congratulation to Dear Dr Zahraa for her PhD defense
The research focus on the design and investagation of reconfigrable metasurface based graphene optical antennas for beam steering and beam focusing applications
congratulation for our new paper:Plasmonic smart contact lens based on etalon nanostructure for tear glucose sensing
Journal of scientific reports
N. Roostaei & S. M. Hamidi
Smart contact lenses, one of the most advanced wearable platforms, offer a combination of optical and electronic technologies that provide exceptional capabilities in various fields. These lenses are equipped with biosensors, microchips, and sometimes even miniature displays that enable the collection and analysis of biological and environmental data. Smart contact lenses represent a big leap in wearable technology and biosensors, potentially providing a new future for human interaction with the digital world, improving personal health, and promising a hopeful future in vision and wearable technologies. In this study, smart contact lenses based on plasmonic etalon nanostructure have been proposed and fabricated for tear glucose sensing. A cost-effective and simple technique of soft nanolithography has been proposed to fabricate a plasmonic sensor chip on a contact lens, enabling the detection of glucose solutions at different concentrations of 0.15, 1.5, 5, and 10 mM in a phosphate-buffered saline (PBS) solution. The proposed plasmonic etalon-based smart contact lens as a wearable platform exhibits the capacity to sense tear glucose (even at low concentration values) and offers relatively high sensitivity for non-invasive tear glucose sensing applications. The biocompatibility, cost-effectiveness, stability, and simple production of these contact lenses may provide new perspectives on wearable biosensors.
Plasmonic Ring Resonator‑Based Sensors: Design, Performance, and Applications
Plasmonics
https://doi.org/10.1007/s11468-025-02890-z
REVIEW ، The Author(s) 2025
C. S. Mallika · M. Shwetha
Plasmonic ring resonators have emerged as a powerful platform for high sensitivity, small footprint, and versatility across various applications when compared to traditional optical sensors. In this review, the key design principles, performance characteristics through geometrical tuning, material selection, and challenges across multiple sensing applications of plasmonic ring resonator are discussed. Research to improve their design capabilities to get real-time results with minimal sample preparation underscores the signicant im pact of plasmonic ring resonator on future sensing technologies. By exploiting the resonant behavior and the strong eld connement of sur face plasmon polaritons, they can achieve high sensitivity and compact footprints, attracting them for various sensing applications, particularly for biological and chemical sensing applications. Moreover, with ongoing advancements in fabrication techniques, nanophotonics, and material science, the potential applications of sensing technology have surpassed beyond expectations. However, the challenges like fabrication complexity, eectiv e coupling methods, material losses environmental impact on sensor performance, and precision alignment while integrating plasmonic components with ring resonators are addressed and the possible solutions are discussed for the future investigation.
a: Working principle of SPR and b: LSPR
congratulation for our new paper:Magneto-optical Kerr effect in Metasurface Flexible Microarrays by near field excitation
Journal of theoretical and applied physics
N. S. Shnan, N. Roostaei, S. M. Hamidi, V. I. Belotelov, A. I. Chernov
We have experimentally examined the effect of light localization and near field effect on the magneto-optical response of the two-dimensional coupled micro-ring periodic structure. For this purpose, we fabricated main template by laser writing system and stamped it by polydimethylsiloxane-to reach the main two-dimensional microstructures. Thus, we coated them with a gold layer and Ni layer as plasmonic and magnetic metasurfaces, respectively. We recorded the spectral magneto-optical longitudinal Kerr effect under 200 mT and the spectrometer’s response in all visible regions under the normal condition as well as pump and probe system by the aid of green laser as pump. The pump was done via high numerical aperture objective lens to excite near field of plasmon in a two-dimensional structure. Our results indicate that the localized surface plasmon resonance, surface lattice resonance as well as electric and magnetic dipole moments enhance the magneto-optical response in two closer channels in the middle of visible region.
A photonic crystal receiver for Rydberg atom-based sensing
Hadi Amarloo, Mohammad Noaman, Su-Peng Yu, Donald Booth, Somayeh Mirzaee, Rajesh Pandiyan, Florian Christaller, James P. Shaffer
Rydberg atom-based sensors use atoms dressed by lasers to detect and measure radio frequency electromagnetic fields. The absorptive properties of the atomic gas, configured as a Rydberg atom-based sensor, change in the presence of a radio frequency electromagnetic field. While these sensors are reasonably sensitive, the best conventional radio frequency sensors still outperform Rydberg atom-based sensors with respect to sensitivity. One approach to increase the sensitivity of Rydberg atom-based sensors is to engineer the vapor cell that contains the atomic gas. In this work, we introduce a passive, all-dielectric amplifier integrated into a Rydberg atom-based sensor vapor cell. The vapor cell is a combination of a slot waveguide and a photonic crystal. The structural features of the vapor cell yield a power amplification of ~24 dB. The radio frequency electromagnetic field is coupled adiabatically into the slot waveguide and slowed to increase the interaction between the radio frequency field and the atoms to effectively amplify the incoming signal, i.e., increase the Rabi frequency on the radio frequency transition. The work shows the utility of vapor cell engineering for atom-based quantum technologies and paves the way for other such devices.
Fig. Photonic crystal vapor cell with slot region
filled with Cs atoms, and taper structure for mode
conversion of the incoming free space RF
electromagnetic wave. The holes are organized to
produce a photonic crystal that slows an RF elec-
tromagnetic wave propagating along the x axis
around a specific frequency. The slot is hermetically
sealed with glass on both sides and filled with Cs
atoms. The device uses a thermally activated getter
source to load the Cs atoms, shown as the disc in the
circular pocket separated from, but fluidly coupled
to the slot. Light is coupled in along the z axis after
being combined using beam splitters (BS) and
expanded using cylindrical lenses. The light is
detected using a photodiode (PD). A piece of glass
Parallel to the vapor cell is used to tune the frequency
of the resonance.
A novel approach in cancer diagnosis: integrating holography microscopic medical imaging and deep learning techniques—challenges and future trends
Asifa Nazir, Ahsan Hussain, Mandeep Singh, Assif Assad
Biomedical Physics & Engineering Express 11 (2), 022002, 2025
Medical imaging is pivotal in early disease diagnosis, providing essential insights that enable timely and accurate detection of health anomalies. Traditional imaging techniques, such as Magnetic Resonance Imaging (MRI), Computer Tomography (CT), ultrasound, and Positron Emission Tomography (PET), offer vital insights into three-dimensional structures but frequently fall short of delivering a comprehensive and detailed anatomical analysis, capturing only amplitude details. Three-dimensional holography microscopic medical imaging provides a promising solution by capturing the amplitude (brightness) and phase (structural information) details of biological structures. In this study, we investigate the novel collaborative potential of Deep Learning (DL) and holography microscopic phase imaging for cancer diagnosis. The study comprehensively examines existing literature, analyzes advancements, identifies research gaps, and proposes future research directions in cancer diagnosis through the integrated Quantitative Phase Imaging (QPI) and DL methodology. This novel approach addresses a critical limitation of traditional imaging by capturing detailed structural information, paving the way for more accurate diagnostics. The proposed approach comprises tissue sample collection, holographic image scanning, preprocessing in case of imbalanced datasets, and training on annotated datasets using DL architectures like U-Net and Vision Transformer (ViT’s). Furthermore, sophisticated concepts in DL, like the incorporation of Explainable AI (XAI) techniques, are suggested for comprehensive disease diagnosis and identification. The study thoroughly investigates the advantages of integrating holography imaging and DL for precise cancer diagnosis. Additionally, meticulous insights are presented by identifying the challenges associated with this integration methodology.
New optical memory unit poised to improve processing speed and efficiency
Fast, versatile volatile photonic memory could enhance AI, sensing and other computationally intense applications
F. Ashtiani, “Programmable photonic latch memory,” Opt. Express, 33, 3501-3510 (2025).
WASHINGTON — Researchers have developed a new type of optical memory called a programmable photonic latch that is fast and scalable. This fundamental memory unit enables temporary data storage in optical processing systems, offering a high-speed solution for volatile memory using silicon photonics.The new integrated photonic latch is modeled after a set-reset latch, a basic memory device used in electronic devices to store a single bit by switching between set (1) and reset (0) states based on inputs.“While optical communications and computing have seen significant progress over the past decades, data storage has been predominantly implemented using electronic memory,” said the study’s author Farshid Ashtiani from Nokia Bell Labs. “Having a fast optical memory that can be used with optical processing systems, as well as other optical systems used in communications or sensing, would make them more efficient in terms of energy and throughput.”In the Optica Publishing Group journal optics express, the researchers describe a proof-of-concept experiment in which they demonstrated the photonic latch using a programmable silicon photonic platform. Features such as optical set and reset, complementary outputs, scalability and compatibility with wavelength division multiplexing (WDM) make this approach promising for faster and more efficient optical processing systems.“Large language models like ChatGPT rely on massive amounts of simple mathematical operations, such as multiplication and addition, performed iteratively to learn and generate answers,” said Ashtiani. “Our memory technology could store and retrieve data for such systems at high speeds, enabling much faster operations. While a commercial optical computer is still a distant goal, our high-speed optical memory technology is a step toward this future.”
Advancing integrated optical memory
Optical technologies have been instrumental in advancing communication systems, from long-haul data transmission and data center connectivity to emerging technologies like optical interconnects and computing. However, data storage remains predominantly electronic due to its scalability, compactness and cost-effectiveness. This presents challenges for optical processing systems because transferring optical data to electronic memory — and back — increases energy consumption and introduces latency. Although there has been extensive research in the area of optical memory, most implementations rely on bulky, costly and energy-intensive setups or specialized materials that are not typically offered in commercially available silicon photonic processes, leading to higher costs and lower yields. To overcome these challenges, the researchers created an integrated programmable photonic latch based on optical universal logic gates using silicon photonic micro-ring modulators. These devices can be implemented in commercially available silicon photonic chip fabrication processes. They combined two optical universal logic gates to create an optical latch that can hold optical data.
Creating memory that is scalable and fast
Ashtiani says that one key advantage of the new system is its scalability. “Because each memory unit has an independent input light source, it is possible to have several memory units working independently without affecting each other through optical power loss propagation,” he said. “The memory units can also be co-designed with the existing silicon photonic systems and be built reliably and with very high yields.” Another advantage is the photonic memory unit’s wavelength selectivity, which allows it to work seamlessly with WDM. This is because the unit’s micro-ring modulators are designed to operate at specific wavelengths, enabling multi-bit data storage within a single memory unit. Additionally, it enables fast memory response time, measured in tens of picoseconds, outpacing the clock speeds of advanced digital systems and supporting high-speed optical data storage.To demonstrate this approach to optical memory before making dedicated chips, the researchers used a programmable photonic platform to implement the universal logic gates and the optical latch through experiments and realistic simulations. The researchers tested the gates under different input scenarios. Even in the presence of random variations, the gates reliably generated the desired outputs. Similarly, the latch also performed all functions — set, reset, hold — accurately in the presence of input power variations.Next, the researchers would like to pursue several research directions to make the new memory units more practical. This includes scaling the technology to a larger number of memory units and fabricating dedicated photonic memory chips. This, combined with the WDM compatibility, would enable higher on-chip photonic memory density. They would also like to develop a way to use a single manufacturing process to integrate both the photonic memory circuit and the electronics needed to control it.
Caption: This new type of optical memory unit, called a programmable photonic latch, is fast and scalable. It could offer a high-speed silicon photonics solution for volatile memory.
Credit: Farshid Ashtiani, Nokia Bell Labs
Congratulation for our new paper in SREP
Magnetic nanoparticles of
Nd2Fe14B prepared by ethanol assisted wet ball milling technique
Younes Mehrifar, Hamed Moqtaderi, Seyedeh Mehri Hamidi, FaridehGolbabaei, Mahdi Hasanzadeh & Somayeh Farhang Dehghan
The magnetic material Nd2Fe14B is one of the strongest magnetic materials found in nature. The
demand for the production of these nanoparticles is significantly high due to their exceptional
properties. The aim of the present study is to synthesize magnetic nanoparticles of Nd2Fe14B using
ethanol in the wet ball milling technique (WBMT). Nd2Fe14B powder an average particle size(APS)
of 730 nm was subjected to wet ball milling in stainless steel cup containing 5 mm diameter steel
balls.The powder was milled for 12 h at 400 rpm, with intervals of 15 min and a 15-second pause
each time. The morphology of the powder and nanoparticles, crystallinity, changes of the samples
under temperature, magnetic properties, and the structural bonds were analyzed using field
emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), thermogravimetric analysis
(TGA), vibrating sample magnetometry (VSM), and Fourier-transform infrared spectroscopy (FTIR).
The microstructural images revealed that the shape of the particles changed from flat(730 nm) to
spherical(76 nm) after WBMT. The crystallinity results indicated a hexagonal crystal structure, with the
average crystallite size being 17.1 nm. In the spectrum of the synthesized Nd2Fe14B nanoparticles,
a peak appeared at a wavenumber of 803 cm−1, along with peaks at wavenumbers of 1037 cm−1 and
1083 cm−1, which are associated with the stretching vibrations of Nd-Fe, Fe-B, and Nd-B bonds,
respectively. Numerical results of magnetic performance parameters indicated the ferromagnetic
properties of the particles(HC=6097.47, Mr=34.65 and MS=49.11).It appears that in WBMT, the
operational parameters significantly affect the average crystallite size, saturation magnetization, as
well as the size and shape of the nanoparticles. Additionally, the ferromagnetic nature of Nd2Fe14B in
the hysteresis loop plays an important role in the thermal stability of the nanoparticles.
Congratulations for our new paper in sensors and actuators A
Magneto-plasmonic response of nickel nano-rings prepared by
electroless method
Akram Poursharif, Peyman Sahebsar, Seyyed Mahmood Monirvaghefi, Seyedeh Mehri Hamidi, Mahshid Kharaziha, Masih Bagheri
Over recent years, there has been increasing interest in the development of magneto-plasmonic nanostructures for advanced sensing applications, many of which have been produced using various lithography and sputtering deposition techniques. This research examines the magneto-plasmonic properties of nickel nano-rings with diameters between 200 and 600 nm, aimed at applications in sensing technologies. Nickel-silver-boron (Ni-Ag-B) nanoarrays were fabricated on ITO substrates through a combination of nano-sphere lithography and selective electroless deposition in a Ni-B and silver nanoparticle bath. Compared to conventional methods, this fabrication process is simpler, more cost-efficient, and produces durable coatings due to the formation of strong covalent bonds. Additionally, the electroless method generally leads to the formation of uniform coatings on complex surfaces. The distinct shape of the nano-rings enhances plasmonic effects by generating a highly concentrated electromagnetic field, outperforming other nanostructures. Unlike thin films, light reflectivity tests showed that the nano-rings exhibited surface plasmon resonance (SPR) in the 470-614 nm range at a 45° incident angle. In the next step, ellipsometry parameters were calculated. To further investigate the nano-rings’ effect, focus on the effective ellipsometry parameters. Additionally, Magneto-Optical Kerr Effect (MOKE) measurements revealed narrow Full Width at Half Maximum (FWHM) peaks at 512 nm and 560 nm, demonstrating their strong potential for highly sensitive detection compared to conventional SPR and ellipsometry-SPR. Finite element simulations using COMSOL further explored how magnetic fields influence the electromagnetic response of the nickel nano-rings, revealing promising applications in optical communication and sensing technologies.
