Magnetoplasmonics Lab

Archives November 2022

News on Energy Harvesting

In these days, the Journal of Materials Chemistry A published a new paper entitled as “Energy harvesting of fully-flexible magnetoelectric composites using a piezoelectric P(VDF-TrFE) and magnetostrictive CoFe2O4 nanofiber”

In response to the increasing demand for wearable devices, the development of flexible energy harvesters as self-powering systems to replace batteries is accelerating. Flexible magnetoelectric (ME) composites, which can convert practical electrical energy from a magnetic field source, have attracted considerable attention for application in wearable magnetic devices. In this study, a 2-2 type structure based on a flexible magnetostrictive film with cobalt ferrite (CoFe2O4, CFO) nanofibers was adopted to obtain appropriate flexibility and magnetoelectric properties. The flexible ME composite was completely fabricated by coating piezoelectric poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) onto a magnetostrictive film composed of CFO nanofibers and a polyimide matrix. Moreover, we conducted a multiphysics simulation and theoretically proved that a higher strain could be transferred to the piezoelectric layer at higher CFO concentrations, thus resulting in the generation of high magnetoelectric signals from the ME composite. The flexible, robust, and mechanically-stable ME composite reached an output voltage of 0.52 V and a current signal of 25 nA under an external AC magnetic field at 1 Hz. This study led to the development of a fully-flexible design of a bilayer ME composite prepared using a simple fabrication process providing a future avenue for wearable magnetoelectric energy harvesting.

Congratulations for our new Paper in Journal Of ACS Applied Nano Materials

Congratulations for our new Paper in Journal Of ACS Applied Nano Materials:

Plasmonic Eyeglasses Based on Gold Nanoparticles for Color Vision Deficiency Management
N. Roostaei and S. M. Hamidi*

Color vision deficiency (CVD), or color blindness, is a common ocular disorder that prohibits the recognition of different colors, from which many people suffer worldwide (8-10% of males and 0.4-0.5% of females). Despite numerous efforts, no definitive cure for color blindness has yet been discovered, but many color filter-based aids such as tinted glasses and contact lenses have been developed to help color blind people. This work is the first to fabricate plasmonic eyeglasses based on gold nanoparticles using two innovative methods, i.e., the simple self-assembly technique and heat treatment of gold thin films, and to evaluate them for color blindness management. The proposed plasmonic eyeglasses were simulated using the finite-difference time-domain (FDTD) method, and a good agreement between experimental and simulation results was obtained. The proposed plasmonic eyeglasses based on gold nanoparticles are more selective than commercial Enchroma and VINO glasses because of the tunability of plasmonic properties of gold NPs by controlling their morphology, which provides insights for applications of color vision deficiency improvement.

کارگاه آموزش نرم افزار طراحی اپتیکی زیمکس

پژوهشکده لیزر و پلاسمای دانشگاه شهید بهشتی کارگاه آموزشی نرم افزار طراحی سامانه های اپتیکی


:را بصورت آنلاین برگزار می کند

چهاردهم آذرماه 1401 ((با تخفیف ویژه برای دانشجویان دانشگاه شهید بهشتی و سایر دانشگاه ها))

09399119912 شماره تماس جهت ثبت نام

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 5859- 8311- 3224- 5258 بانک تجارت بنام سهیلا اکبری

مرکز فناوری کوانتومی دانشگاه شهید بهشتی تهران برگزار می کند: سمینار آشکارسازهای تک فوتون

:مرکز فناوری کوانتومی پژوهشکده لیزر و پلاسما دانشگاه شهید بهشتی تهران برگزار می کند

سمینار آشکارسازهای تک فوتون

سالن آمفی تئاتر پژوهشکده لیزر و پلاسمای دانشگاه شهید بهشتی تهران

بیست و نهم آبان ماه 1401

News On Plasmonic Switches

In these days, the Journal of Plasmonics published a new paper entitled as “Switchable Gratings for Ultracompact and Ultrahigh Modulation Depth Plasmonic Switches”

Plasmonic interconnects present a compact platform for high modulation-depth optical switches. Conventional plasmonic switching approaches depend on modifying the dispersion of the surface plasmon polariton (SPP) wave at the metal/dielectric interface. Here, we introduce a novel scheme for ultracompact and high modulation depth (MD) plasmonic switching using a phase-change material-based switchable grating consisting of antimony trisulfide (Sb2S3). In its ON state, the switchable grating excites surface plasmon polaritons (SPP) and bulk plasmon polaritons (BPPs) in plasmonic films and hyperbolic metamaterials (HMMs), respectively. The SPP switch has a footprint of 23.1 µm2 and a MD of up to 40 dB. The BPP switch has a footprint of 13.12 μm2 and a MD of 29.7 dB. The BPP switch enjoys a broadband MD from 299 to 375 THz. Concurrently, we show that the same switchable grating on plasmonic film and on HMM is a refection-based optical switch. Finally, we present a novel scheme for non-local control over the spontaneous emission rate and out-coupled power from emitters embedded in HMMs.

Congratulations for our new paper in Journal Of Nanoscale

امیترهای تراهرتز اسپینترونیکی بهینه مبتنی بر نانوساختارهای فرومغناطیسی

سیده مریم حسینی، سیده مهری حمیدی* ، فاضل جهانگیری

چکیده: تابش الکترومغناطیسی تراهرتز برای کاربردهای فراوانی از جمله تصویربرداری و طیف سنجی سودمند است. در این مقاله، امیتر دولایه ای Fe/Pt ،Glass ،sapphireبا توجه به ضخامت لایه ها بهینه شد و با مدلسازی میدان تابشی تراهرتز، تاثیر زیرلایه های
Tungstenو MgOبر ضخامت بهینه امیتر تراهرتز اسپینترونیکی Fe/Ptبررسی شد. مدل استفاده شده در این مقاله، قطبش اسپینی،
.پخش و تجمع اسپینی و ویژگی های الکتریکی و نوری لایه ها را در نظر میگیرد

Congratulations for our new paper in Journal of Applied Physics A

The bull’s‑eye structure as a new plexcitonic circular grating

T. Mahinroosta, S. M. Hamidi*

We theoretically demonstrate the strong coupling between plasmons and excitons in the plexcitonic circular grating. The J-aggregate molecules, as one of the excitonic materials, have unique optical properties, which is an excellent choice for a wide range of optoelectronic applications. In this hybrid system, the J-aggregate thickness and position has important role in exciton-plasmon coupling. For this reason, we consider two different plasmonic hybrid structures as the Au core@shell, and circular grating. Our results illustrate that, the Rabi splitting values for Au core @ J-aggregate layer is calculated to be 118 meV and for the Au core–J-aggregate layer–Au layer rach to 128 meV which is confimes that plexcitonic circular grating shows stronger couplings than the plexcitonic core@shell structure.