News on Plasmonic

News on Plasmonic

In these days, the journal of small science published a new paper entitled as “Switching on Versatility: Recent Advances in Switchable Plasmonic Nanostructures”

Plasmonic nanostructures are emerging as a promising avenue for nanophotonics due to their extreme light and thermal confinement, ultrafast manipulation processes, and potential uses in device miniaturization. However, their fixed functions have limited their versatility in applications. This review provides an overview of recent switchable plasmonic nanostructure engineering techniques, focusing on methods that provide reversible switchability. Passive optical switching, active structure-tunable switching, active material-based switching, and advanced applications, such as multifunctional biomedical sensing, energy harvesting, and dynamic optical devices, are discussed. The specific methods and techniques used to engineer switchable plasmonic nanostructures are also highlighted. By understanding the latest developments and overall trends, this review is expected to help researchers design and fabricate advanced plasmonic nanostructures with unprecedented switch ability and versatility for various applications.

News On Atomic Clock

In these days, the Journal of Applied Physics published a new paper entitled as “An additive-manufactured microwave cavity for a compact cold-atom clock”

ABSTRACT- We present an additive-manufactured microwave cavity for a Ramsey-type, double resonance, compact cold-atom clock. Atoms can be laser cooled inside the cavity using a grating magneto-optic trap with the cavity providing an excellent TE011-like mode while maintaining sufficient optical access for atomic detection. The cavity features a low Q-factor of 360 which conveniently reduces the cavity pulling of the future clock. Despite the potential porosity of the additive-manufacturing process, we demonstrate that the cavity is well-suited for vacuum.
A preliminary clock setup using cold atoms allows for measuring the Zeeman spectrum and Rabi oscillations in the cavity which enables us to infer excellent field uniformity and homogeneity, respectively, across the volume accessed by the cold atoms. Ramsey spectroscopy is demonstrated, indicating that the cavity is suitable for clock applications. Finally, we discuss the limitations of the future clock.

News On Photoacoustic Imaging

In these days, the Journal of Nano Convergence published a new paper entitled as “Functional photoacoustic imaging: from nano‑ and micro‑ to macro‑scale”

Byullee Park, Donghyeon Oh, Jeesu Kim, and Chulhong Kim

Functional photoacoustic imaging is a promising biological imaging technique that offers such unique benefits as scalable resolution and imaging depth, as well as the ability to provide functional information. At nanoscale, photoacoustic imaging has provided super-resolution images of the surface light absorption characteristics of materials and of single organelles in cells. At the microscopic and macroscopic scales. photoacoustic imaging techniques have precisely measured and quantified various physiological parameters, such as oxygen saturation, vessel morphology, blood flow, and the metabolic rate of oxygen, in both human and animal subjects. This comprehensive review provides an overview of functional photoacoustic imaging across multiple scales, from nano to macro, and highlights recent advances in technology developments and applications. Finally, the review surveys the future prospects of functional photoacoustic imaging in the biomedical field.

 New standard atomic vapor cells for Iran by Iranian group and Iranian Technology

Atomic Plasmonic Group

Congratulations for our new paper in JOSAB

Magneto-optical engineering by plasmonic and dielectric metasurfaces in a CoFeB perforated microstructure

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

We have investigated theoretically and experimentally the effect of plasmonic and all-dielectric metasurfaces on the magneto-optical response of the 2D periodic structure. For this purpose, we fabricate polydimethylsiloxane-based 2D microstructures. So, we coated them with a gold layer and a TiO2 dielectric layer as plasmonic and dielectric metasurfaces, respectively, CoFeB as the prominent magneto-optical thin films. We record the spectral magneto optical longitudinal Kerr effect under 40 mT, and the spectrometer’s response in all visible regions. Our results show that the electric and magnetic dipole moments enhance the magneto-optical response by factors of one and two in two closer channels in 650 and 660 nm in an all-dielectric structure, respectively. The plasmonic hot spot-based magneto-optical enhancement is also confirmed in two other media with an enhancement factor of two.

News

In these days, the Journal of Light: Science & Applications published a new paper entitled as “Parameter estimation of the structured illumination pattern based on principal component analysis (PCA): PCA-SIM”

Principal component analysis (PCA), a common dimensionality reduction method, is introduced into SIM to identify the frequency vectors and pattern phases of the illumination pattern with precise subpixel accuracy, fast speed, and noise-robustness, which is promising for real-time and long-term live-cell imaging.

Unlike the video-rate immediate graphics processing unit-accelerated open-source reconstruction (VIGOR) method19, which calibrates the illumination parameters in advance, (e.g., by using the COR algorithm, and then reuses these parameters in the subsequent reconstruction). The successful realization of an instant parameter estimating strategy based on PCA demonstrates the feasibility of real-time SIM reconstruction, providing the potential to significantly improve the live-cell imaging performance of SIM under confined imaging conditions with external disturbances. It can be expected that the performance of the proposed scheme can be further promoted, such as the generalization to three dimensional SIM, combination with regularization based deconvolution techniques20, and so on, pushing
its practicability to a higher level.

News On Magneto-electric Sensors

In these days, the Journal of Nano Energy published a new paper entitled as “Self-powered elementary hybrid magnetoelectric sensor”

There are numerous magnetic field sensors available, but no simple, robust, sensitive sensor for biomedical applications that does not require cryogenic cooling or shielding has yet been developed. In this contribution, a new approach for building a magnetoelectric field sensor is presented, which has the potential to fill this gap. The sensor is based on a resonant cantilever with a piezoelectric readout layer and a pair of opposing permanent magnets. One is attached to the cantilever, and the other one is fixed to a sample holder below. This new concept can be deduced from the most basic composite-based sensor [1], where the magnets interact analog to two particles in a polymer matrix. The bias-free, empirical measurements show a limit-of-detection of 46 pT/√Hz with a sensitivity of 2170 V/T using the sensor’s resonance frequency of 223.5 Hz under ambient conditions. The sensor fabrication is based on low resolution silicon technology, which promises high compatibility and the possibility to be integrated into MEMS devices. The design of this new sensor can be easily altered and adjusted according to the requirements of the specific sensor application. For example, tuning of the operating resonance frequency cannot solely be modified in the production of the cantilever but also by the arrangement of the permanent magnets. In addition, the concept can also be applied to energy harvesters. Beside possible mechanical excitation, the presence of a magnetic stray field alone allows the sensor to convert 20 μT into a power of 1.31 μW/cm3⋅Oe2. The fact that the device does not require any DC bias field makes it very attractive for energy harvesting applications since this allows a purely passive operation. In this manuscript, the sensor assembly, measurements of directional sensitivity, noise level, limit-of-detection, evaluation for energy harvesting applications from magnetic fields and a quantitative sensor model are presented.

News On PC-based Sensors

In these days, the Journal of Plasmonics published a new paper entitled as “Ultrasensitive Photonic Crystal Fiber Sensor for Identifying Various Explosives”

The present work has been performed with an intent of designing a robust, profound, and highly sensitive sensor for numerous explosive detections. The main objective of the present study is to design a simplified structure with fabrication feasibilities. The proposed structure of an explosive detector includes a hollow core surrounded with four sectored-type air holes in the cladding area and silica as background of the fiber which operates for 1–2 THz frequency band. Furthermore, the optical guiding property of the detector is examined, and numerical study has been performed. The modelling has been performed with the help of COMSOL Multiphysics 5.6a software based on finite element method, and Origin 2023 software is used for plotting and analyzing the characteristic curves. The suggested sensor structure has been analyzed for various explosives such as TNT, RDX, HMX, and PETN. Optical parameters such as effective refractive index, confinement loss, effective area, nonlinearity, propagation constant, and relative sensitivity have been evaluated. The proposed structure offers relative sensitivity of 84.02%, 69.42%, 71%, and 79.31% for TNT, RDX, HMX, and PETN samples, respectively. The proposed detector structure offers better sensing proficiency for explosive detection. The simplified design favors the fabrication possibilities and makes it economically effective. The proposed study will add up to the developments in the field of photonics and chemical detection and, moreover, will open new doors for better application for security and explosive sensing.

News On Spintronic

In these days the journal of Photonics Research published a new paper entitled as “Promoting spintronic terahertz radiation via Tamm plasmon coupling”

Spectral fingerprint and terahertz (THz) field-induced carrier dynamics demands the exploration of broadband and intense THz signal sources. Spintronic THz emitters (STEs), with high stability, a low cost, and an ultrabroad bandwidth, have been a hot topic in the field of THz sources. One of the main barriers to their practical application is lack of an STE with strong radiation intensity. Here, through the combination of optical physics and ultrafast photonics, the Tamm plasmon coupling (TPC) facilitating THz radiation is realized between spin THz thin films and photonic crystal structures. Simulation results show that the spectral absorptance can be increased from 36.8% to 94.3% for spin THz thin films with TPC. This coupling with narrowband resonance not only improves the optical-to-spin conversion efficiency, but also guarantees THz transmission with a negligible loss (∼4%) for the photonic crystal structure. According to the simulation, we prepared this structure successfully and experimentally realized a 264% THz radiation enhancement. Furthermore, the spin THz thin films with TPC exhibited invariant absorptivity under different polarization modes of the pump beam and weakening confinement on an obliquely incident pump laser. This approach is easy to implement and offers possibilities to overcome compatibility issues between the optical structure design and low energy consumption for ultrafast THz optospintronics and other similar devices.

Many Congratulations

استاد عزیزمان، سرکارخانم دکتر حمیدی

ریاست محترم آزمایشگاه مگنتوپلاسمونیک

ارتقای شایسته سرکارعالی  به مرتبه استاد تمامی را صمیمانه تبریک گفته وتوفیق روزافزون شما را در جهت پیشبرد واعتلای اهداف آموزشی وپژوهشی پژوهشکده لیزر و پلاسما از درگاه خداوند متعال آرزو میکنیم.

و من الله توفیق

اعضای آزمایشگاه مگنتوپلاسمونیک