congratulation to Our new paper in Journal of Thin solid films

Thermoplasmonic enhanced detection efficiency by gold nanoparticles/ chlorophyll heterojunction on silicon nanowires

S. Valimohammadi, S. M. Hamidi and L. Rajaee

https://doi.org/10.1016/j.tsf.2025.140837

Abstract:
This study presents the development of a ternary heterojunction nanostructure for visible-light detection at 532 nm. Silicon nanowires (SiNWs) were grown using the metal-assisted chemical etching (MACE) method. The structure incorporates gold nanoparticles (Au NPs), synthesized via laser ablation (a fixed amount of S₀: 1500 µL), which were combined with varying concentrations of chlorophyll-a (Chl-a) (S₁: 1000 µL, S₂: 1500 µL, S₃: 2000 µL). Characterization techniques included SEM and AFM to confirm SiNWs morphology, UV-Vis spectroscopy to examine the optical properties of the Au/Chl-a combination, and current-voltage (I-V) measurements to evaluate the enhanced photodetector performance. Key findings demonstrated that plasmon-exciton dipole interactions effectively increase electron-hole pair separation via the formation of plexcitons. Furthermore, thermoplasmonic heating raised the temperature of the optimal sample (SiNWs@S₂) to 51.6°C (compared to the baseline SiNWs@S₀ temperature of 40.7°C), representing a 26.78% improvement. This system shows promising potential for high-performance optical sensing applications.

Figure 2: (a-c) Cross sectional scanning electron microscopy (SEM) micrographs of SiNWs fabricated at 30 min etching time in HF (40%)/AgNO3 (0.1 M)/H2O2(30%) solutions having a volume ratio of: 16:5:60 (top row),(d) 2D AFM image of SiNW,(e)Height profile and slope (f) I-V curve of P-type silicon wafers and SiNW at different voltages.

Multi-parameter microwave quantum sensing with a single atomic probe

Zhigang Feng, Xiaochi Liu, Zhenfei Song & Jifeng Qu

https://doi.org/10.1038/s41598-025-89697-4

Scientic Reports

Abstract:

We demonstrate a multi-parameter sensing scheme for free space microwave electric and magnetic elds in single vapor cell based on the atom-based microwave detection techniques. A weak probe laser though a rubidium vapor cell rst acts as magnetic probe to measure the microwave magnetic eld via atomic Rabi resonance of the ground state hyperne transition. When another strong coupling laser is subsequently counter-propagated and overlapped with the probe laser in the same atomic vapor cell, the probe laser is then used as electric probe to measure microwave electric eld by o – resonant microwave dressed Rydberg Autler–Townes splitting. We achieve measurement of microwave electric and magnetic elds without any complicated tuning methods at the clock frequency of 6.835 GHz. Based on the inherent relationship between microwave electric and magnetic elds, and their good linear response characteristics in respective suitable power ranges, the equivalent microwave magnetic elds are derived from linear tting of the measured electric elds, which are in agreement with the calibrated experimental results within the same power range. This work provides an eective approach for extending the power dynamic range of atom-based microwave quantum sensors.

Fig. 1. (a ) The relevant energy levels diagram for 87Rb atoms. (b) Schematic of the experimental setup. DMdichroic mirror, HWP half-wave plate, BPD balanced photodetector, HRM high re?ection mirror, DB beam displacers.

Temporal Coding of Incident Light on Phase‑Change Plasmonic Surfaces for Adaptive Optical Memory Storage

Viyat Varun Updhay· N. Nagabhooshanam · Sharad Rathore · Madan Lal. A. C. Santha Sheela6 · D. Beulah· A. Rajaram

https://doi.org/10.1007/s11468-025-03218-7

The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2025

Abstract
A recongur able phase-change photonic platform is demonstrated that combines Ge2Sb2Te5 (GST) with plasmonic bowtie nanoantennas, which can achieve sub-nanosecond, multi-level optical memory and logic operations. Sputtered GST lms as thin as 20–50 nm were found to be exceedingly uniform, with root-mean-square (RMS) roughness of 0.45–0.65 nm, comparable to the best standards. Gold nanoantennas with sub-10 nm resolution were fabricated by high-precision electron beam lithography to guarantee maximum light connement. Localized sur face plasmon resonances (LSPR) were switched between 825 and 1525 nm, and simulations indicated electric eld enhancements of | E/E 0|= 18.2 × . Excitation with femtosecond pulses produced phase transitions at a uence t hreshold of 0.18 µJ/µm 2 (crystallization) and temperatures above 850 K (amorphization), and the reect ance modulation was measured to be as large as 35%. The refractive index (n) and extinction coecient ( k) ranged between 3.8 and 6.6 and 0.12 to 2.5, respectively, and electrical conductivity changed by ~ 104-fold across phase transitions. Localized peak temperatures of ~ 465 K were predicted by COMSOL simulations, and ultrafast, interface-controlled kinetics were suggested by Avrami exponents (1.925) in good agreement with molecular dynamics calculations, and crystallization times were found to be between 180 and 250 ps. Memory mapping showed four stable reect ance levels with > 8% spacing and > 10,000 cycle endurance. Photonic logic gates (AND, OR and XOR) were achieved, which demonstrated sub-ns switching and improved non-volatility. The platform enables scalable, high-speed optoelectronic control of next-generation memory and computing systems.

PCM layerFig. 1 Plasmonic nanoantenna-induced nanoscale phase switching in

High-contrast nonlinear spiral phase contrast imaging via four-wave mixing in atomic medium

WEI GAO,SANDAN WANG, JINPENG YUAN,LIRONGWANG,LIANTUAN XIAO, AND SUOTANG JIA

https://doi.org/10.1364/OE.572157

Journal 2025

Abstract: Nonlinearspiralphasecontrastimagingservesasapowerfultoolforhigh-performance image edge detection in optical imaging. Compared to conventional computer-based digital imaging methods, it oers numerous possibilities for optical image processing with superior speed, lower energy consumption, and high information capacity. Here, we experimentally demonstrate the high-contrast nonlinear spiral phase contrast imaging in a diamond-type atomic system. A pump vortex-ltered beam (780 nm) and a signal beam with object image (776 nm) simultaneously interact with Rb atomic medium. As a result, a 420 nm beam is generated via the nonlinear four-wave mixing process, carrying the edge information of asymmetric Arabic numeral patterns. The geometric patterns such as triangle, circle, and square are further utilized to validate the eectiv eness of nonlinear spiral phase contrast imaging. The high image contrast of ∼ 95.8%
is achieved owing to the stringent phase matching conditions via the atomic four-wave mixing process. Moreover, the directional nonlinear spiral phase contrast imaging of circle and square patterns at 420 nm are realized by employing a Laguerre-Gaussian composite vortex lter on the 780 nm pump beam. This work establishes a versatile platform for multi-wavelength optical image analysis and provides a robust foundation for developing optical information processing methods.

Fig. 1. (a) The diamond-type energy level conguration of Rb atoms. (b) Principle of the nonlinear SPC imaging via four-wave mixing in Rb vapor. (c) Sketch of the experimental setup. M, mirror; HWP, half-wave plate; PBS, polarization beam splitter; SLM, spatial light modulator; L, lens; A, aperture; BS, beam splitter; F, bandpass lter .

Rydberg electromagnetically induced85transparency of Rb vapor in Ar, Ne, and N gases

Bineet Dash,Nithiwadee Thaicharoen,Eric Paradis,Alisher Duspayev,and Georg Raithel

https://doi.org/10.1063/5.0237759

APL Quantum 2, 016132 (2025)

ABSTRACT
An experimental study on Rydberg electromagnetically induced transparency (EIT) in rubidium (Rb) vapor cells containing inert gases at pressures ≤5 Torr is reported. Using an inert-gas-free Rb vapor cell as a reference, we measure frequency shift and line broadening of the EIT spectra in Rb vapor cells with argon, neon, or nitrogen gases at pressures ranging from a few mTorr to 5 Torr. The results qualitatively 18 October 2025 11:50:48
agree with a pseudo-potential model that includes s-wave scattering between the Rydberg electron and the inert-gas atoms and the effect of polarization of the inert-gas atoms by the Rydberg atoms. Our results are important for establishing Rydberg-EIT as an all-optical and non-intrusive spectroscopic probe for eld diagnostics in low-pressure radio frequency discharges.

FIG. 1. (a) Energy levels of 85Rb used in our experiment. The probe laser (λp = 780 nm) is locked to the 5S1/2,
F = 3 ↔ 5P3/2, F′ = 4 resonance, and the coupling laser is scanned across the5P3/2 ↔ 36D5/2 transition.(b)Experimental setup. Some elements are omitted for simplicity.

Dual-Parameter Surface Plasmon Resonance Photonic Crystal Fiber Sensor for Simultaneous Magnetic Field and Temperature Detection with Potential SERS Applications

by Haoran Wang ,Shiwei Liu,Wenzhao Liu and Shuai Wang 

https://doi.org/10.3390/photonics12040355

This article belongs to the Special Issue Research, Development and Application of Raman Scattering Technology

Abstract

A high-sensitivity surface plasmon resonance (SPR) dual-parameter sensor based on photonic crystal fiber (PCF) is proposed for simultaneous measurement of magnetic field and temperature. The grooves on the right and upper sides of the PCF, serving as distinct detection channels, are filled with magnetic fluid and polydimethylsiloxane, respectively, enabling high-sensitivity detection of magnetic field and temperature. The structure parameters and sensing characteristics of the proposed sensor are investigated based on the finite element method. Numerical results indicate, within the wavelength range of 850–1050 nm, that the sensor achieves a high magnetic field sensitivity of 86 pm/Gs under x-polarization in the range of 100–600 Gs, and exhibits a temperature sensitivity of −2.63 nm/°C under y-polarization within the temperature range of 20–40 °C. Furthermore, the detection precision and applicability of the sensor in actual measurement applications could be further enhanced in the future by introducing surface-enhanced Raman scattering technology.

Figure . Schematic illustration of the cross-sectional view of the proposed dual-channel SPR-PCF sensor.

پیام تسلیت

سرکار خانم عابدی عزیز با نهایت تأسف و تأثر ضایعه در گذشت پدربزرگ گرامی‌تان را خدمت شما و خانواده محترم تسلیت عرض می‌کنیم. بقای عمر با عزت برای شما و همچنین رحمت واسعه برای آن مرحوم را از خداوند متعال خواستاریم

Cavity-enhanced solid-state nuclear spin gyroscope

Hanfeng Wang, Shuang Wu, Kurt Jacobs, Yuqin Duan, Dirk R Englund, Matthew E Trusheim

1. Massachusetts Institute of Technology, 50 Vassar Street, Cambridge, MA 02139, USA
2. Honda Research Institute USA, Inc., San Jose, CA 95134, USA
3. U.S. Army DEVCOM Army Research Laboratory, Adelphi, MD 20783, USA
4. Department of Physics, University of Massachusetts Boston, Boston, MA 02125, USA

Physical Review Letters 134 (18), 183603, 2025

https://doi.org/10.48550/arXiv.2502.01769

Solid-state quantum sensors based on ensembles of nitrogen-vacancy (NV) centers in diamond have emerged as powerful tools for precise sensing applications. Nuclear spin sensors are particularly well suited for applications requiring long coherence times, such as inertial sensing, but remain underexplored due to control complexity and limited optical readout efficiency. In this work, we propose cooperative cavity quantum electrodynamic (cQED) coupling to achieve efficient nuclear spin readout. Unlike previous cQED methods used to enhance electron spin readout, here we employ two-field interference in the NV hyperfine subspace to directly probe the nuclear spin transitions. We model the nuclear spin NV-cQED system (nNV-cQED) and observe several distinct regimes, including electromagnetically induced transparency, masing without inversion, and oscillatory behavior. We then evaluate the nNV-cQED system as an inertial sensor, indicating a rotation sensitivity improved by 3 orders of magnitude compared to previous solid-state spin demonstrations. Furthermore, we show that the NV electron spin can be simultaneously used as a comagnetometer, and the four crystallographic axes of NVs can be employed for vector resolution in a single nNV-cQED system. These results showcase the applications of two-field interference using the nNV-cQED platform, providing critical insights into the manipulation and control of quantum states in hybrid NV systems and unlocking new possibilities for high-performance quantum sensing.

FIG. 1. Two-eld interference in nNV-cQED. (a) Top: NV crystal structure. Bottom: diamond with NVs rotates with rate R = {Rx, Ry , Rz }. (b) NV energy level structure. The transition |1⟩ ↔ |e⟩ is coupled to the cavity mode for the cavity-enhanced readout. A driving eld Ω2 is applied between the spin-exchanging transition |2⟩ ↔ |e⟩. (c) Hybrid system with a microwave resonator and an NV spin ensemble. A green laser is applied to continuously polarize the NV spin to the |ms = 0⟩, and a detection loop is incorporated to measure the re ection signal from the resonator. (d) |α0|2 as a function of detuning ∆/κ within strong coupling regime. An EIT feature appears around the resonant frequency. (e) Top: Im(σ1e) as a function of Ω2. The EIT (MWI) regime features a negative (positive) Im(σ1e). Bottom: Time dynamics of Im(α). (f) α0 as a function of P and Ω2. The solid line indicates the perfect EIT condition. The boundary of the oscillation regime is marked as a white line.

congratulation to Our new paper in Journal of Optic

Temperature Dependent Random Laser Performance of Au@Cu and Cu@Au Core-Shell Nanoparticles in a Rhodamine 6G–PNIPAM Smart Polymer Matrix Medium

Mariam Kadhim Jawad, J. M. Jassim, S. F. Haddawi, S. M. Hamidi

Abstract:
This study aimed to investigate the temperature-dependent performance of random lasers using Rhodamine 6G (R6G) dye embedded in a thermoresponsive PNIPAM polymer matrix with Au, Cu, Au@Cu, and Cu@Au nanoparticles serving as scattering centers. At 25 °C, only fluorescence was observed due to the hydrophilic state of PNIPAM, resulting in high optical absorption and insufficient refractive index contrast for lasing. As temperature increased to 30–45 °C, PNIPAM became hydrophobic, enhancing index contrast and reducing absorption, which facilitated random lasing. Among the nanoparticles, Au showed the highest emission intensity (62618 a.u.) and narrowest FWHM (4.6 nm), followed by Cu@Au (59908 a.u., 5.3 nm), attributed to the strong plasmonic response of the Au shell. Conversely, Au@Cu and Cu exhibited weaker outputs due to higher damping and less effective plasmonic resonance. Temperature-dependent spectral analysis showed that Cu had the most pronounced bandwidth narrowing (7.5 nm to 3.4 nm), while Au@Cu demonstrated the highest intensity modulation (30913 a.u. to 65195 a.u.). A temperature-induced blue shift in peak emission was observed, most prominently in PNIPAM alone (6.2 nm), with smaller shifts in nanocomposite systems due to varied thermal coupling. These results highlight the pivotal role of PNIPAM’s thermal transition in controlling random laser behavior, offering new strategies for designing tunable or thermally stable laser systems.

Long-range hyperbolic polaritons on a non-hyperbolic crystal surface

Lu Liu, Langlang Xiong, Chongwu Wang, Yihua Bai, Weiliang Ma3, Yupeng Wang1, Peining Li, Guogang Li, Qi Jie Wang, Francisco J. Garcia-Vidal, Zhigao Dai & Guangwei Hu

Nature,Springer Nature

https://doi.org/10.1038/s41586-025-09288-1

Abstract:

Hybridized matter–photon excitations in hyperbolic crystals—anisotropic materials characterized by permittivity tensor components with opposite sign—have attracted substantial attention owing to their strong light–matter interactions in the form of hyperbolic polaritons. However, these phenomena have been restricted to hyperbolic crystals, whose optical responses are confined to fixed spectral regions and lack tunability, thereby limiting their broader applicability. Here we demonstrate the emergence of hyperbolic surface phonon polaritons in a non-hyperbolic yttrium vanadate (YVO₄) crystal. Using real-space nanoimaging combined with theoretical analyses, we visualize hyperbolic wavefronts of surface phonon polaritons on YVO₄ crystal surfaces within its non-hyperbolic frequency range, where the permittivity tensor components of the material have the same negative sign. Furthermore, by varying the temperature from room temperature to cryogenic levels, we realize in situ manipulation of polariton dispersions, enabling a topological transition from hyperbolic to canalization and eventually to the elliptic regime. This temperature-controlled dispersion engineering not only provides precise control over polariton topology but also modulates their wavelength and group velocity, showing remarkable sensitivity alongside low-loss, long-range propagation. These findings extend the realm of hyperbolic nano-optics by removing the reliance on hyperbolic crystals, unlocking opportunities for applications in negative refraction, superlensing, polaritonic chemistry ntegrated photonics and beyond.