Microwave gain medium with negative refractive index

Ye, Dexin; Chang, Kihun; Ran, Lixin; Xin, Hao

doi:10.1038/ncomms6841

Cited by 57 publications

(40 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For instance, a grating of wide metallic strips periodically loaded with lumped elements has been proposed to design the metasurfaces with gain for microwave cloaking [50]. In addition, subwavelength structures with a large amount of gain can be realized by using multilayered structures [48], microwave and optical metastructures with gain [71][72][73][74][75], etc. In particular, the effective gain media with pure permittivity or permeability have also been demonstrated in core-shell composites [76].…”

Section: (C)mentioning

confidence: 99%

Electromagnetic Impurity-Immunity Induced by Parity-Time Symmetry

Luo

Lai

2018

Phys. Rev. X

View full text Add to dashboard Cite

Impurities usually play an important role in modifying the bulk properties of electronic or electromagnetic materials. In this work, we demonstrate a way to break this discipline and realize the extraordinary physical property of impurity-immunity, which leads to perfect transmission irrespective of embedded impurities of almost any material and shape. This extraordinary property comes from the exceptional points of a pair of parity-time (PT)-symmetric metasurfaces sandwiching a slab of epsilonnear-zero medium. By systematically investigating the PT-symmetric metasurfaces sandwiching a slab of dielectrics or metamaterials, we obtain the two complementary solutions of exceptional points corresponding to perfect transmission. Interestingly, when the permittivity of the slab approaches zero, the two solutions of exceptional points coalesce into one exceptional point. At such a critical point, we find that the original "doping" effect of impurities in epsilon-near-zero media, proposed by Nader Engheta's group very recently [I. Liberal et al., Science 355, 1058(2017], is significantly suppressed. Our work shows that exceptional points can be used to eliminate scattering of impurities in a bulk medium.

show abstract

Section: (C)mentioning

confidence: 99%

Electromagnetic Impurity-Immunity Induced by Parity-Time Symmetry

Luo

Lai

2018

Phys. Rev. X

View full text Add to dashboard Cite

show abstract

“…The recently developed plasmon lasers showed that these dampings can be fully compensated by gain medium at the lasing state [27][28][29][30][31][32][33][34][35][36][37][38]. This intrinsic merit has great potential to enhance the performance of devices based on plasmonic resonance phenomena [39][40][41][42][43][44][45]. One example is the plasmon laser for gas phase detection where the mechanism of the sensing process relies on surface defect state modification of semiconductor material [46].…”

mentioning

confidence: 99%

Lasing Enhanced Surface Plasmon Resonance Sensing

Wang

et al. 2017

Nanophotonics

View full text Add to dashboard Cite

Abstract:The resonance phenomena of surface plasmons has enabled development of a novel class of noncontact, real-time and label-free optical sensors, which have emerged as a prominent tool in biochemical sensing and detection. However, various forms of surface plasmon resonances occur with natively strong non-radiative Drude damping that weakens the resonance and limits the sensing performance fundamentally. Here we experimentally demonstrate the first lasing-enhanced surface plasmon resonance (LESPR) refractive index sensor. The figure of merit (FOM) of intensity sensing is~84,000, which is about 400 times higher than state-of-the-art surface plasmon resonance (SPR) sensor. We found that the high FOM originates from three unique features of LESPR sensors: high-quality factor, nearly zero background emission and the Gaussian-shaped lasing spectra. The LESPR sensors may form the basis for a novel class of plasmonic sensors with unprecedented performance for a broad range of applications. Keywords:Surface plasmon resonances, stimulated emission, plasmon lasers, sensors Surface plasmons are quasiparticles of coupled photons and electrons excited at the metal surface [1]. They can be tightly localised at the metal surface and thus highly sensitive to its dielectric environment. Surface plasmon sensors operate on the principle that small changes in refractive index at the vicinity of metal surface can result in a shift of surface plasmon resonance, which can be detected at optical far field, allowing non-contact, realtime and label-free sensing and detection [2][3][4][5][6]. In the past two decades, the surface plasmon resonance (SPR) sensors based on propagating surface plasmon polaritons have become a prominent tool for characterising and quantifying biomolecular interactions and are perhaps the most extensively utilised optical biosensors [3,7,8]. However, the propagating surface plasmons on flat surface cannot be directly excited due to their large momentum. In most SPR sensors, the Kretschmann configuration of attenuated total reflection is used to excite surface plasmons, which requires precise adjustment of the incident angle of the probing radiation [3,7,8]. Therefore, it remains a challenge for SPR sensors to have point-of-care performance and satisfy modern nanobiotechnology architectures [3,7,9].Localised surface plasmons (LSPs) are another type of surface plasmons that have begun to be used in sensors recently [4][5][6]. In contrast to its propagating counterpart, LSPs can be excited directly in metallic structures with dimensions less than half the wavelength. Single metal particle with tunable spectra and enhanced local field can be used for sensing, which is much more suitable for the modern nanobiotechnology architectures [9][10][11][12][13][14][15][16][17][18][19][20]. However, localised surface plasmon resonance (LSPR) sensors are with orders of magnitude lower sensitivity compared with propagating SPR sensors [8,13]. Only when measuring refractive index change in the nanometer vicinity to the meta...

show abstract

“…Depending on the theoretical analysis of the SRRs proposed in [30,31], magnetic resonance is motivated by the electromotive force around the circumference of the split rings. Considering an infinite array of such SRRs arranged in three orthogonal directions with a spatial period of d and an incident magnetic field polarized along the y direction, that is, perpendicular to the SRRs, there would be an electromotive force and an induced current I along the rings, satisfying the following:…”

Section: Model and Theoretical Analysismentioning

confidence: 99%

A Novel Tunable Triple-Band Left-Handed Metamaterial

Elsherbeni

et al. 2017

International Journal of Antennas and Propagation

View full text Add to dashboard Cite

A novel tunable triple-band left-handed metamaterial (LHM) composed of a single-loop resonator (SLR) and a variable capacitorloaded short wire pair (CL-SWP) printed on both sides of a substrate is presented in this paper. The CL-SWP-based metamaterial (MTM) is a novel single-sided LHM. It is theoretically analyzed capable of extracting tunable negative permeability and a wideband negative permittivity. We ran simulations for the CL-SWP-based MTM, the SLR-based MTM, and the proposed LHM. Together with the measured results, it is identified that this novel LHM exhibits a tunable triple-band left-handed (LH) property. With the increase of the loaded capacitance, one LH band is relatively stable, while the other two are moving towards lower frequencies with their bandwidth getting wider and narrower, respectively. The surface current density distributions indicate that the first LH band is mainly decided by the SLR, one of the rest 2 LH bands is mainly decided by the CL-SWP, and the other one is decided by the SLR and CL-SWP together.

show abstract

Microwave gain medium with negative refractive index

Cited by 57 publications

References 37 publications

Electromagnetic Impurity-Immunity Induced by Parity-Time Symmetry

Electromagnetic Impurity-Immunity Induced by Parity-Time Symmetry

Lasing Enhanced Surface Plasmon Resonance Sensing

A Novel Tunable Triple-Band Left-Handed Metamaterial

Contact Info

Product

Resources

About