the nanoantenna-superlens system.Recently we have studied the coupling effect in a near-field object-superlens system [3]. We have found out that the coupling effect between the object and the superlens significantly alters the field distribution of both the object and the superlens.…”

mentioning

confidence: 99%

“…Recently we have studied the coupling effect in a near-field object-superlens system [3]. We have found out that the coupling effect between the object and the superlens significantly alters the field distribution of both the object and the superlens.…”

mentioning

confidence: 99%

Designing a nanoantenna-superlens system for sensing applications

Liu

Shalaev

et al. 2012

IEEE Photonics Conference 2012

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We demonstrate near field enhancement generation in a silver nanoantenna-superlens system. Using near-field coupling effect and genetic algorithm for optimization we can design a nanoantenna-superlens system with mismatched permittivities for sensing applications.Optical nanoantennas and superlens have many potential applications such as biosensors, near-field scanning optical microscopy (NSOM), quantum optical information processing, enhanced Raman scattering as well as other optical processes [1]. A nanoantenna is usually an ensemble of metal nanoparticles, most commonly paired metal nanoparticles, and it can generate "hot spots" -highly localized and significantly enhanced near-field electromagnetic fields. A superlens is a slab with negative permittivity that satisfy the condition 1 2     , where 1  and 2  are the permittivities of the superlens and the host material respectively. A superlens can focus propagating waves and enhance evanescent waves, therefore resolve near-field features much smaller than the wavelength.In our previous study we have shown that if we place a nanoantenna close to a near-field superlens, the hot spot generated by the nanoantenna can be translated to the other side of the superlens [2]. In the study, to satisfy the operational condition of superlens, we had to use a metal-dielectric composite superlens to match the permittivity of the host material. However the effective permittivity of a metal-dielectric composite depends on many fabrication conditions and is difficult to control, and the effective medium theory may not accurately describe the optical properties of the composite. This uncertainty significantly limits the actual application of the nanoantenna-superlens system.Recently we have studied the coupling effect in a near-field object-superlens system [3]. We have found out that the coupling effect between the object and the superlens significantly alters the field distribution of both the object and the superlens. By using the coupling effect, it is possible to design a nanoantenna-superlens system to translate hot-spots with mismatched permittivities. In this summary, we present our findings on using pure silver as a superlens for such a nanoantenna-superlens system.The side view and top view of a unit cell of the system we studied are shown in Fig. 1. An elliptical silver nanoantenna pair is embedded in a SiO 2 substrate. A silver superlens is placed above the nanoantenna. A thin SiO2 cover layer is again placed on top of the superlens. The incoming light is assumed to be a plane wave normally incident from bottom with a wavelength of 633 nm. The wavelength is chosen because it is a most common laser wavelength, and in actual applications can be set to any wavelength of interests. At this wavelength the permittivity of silver is -17.9+0.477i, and the permittivity of SiO 2 is 2.12, therefore they mismatch and do not satisfy the operational condition of superlens. Figure 1 (a) Side view of a unit cell, (b) Top view of a unit cellWe used a commercial finite element m...

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Coupling effect in a near-field object–superlens system

Cited by 8 publications

References 14 publications

Compressive sampling methods for superresolution imaging

Compressive sampling methods for superresolution imaging

Near field enhancement in silver nanoantenna-superlens systems

Designing a nanoantenna-superlens system for sensing applications

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