Congratulations for our new paper in journal of Optical Materials

Electro-Optical Switch based on One-Dimensional Graphene-Plasmonic Crystals

Sakineh Almasi Monfared, Mahmood Seifouri, Seyedeh Mehri Hamidi,
Seyed Majid Mohseni

In the present study, an electro-optical switch using one-dimensional plasmonic photonic crystals and bilayer graphene was demonstrated experimentally and theoretically. The optical modes of band gap in crystal can be tuned due to the unique optical properties of plasmonic surface resonance at grating and graphene layers. In addition, the excitation of the periodic arrays of metallic resulted in exciting plasmonic surface lattice resonance and creating two reflectance modes for magnetic polarization at 54° incidence angle. Further, the chemical potential of graphene was controlled by applying a gate voltage to achieve an optoelectronic switching operation. Applying voltage of 1 V led to a sharp increase in the relative permittivity of bilayer graphene around the first resonance. Thus, the light was absorbed, its intensity deceased, and the plasmonic resonance wavelength shifted by a value of ~9 nm. Based on the results, using this new kind of structures had advantages such as small size, low power consumption, easier fabrication, and less manufacturing cost, as well as the high controllability of conductivity compared to the other methods.

News On Magneto-Electronic

In this days, the Journal of Nano Energy publishes a new paper entitled as “A multiferroic module for biomechanical energy harvesting”

The growth and ubiquitous use of mobile electronics and the Internet of Things is driving a rapid surge in research into self-powered personal electronic devices and sensor networks. Scavenging human biomechanical energy via piezoelectricity or triboelectricity is a viable strategy to address the limited lifespan and periodic recharging issues of conventional batteries. Here, we report a self-charging multiferroic module for sustainable operation of personal mobile electronics, by exploiting multiferroic composites in response to biomechanical energy via mechano magneto-electric energy conversion. The multiferroic energy harvesting module consists of a movable permanent magnet that transduces mechanical energy into magnetic energy, and a pair of piezoelectric/ magnetostrictive magnetoelectric (ME) laminates that function to convert magnetic energy into electrical energy. The multiferroic energy harvesting device exhibits an efficient mechano-magneto-electric energy conversion performance with open-circuit voltage of  ~ 17 V and short-circuit current ~ 7.2 µA under mechanical excitation equivalent to human running. This multiferroic module has been demonstrated during human running as a viable power source for temperature and humidity sensors, Bluetooth arphones and night running indicators, which suggests application in sustainable personal electronics and even the Internet of Things.

Congratulations for our new paper in Journal of Nanoscale

Nanophotonic Structures with Optical Surface modes for Tunable Spin Current Generation

P.V. Penkina, D.O. Ignatyeva, P.O. Kapralov, S.K. Sekatskii, M. Nur-E-Alam, M. Vasiliev, K. Alameh, A.V. Gopal, Y.Song, S.M. Hamidi, A.K. Zvezdin and V.I. Belotelov

Spintronics has been demonstrated to be very promising for data processing and storage. However, the problem of the efficient and tunable spin current generation still seeks for new solutions. We propose a novel type of photonic-crystal (PC) based structures for efficient and tunable optically-induced spin generation via the Spin Seebeck and inverse spin Hall effects. We experimentally demonstrate that excitation of the surface modes localized at the PC surface covered with materials with giant spin orbit coupling allows us to enhance light-matter interaction and to increase the efficiency of the optical generation of spin currents. Moreover, it is shown that spintronic PC-based nanostructures allow for tunability and miniaturization of the spintronic system via additional patterning.

News

The Journal of ACS Nano published a paper entitled as “Fano Resonant Aluminum Nanoclusters for Plasmonic Colorimetric Sensing”

Abstract- Aluminum is an abundant and high-quality material for plasmonics with potential for large-area, low-cost photonic technologies. Here we examine Aluminum nanoclusters, with plasmonic Fano resonances that can be tuned from the near-UV into the visible region of the spectrum. These nanoclusters can be designed with specific chromaticities in the blue green region of the spectrum and exhibit a remarkable spectral sensitivity to changes in the local dielectric environment. We show that such structures can be used quite generally for colorimetric Localized Surface Plasmon Resonance (LSPR) sensing, where the presence of analytes is detected by directly observable color changes rather than through photodetectors and spectral analyzers. To quantify our results and provide a metric for optimization of such structures for colorimetric LSPR sensing, we introduce a Figure of Merit based on the color perception ability of the human eye.

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In this days, Journal of Optics Express publishes a new paper entitled as “Local field enhancement using a photonic-plasmonic nanostructure”

Over the last few years, optical nanoantennas are continuously attracting interest owing to their ability to efciently confne, localize resonance, and signifcantly enhanced electromagnetic felds at a subwavelength scale. However, such strong confnement can be further enhanced by using an appropriate combination of optical nanoantennas and Slanted Bound states in the continuum cavities. Here, we propose to synergistically bridge the plasmonic nanoantennas and high optical quality-factor cavities to numerically demonstrate six orders of magnitude local intensity enhancement without critical coupling conditions. The proposed hybrid system paves a new way for applications requiring highly confned felds such as optical trapping, optical sensing, nonlinear optics, quantum optics, etc.

News On Plasmonic

In this days, the Journal of Plasmonics publishes a new paper entitled as “Tuning of SPR for Colocalized Characterization of Biomolecules Using Nanoparticle-Containing Multilayers”

In this contribution, we quantify the fine-tuning of surface plasmon resonance via nanoparticle coating of gold SPR chips. We target preparation of atomically flat surface with defined charge, needed for scanning probe characterization of biomolecules, with simultaneous optimization of in situ SPR sensitivity during immobilization of these molecules. Using total internal reflection ellipsometry, we show that the goal can be achieved by combination of charge-stabilized silver nanoparticles over underlying gold chip of reduced thickness. The provided formulas for optimal silver to gold thickness relation are valid for arbitrary analyte and the method was experimentally verified on binding of Rtt103 protein.

Congratulations for Our new paper in Journal of Optik

Light emitting polymers in two dimensional plasmonic multi wavelength random laser

S. F. Haddawi, A.K. Kodeary, N.S. Shnan, Hammad R. Humud, S. M. Hamidi

Red, Green and Blue Multi wavelength lasing is desired in two dimensional flexible plasmonic multi-layer structure based on light emitting polymers and gold nanostructure. For this purpose, gold nano-structure is covered by three different light emitting polymers with poly-vinyl-pyrolydone as spacer layers. To achieve multi-wavelengths random laser, these six layers are coated over the poly-dimethyl siloxane substrate by main surface roughness and the sample is pumped by nanosecond green laser. The lasing due to band-edge lattice plasmons in arrays of plasmonic nano rods in a homogeneous environment is collected by spectrometer. Our results show emission peaks for every wavelength region with the minimum value of threshold lasing and the maximum of emission intensity.

Congratulations for our new paper in Journal of Optical and quantum electronics

The effect of dye concentration and cell thickness on dye–polymer random laser action

R. A. Ejbarah, J. M. Jassim, S. M. Hamidi

This study has been aimed to explore the effect of dye concentration, cell thickness, and polymers on the characteristics of random laser (emission spectrum, full width at half maximum (FWHM), and lasing threshold). It has been found that the properties of the random laser are affected by these three parameters significantly, as it was observed that the emission spectrum reached its best value when adding the of Polyvinylpyrrolidone (PVP) polymer. As for the FWHM and the laser threshold, their value decreased from 38 nm to 35 nm and from 0.71 A to 0.68 A respectively after adding the polymeric material. These results were achieved at concentration of 5*10^-4 M and cell thickness 0.1 cm. Improving the properties of random lasers is considered a significant step in creating optical devices useful in medical applications and biosensors.

News On Plasmonic

The Journal of ACS Photonics published a paper entitled as “Reducing the Complexity: Enantioselective Chiral Near-Fields by Diagonal Slit and Mirror Configuration”

ABSTRACT: We report an easy-to-fabricate plasmonic design consisting of diagonal slits in a metallic film on top of a mirror for the generation of chiral near-fields of one single handedness. Our numerical investigations show that the distance between the two layers is crucial for the properties of this design. While the far-field response can be used to identify layer distances with strong chiral near-fields, this distance must be small enough to additionally ensure single-handedness of the respective fields close to
the slit area. The fields of interest can be easily accessed by chiral molecules because they are located within the slits. Based on this finding, we propose and numerically verify a novel technique for chiroptical spectroscopy in a reflection geometry.

Congratulations for our new paper in Optik Journal

Red and Blue color production by flexible all-dielectric structure

N. Roostaei, N. S. Shnan, S. M. Hamidi

Color production by using plasmonic structures has been extensively studied. Due to the inherent damping of plasmons, such plasmonic structures are challenging to produce high-resolution color. Recently, color production by using all-dielectric metasurfaces has attracted much attention. Here, all-dielectric structure with different dimensions were fabricated by a nanoimprint lithography method. Color production in both reflection and transmission modes and imaging using metasurfaces were performed. The refractive index of our fabricated metasurface was calculated, and the effect of refractive index changes onto the loss, transparency, and also resolution of image and color production has been investigated. By considering the low cost and high resolution, this research will be useful for the structural color production in industrial applications.