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        <title>Frontiers in Physics | Optics and Photonics section | New and Recent Articles</title>
        <link>https://www.frontiersin.org/journals/physics/sections/optics-and-photonics</link>
        <description>RSS Feed for Optics and Photonics section in the Frontiers in Physics journal | New and Recent Articles</description>
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        <pubDate>2026-05-13T15:11:17.899+00:00</pubDate>
        <ttl>60</ttl>
        <item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fphy.2026.1811376</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fphy.2026.1811376</link>
        <title><![CDATA[Wave structures and chaotic behaviors of perturbed nonlinear Biswas-Milovic equation with Kudryashov’s law of refractive index]]></title>
        <pubdate>2026-05-07T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Yuxi Zhang</author>
        <description><![CDATA[Nonlinear partial differential equations provide a fundamental mathematical framework for understanding the real world. This study presents a comprehensive analysis of perturbed nonlinear Biswas-Milovic equation with Kudryashov’s law of refractive index. By employing the traveling wave transformation, the original partial differential equation is first converted into a nonlinear ordinary differential equation. The Gaussian soliton solutions are then derived via the generalized trial equation method. To obtain its qualitative properties, a two-dimensional dynamic system is constructed accordingly. Subsequently, we establish the existence of periodic, kink and antikink soliton, and bell-shaped soliton solutions in the qualitative analysis. In particular, we obtained all traveling wave solutions to the equation in the quantitative analysis. Moreover, the exploration of chaotic dynamics is conducted by introducing specific perturbation terms, thereby revealing chaotic behaviors. To the best of our knowledge, this work is the first to provide a classification of possible traveling wave solutions to this equation and to show its chaotic properties.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fphy.2026.1856933</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fphy.2026.1856933</link>
        <title><![CDATA[Editorial: Advanced high power solid-state laser technology, volume II]]></title>
        <pubdate>2026-05-06T00:00:00Z</pubdate>
        <category>Editorial</category>
        <author>Rumao Tao</author><author>Oleg Antipov</author><author>Pengfei Ma</author><author>Haotong Ma</author>
        <description></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fphy.2026.1814739</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fphy.2026.1814739</link>
        <title><![CDATA[High-sensitivity laser heterodyne radiometer based on balanced detection technology]]></title>
        <pubdate>2026-04-30T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Renshi Li</author><author>Hao Deng</author><author>Chenguang Yang</author><author>Tao Sun</author><author>Zhenyu Xu</author><author>Nailiang Cao</author><author>Ruifeng Kan</author>
        <description><![CDATA[A heterodyne radiometer (LHR) based on the balanced-detection method has been developed to evaluate system performance under both balanced-detection and single-channel-detection modes. Experimental results demonstrate that the balanced-detection LHR exhibits superior suppression of laser-induced noise compared to the traditional single-channel-detection LHR. The developed system achieved a noise equivalent power (NEP) of 2.53 × 10−15 W/√Hz, which is only 1.7 times of the theoretical quantum limit. To further assess system performance, measurements of atmospheric carbon dioxide (CO2) column abundance were conducted. The measurement precision of the balanced-detection LHR was determined to be approximately 0.6%, which is 5.67 times higher than that of the single-channel-detection LHR.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fphy.2026.1849264</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fphy.2026.1849264</link>
        <title><![CDATA[Editorial: Acquisition and application of multimodal sensing information, volume III]]></title>
        <pubdate>2026-04-28T00:00:00Z</pubdate>
        <category>Editorial</category>
        <author>Xukun Yin</author><author>Changhui Jiang</author><author>Huadan Zheng</author><author>Angelo Sampaolo</author><author>Kaijie Xu</author>
        <description></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fphy.2026.1798812</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fphy.2026.1798812</link>
        <title><![CDATA[Influence of laser amplitude and beam waist radius on attosecond pulse trains in a cross-collision tightly focused circularly polarized field]]></title>
        <pubdate>2026-04-22T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Zihan Li</author><author>Zichen Xue</author><author>Zhaoze Chai</author><author>Bo Chen</author><author>Youwei Tian</author>
        <description><![CDATA[Radiation from nonlinear Thomson scattering (RNTS) has emerged as an important mechanism for generating highly directional and broadband attosecond emission. However, the influence of laser-field structure on electron dynamics and the resulting radiation characteristics has not yet been systematically explored. In this work, we employ a tightly focused circularly polarized Gaussian laser model that incorporates high-order field components to investigate the trajectory evolution and radiation features of high-energy electrons in a cross-collision geometry under the coupled variation of laser amplitude a0  (normalized laser amplitude a0)and beam waist radius b0normalized beam waist b0=ω0/λ0. The results show that a0 predominantly governs longitudinal acceleration and spectral broadening, while b0 modulates the interaction length and strongly affects radiation directivity. Together, these parameters determine the spatial peak position, beam collimation, and structural features of the emitted attosecond pulses. This study reveals the regulatory role of laser-field structure in RNTS and provides theoretical guidance for optimizing high-directionality and broadband attosecond light sources.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fphy.2026.1799778</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fphy.2026.1799778</link>
        <title><![CDATA[A novel metasurface structure for oblique incidence absorption and ultrawideband transmission based on Haxagonal metal rings and epoxy laminate]]></title>
        <pubdate>2026-04-10T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Heba G. Mohamed</author><author>Darius Anriukaitis</author><author>Jaromir Konecny</author><author>Mohd Aliff Sani</author><author>Hung Tran-Huy</author><author>Anh Nguyen-Quang</author><author>Iyas Qaddara</author><author>Michal Prauzek</author>
        <description><![CDATA[IntroductionMetamaterials progressed greatly due to groundbreaking studies on composite media that show both negative permeability and permittivity at the same time. This study has significantly improved our understanding of materials that can surpass the electromagnetic properties of standard substances, thereby transcending the constraints imposed by their intrinsic electromagnetic features. They have attracted considerable interest owing to their remarkable ability to manipulate EM waves through subwavelength structures organized in precise configurations. These materials are famous for their unique electromagnetic characteristics, such as negative index refraction, super-resolution imaging, and perfect absorption. The effective characteristics of metamaterials can be tailored to fulfill particular application needs—like obtaining negative permittivity and permeability—by adjusting the dimensions of a unit cell. With the EM environment becoming more complex, challenges to EM protection are increasing. Microwave absorbers made from metamaterials have come to represent a viable option for stealth technology, as they employ custom-designed structures to absorb electromagnetic waves. As two-dimensional metamaterials, metasurfaces control incident waves precisely through periodic unit designs.MethodsThis paper proposes a novel metasurface structure for absorbing oblique incident EM waves. The design composed of double layer metamaterial where the first layer consists of fiber glass which is enforced by epoxy laminate. The second layer is made up of irregular metal patches and linked by metal rings and chip resistors.Results and DiscussionSimulation results show that the proposed metasurface has better absorption capability as compared with existing designs.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fphy.2026.1789490</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fphy.2026.1789490</link>
        <title><![CDATA[Thermal and mechanical stability enhancement of a 635 nm Littman-type external cavity diode laser]]></title>
        <pubdate>2026-04-07T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Maolei Zhang</author><author>Jinlian Chen</author><author>Yong Wang</author><author>Xiaofeng Wang</author><author>Hongpeng Wu</author><author>Fang Dong</author><author>Lei Dong</author>
        <description><![CDATA[Precise wavelength control in Littman-type external cavity diode laser (ECDL) is crucial for high-resolution spectroscopy and metrology, yet their stability is often limited by thermo-mechanical perturbations. Despite active temperature control of the laser diode, the thermal and mechanical response of the entire cavity structure remains a critical challenge. This study investigates these effects using a multi-physics coupled three-dimensional finite-element model, incorporating realistic parameters of the laser diode, diffraction grating, mirror assembly, and thermoelectric controller to analyze temperature distribution, thermal stress, and structural deformation under varying ambient temperatures. The results show that while active temperature control effectively suppresses thermal fluctuations in the laser diode, significant temperature non-uniformity develops on the diffraction grating as the ambient temperature increases, with the surface temperature difference rising from 3.31 K to 6.91 K. Thermally induced structural deformation leads to changes of 0.453 μm in the internal cavity length, 10.983 μm in the external cavity length, and an angular deviation of 0.022 in the optical feedback path. These coupled effects result in an output wavelength drift of 0.191 nm (corresponding to a wavelength-temperature sensitivity of 9.55 pm/K), exceeding the stability requirements for precision wavelength control. The analysis clarifies the dominant thermo-mechanical mechanisms limiting wavelength stability in Littman-type ECDL and provides guidance for structural and thermal optimization in precision laser applications. A subsequent sensitivity analysis reveals that under realistic thermoelectric controller (TEC) stabilization (±0.01 K), the thermo-mechanically induced wavelength drift is suppressed to ±0.0955 pm, validating the engineering relevance of the proposed model.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fphy.2025.1727157</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fphy.2025.1727157</link>
        <title><![CDATA[Overview of stressed liquid crystal]]></title>
        <pubdate>2026-04-01T00:00:00Z</pubdate>
        <category>Mini Review</category>
        <author>Jiahui Chen</author><author>Lin Xu</author><author>Chi Zhang</author><author>Xitong Liang</author><author>Ziling Chen</author><author>Han Zheng</author><author>Xu Wang</author><author>Zhen Pang</author><author>Dongshen Lv</author><author>Hengbo Huang</author><author>Gaoyang Liu</author><author>Jiacheng Dong</author><author>Chenxuan Ren</author><author>Youyou Hu</author>
        <description><![CDATA[Stressed liquid crystal (SLC), discovered 20 years ago in the study of polymer dispersed liquid crystals and polymer network liquid crystals, has attracted great interest from researchers. SLC achieves decoupling of liquid crystal film thickness and switching speed, representing a significant breakthrough in fast response and large phase modulation materials. This paper reviews the related concepts of stressed liquid crystals, precautions in their preparation, and summarizes factors affecting their electro-optic properties; it also introduces research progress and discusses future development directions in applications such as smart glass, tunable attenuators, Fourier spectrometers, adaptive optics, liquid crystal shutters, tunable gratings, and optical phased arrays. Analysis of existing research indicates that stressed liquid crystals have important applications and industrial potential in high-speed dynamic networks, passive smart dimming, miniature Fourier spectrometers, AR/VR dynamic focusing, laser communication beam control, and high-resolution liquid crystal shutters.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fphy.2026.1795521</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fphy.2026.1795521</link>
        <title><![CDATA[Inversion of the forest dead fuel moisture content by UAV multisepectral image under the new leaves shade]]></title>
        <pubdate>2026-03-26T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Ye Wang</author><author>Xinning Wang</author><author>Jian Xing</author>
        <description><![CDATA[Forest dead fuel moisture content (FDFMC) is an important factor affecting the occurrence and spread of forest fires. When the leaves have completely fallen, because of no leaves shade, the use of UAV multispectral cameras can achieve the spectral images easily. However, during the spring fire prevention period, it is difficult to obtain the full spectral images because of the shade of new leaves, therefore the inversion accuracy of FDFMC would be greatly affected by it. In this paper, an improved ConvNeXt convolutional neural network is proposed to predict FDFMC based on UAV multispectral camera data from 18 to 25 April 2025 in the urban forestry demonstration in Harbin City. A total of 6,031 sets of photos were captured using UAV multispectral camera, with each set containing six single-band images. The K-means clustering algorithm is used to segment the UAV multispectral images to extract the feature information for reducing the influence of new leaves shade. The trained model achieved 1.38% for MAE and 4.54% for RMSE. The experimental results showed that the improved ConvNeXt model can accurately predict the FDFMC. The new method proposed in this paper for predicting the FDFMC using the UAV multispectral images has feasibility and reference significance.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fphy.2026.1816429</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fphy.2026.1816429</link>
        <title><![CDATA[Integrable elastic fiber-optic tactile sensors for fingertip stress perception]]></title>
        <pubdate>2026-03-23T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Xinyue Weng</author>
        <description><![CDATA[Tactile sensors with high softness and multiplexing are highly desirable for applications in humanoid robotics and smart prosthetics. Current tactile sensors face bottlenecks in multi-channel dynamic sensing based on miniaturized and economical signal demodulation devices especially for manipulator grasping motion. Integrating tactile sensors into the manipulator fingertip and developing multi-channel chip scale optoelectronic demodulation device are promising to overcome previous limitations. Here, an integrable elastic fiber-optic tactile (IEFT) sensor enabled by a fiber-optic Sagnac interferometer is reported. The tactile sensor is fabricated by encapsulating a macro-bending fiber-optic Sagnac interferometer in an elastomeric silicone fingertip structure. The finger body is made of photosensitive resin, which fits perfectly with the fingers of a mechanical hand. Through optoelectronic signal demodulation integration, the tactile sensors array is able to distinguish different finger actions such as pressing, sliding, pinching, and gripping motion. Five-channel finger tactile sensors show an excellent stress sensing detection limit of 0.05 N and a response time less than 300 ms. Such tactile sensing system achieves miniaturized, economical dynamic measurement. The developed sensors array may pave the way for perception of surface shape and hardness, as well as robot hand motion recognition.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fphy.2026.1829342</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fphy.2026.1829342</link>
        <title><![CDATA[Correction: 10 kHz repetition rate picosecond green laser for high-accuracy satellite ranging]]></title>
        <pubdate>2026-03-23T00:00:00Z</pubdate>
        <category>Correction</category>
        <author>Zhongwei Fan</author><author>Xiaopeng Liu</author><author>Zhongping Zhang</author><author>Wendong Meng</author><author>Mingliang Long</author><author>Zhenao Bai</author>
        <description></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fphy.2026.1769213</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fphy.2026.1769213</link>
        <title><![CDATA[Integrating machine learning and statistical methods for optical aberration analysis in fluidic lenses]]></title>
        <pubdate>2026-03-12T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Graciana Puentes</author>
        <description><![CDATA[A combination of statistical inference and machine learning (ML) schemes has been utilized to create a thorough understanding of coarse experimental data based on Zernike variables characterizing optical aberrations in fluidic lenses. A classification of surplus-response variables through tolerance manipulation was included to unravel the dimensional aspect of the data. Similarly, the impact of the exclusion of supererogatory variables through the identification of clustering movements of constituents is examined. The method of constructing a spectrum of collaborative results through the application of similar techniques has been tested. To evaluate the suitability of each statistical method before its application on a large dataset, a selection of ML schemes has been proposed. The unsupervised learning tools principal component analysis (PCA), factor analysis (FA), and hierarchical clustering (HC) were employed to define the elemental characteristics of Zernike variables. PCA enabled to reduce the dimensionality of the system by identifying two principal components which collectively account for 95% of the total variance. The execution of FA indicated that a specific tolerance of independent variability of 0.005 could be used to reduce the dimensionality of the system without losing essential data information. A high cophenetic coefficient value of c=0.9629 validated an accurate clustering division of variables with similar characteristics. The current approach of mutually validating ML and statistical analysis methods will aid in laying the groundwork for advanced analysis. Its benefit is reflected in the associated state-of-the-art (SOTA) framework, which enhances predictive performance by integrating multiple complementary methods rather than relying on a single, arbitrarily selected ML model, as is in conventional SOTA analyses.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fphy.2026.1791434</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fphy.2026.1791434</link>
        <title><![CDATA[A resonant photoacoustic spectroscopy sensor for ppb-level detection of acetylene employing a 1.53 μm laser diode]]></title>
        <pubdate>2026-03-05T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Lei Peng</author><author>Yihua Qian</author><author>Yaohong Zhao</author><author>Qing Wang</author><author>Yifeng Zhao</author><author>Qiang Fu</author>
        <description><![CDATA[A compact and highly sensitive photoacoustic spectroscopy (PAS) sensor for dissolved acetylene (C2H2) detection was developed for transformer fault diagnosis applications. A 1.53 μm distributed-feedback (DFB) diode laser targeting the ν1 + ν3 absorption line of acetylene at ∼1530.37 nm was employed, benefiting from strong line intensity and high transparency of transformer oil in the near-infrared region. Wavelength modulation spectroscopy combined with second-harmonic (2f) demodulation was implemented, and the modulation depth was optimized to 120 mVpp to achieve the maximum normalized 2f signal. A high-Q resonant photoacoustic cell was designed to enhance the acoustic response and improve the signal-to-noise ratio. Experimental results demonstrated excellent linearity (R2 = 0.999) over the concentration range of 200–1,000 ppm. For a standard 100 ppm C2H2/N2 mixture, a peak 2f signal amplitude of 5.4 × 10−5 V was obtained, with a noise level of 4.05 × 10−7 V (1σ). Allan deviation analysis further confirmed the outstanding long-term stability of the system, achieving a detection sensitivity of 0.75 ppm at 1 s and a minimum detection limit of 50 ppb at an integration time of 3,200 s. These results indicate that the proposed PAS sensor enables accurate, real-time, and trace-level acetylene detection, demonstrating strong potential for dissolved gas analysis in transformer oil and early warning of incipient arcing faults.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fphy.2026.1791440</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fphy.2026.1791440</link>
        <title><![CDATA[Comparison and excitation optimization of commercial quartz tuning forks for QEPAS]]></title>
        <pubdate>2026-03-04T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Lei Peng</author><author>Yihua Qian</author><author>Yaohong Zhao</author><author>Qing Wang</author><author>Yifeng Zhao</author><author>Qiang Fu</author>
        <description><![CDATA[Quartz-enhanced photoacoustic spectroscopy (QEPAS) is a powerful technique for trace gas sensing, in which the quartz tuning fork (QTF) plays a key role in determining detection performance. Although custom-designed QTFs have shown enhanced sensitivity, commercially available QTFs remain attractive for practical QEPAS sensors due to their low cost and high reproducibility. In this work, four commercial quartz tuning forks with different geometrical parameters and resonance frequencies are systematically investigated for water vapor detection. The resonance characteristics of each QTF are experimentally measured, and the laser excitation position is individually optimized according to the tuning fork geometry. Using a 1,392 nm distributed feedback laser and a 1.8% H2O sample, the QEPAS performance of the four QTFs is compared under optimized conditions. Significant differences are observed in optimal excitation position, signal amplitude, and signal-to-noise ratio, with the standard 32.7 kHz QTF achieving the highest SNR of 430.4. These results demonstrate that commercial QTFs cannot be treated as interchangeable components and provide practical guidance for their selection and optimization in cost-effective QEPAS sensors.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fphy.2026.1768836</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fphy.2026.1768836</link>
        <title><![CDATA[Low-profile miniaturized dielectric resonator array antenna design for frequency division duplex based on sequential rotation method]]></title>
        <pubdate>2026-02-25T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Mohd Aliff Afira Sani</author><author>Nor Samsiah Sani</author><author>Michal Prauzek</author><author>Jaromir Konecny</author><author>Hung Tran-Huy</author><author>Trang Hoang-Thu</author><author>Iyas Qaddara</author><author>Heba G. Mohamed</author><author>Darius Andriukaitis</author>
        <description><![CDATA[IntroductionThe antenna must adhere to more stringent requirements, including multi-band operation, high performance, and compact design, since it is the primary component of satellite communication systems. A shared-aperture antenna based on structural reuse is a viable method for attaining multi-band functionality of satellite communication systems and improving platform space usage. The development of multi-function antennas, antenna size reduction for shrinking, and cost reduction are all greatly impacted by shared-aperture technology. Because of the significance of L-band applications, the development of circularly polarized (CP) antennas has grown in importance. Because of their compensations, which include lower multipath losses and polarization mismatch, CP antennas are essential for many wireless applications, such as GNSS, satellite communication, and indoor wireless systems.MethodsThis paper proposes a novel dielectric resonator array antenna. The shared-aperture feature is established by merging the dielectric high-frequency resonators in the annular dielectric low-frequency resonators. By controlling the phase difference between the degenerate modes, the low and high frequency orthogonal circularly polarized waves are created. The impedance matching is improved by optimizing the thickness of the circular cylindrical dielectric resonator. The sequential rotation method is used to design the array antenna.Results and DiscussionSimulation results show that the proposed dielectric resonator array antenna has superior performance and improved polarization characteristics as compared with existing methods.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fphy.2026.1744525</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fphy.2026.1744525</link>
        <title><![CDATA[Plane-wave scattering by asymmetric mesoscale semicylinder: controllable formation of multiple interrelated photonic nanojets]]></title>
        <pubdate>2026-02-18T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>O. V. Angelsky</author><author>A. Y. Bekshaev</author><author>C. Yu. Zenkova</author><author>M. S. Gavrylyak</author><author>P. P. Maksimyak</author><author>O. P. Maksimyak</author><author>S. Shchukin</author><author>J. Zheng</author><author>J. Cai</author>
        <description><![CDATA[This work reveals new possibilities for creating controllable photonic nanojets (PNJs) and their complexes, “photonic multijets” (PMJs), characterized by the specific morphological and energy-concentrating properties. These specific light structures can be generated upon scattering a monochromatic plane wave by a mesoscale dielectric semicylinder (SC) with geometric asymmetry (its flat surface is inclined with respect to the incident wave). An output field in the form of PMJ unites several interrelated PNJs of comparable intensities. The main spatial features of the separate PNJs, produced in this process, and their interrelations, are investigated via computer modeling based on the COMSOL Multiphysics environment and finite-difference time-domain (FDTD) method. The number, positions, orientations and intensities of the PNJs depend on the SC size, orientation and dielectric parameters as well as on the exciting-light wavelength. The modeling results show the possibilities for purposeful creation and control of the PMJs with desirable characteristics. In particular, excitation by bi-chromatic light with two different wavelengths enables realization of a passive switching element capable of dynamically altering the electromagnetic field distribution depending on the irradiation spectrum. This can be used for creation of optical splitters and switching devices. Their potential characteristics are discussed as well as the prospects for experimental implementation and applications in optical signal-processing systems.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fphy.2026.1780345</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fphy.2026.1780345</link>
        <title><![CDATA[LiDAR point cloud down-sampling strategy with multi-dimensional membership fusion]]></title>
        <pubdate>2026-02-13T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Xue Cao</author><author>Zhongqi Feng</author><author>Weiwei Mao</author>
        <description><![CDATA[This study devises an innovative LiDAR point cloud down-sampling strategy that capitalizes on the properties of Fuzzy C Means (FCM) clustering membership functions in each dimension. Traditional down-sampling methods frequently encounter difficulties in striking a balance between computational efficiency and feature preservation, particularly for large-scale datasets. To tackle this issue, our approach breaks down the three-dimensional simplification problem into independent one-dimensional analyses. Specifically, FCM clustering is carried out separately on the X, Y, and Z coordinates to generate dimension-wise membership functions. These functions are then intelligently integrated to calculate comprehensive importance scores for each point, facilitating adaptive sampling that eliminates redundant data while retaining critical geometric features. Experimental results demonstrate that our method outperforms conventional approaches, including voxel grid, random, and farthest point sampling, in terms of geometric fidelity. The proposed method shows strong potential for real-time applications involving large-scale point clouds in fields such as autonomous driving, robotic navigation, and 3D reconstruction.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fphy.2026.1732730</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fphy.2026.1732730</link>
        <title><![CDATA[Design of 12.5 MHz ultrashort passively mode-locked Figure-9 holmium-doped fiber laser implemented using different reflectors]]></title>
        <pubdate>2026-01-19T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Jawad Mirza</author><author>Ahmad Atieh</author><author>Serhat Boynukalın</author><author>Benish Kanwal</author><author>Imran Aziz</author><author>Ahmad Almogren</author>
        <description><![CDATA[Special cavities like Figure-8 and Figure-9 are exploited in lasers to enable self-starting passive mode-locking using nonlinear amplifying loop mirrors (NALMs) or nonlinear optical loop mirrors (NOLMs). Their significance lies in enhanced nonlinearity and intracavity feedback, enabling stable, self-sustained mode-locked pulses suitable for ultrafast fiber lasers. In this paper, we propose the design of femtosecond pulse width passively mode-locked Holmium-doped fiber laser (HDFL) operating at 2090 nm and 12.5 MHz repetition rate based on Figure-9 (F9) cavity. The F9 cavity is implemented utilizing three different reflectors, including saturable absorber (SA), simple mirror (SM), and fiber loop mirror (FLM). The performance of the proposed laser is compared for different reflectors considering characteristics of slope efficiency (SE), pulse width, optical signal to noise ratio (OSNR), peak power, and pulse energy. SA, SM, and FLM configurations yield mode-locked pulses with SEs of 35.6%, 8%, and 8.8%, pulse widths of 357.2 fs, 294 fs, and 231 fs, OSNRs of 36.4 dB, 46 dB, and 50 dB, peak powers of 13.53 kW, 6.12 kW, and 9 kW, and pulse energies of 4.83 nJ, 2 nJ, and 2.1 nJ, respectively. The analysis reveals that the FLM-based reflector achieves the shortest pulse width and highest OSNR, while the SA-based reflector delivers the highest peak power and pulse energy, highlighting trade-offs between pulse quality and energy performance in the proposed laser design.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fphy.2025.1734499</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fphy.2025.1734499</link>
        <title><![CDATA[Optical microelastography via a 2D boundary condition-free nonlinear inversion approach]]></title>
        <pubdate>2026-01-13T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Sajad Ghazavi</author><author>Hari S. Nair</author><author>Guillaume Flé</author><author>Boris Chayer</author><author>Ruchi Goswami</author><author>Salvatore Girardo</author><author>Jochen Guck</author><author>Guy Cloutier</author><author>Elijah E. W. Van Houten</author>
        <description><![CDATA[The mechanical phenotype of a cell, including its viscoelastic properties, is recognized as a label-free biomarker for diagnosing cellular states. Optical microelastography (OME) assesses intracellular mechanical heterogeneity by mapping the shear modulus distribution within cells using time-harmonic elastic waves observed within an optical image plane. However, reconstructing viscoelastic properties at the microscale is challenging not only because of inherent scale limitations, but also because, in OME, the complex 3D wave motion is only tracked within a single 2D plane. To address this challenge, a 2D boundary-condition-free nonlinear inversion (2D-NoBC-NLI) method is introduced to reconstruct viscoelastic properties from noisy 2D displacement fields. Numerical simulations of a homogeneous sphere, a heterogeneous sphere, and an asymmetric nucleated cell were designed to assess the robustness of 2D-NoBC-NLI reconstructions. Experiments were conducted on homogeneous, 75 µm-diameter polyacrylamide (PAAm) microbeads, which were expected to yield uniform viscoelasticity maps. With optimum parameter conditions, the proposed 2D-NoBC-NLI approach achieved mean reconstruction errors ranging from 1 to 13% across all simulated models. Within homogeneous PAAm microbeads, the method demonstrated frequency dependency of viscoelastic parameters consistent with previous measurements. The proposed nonlinear inversion algorithm enables storage and loss moduli imaging without out-of-plane motion data, and without using simplifying 2D approximations. This technique supports 2D elastography imaging and may enable OME-based cell mechanobiology studies through spatially resolved viscoelastic property mapping.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fphy.2025.1754822</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fphy.2025.1754822</link>
        <title><![CDATA[Dome-shaped nanostructured wide-bandgap perovskite for tandem solar cell applications]]></title>
        <pubdate>2026-01-08T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Ahmed Fathi Salem</author><author>Mohamed Farhat. O. Hameed</author><author>Hamdy Abdelhamid</author><author>Sanaa M. El-Rabaie</author><author>S. S. A. Obayya</author><author>R. El-Bashar</author>
        <description><![CDATA[The development of wide-bandgap perovskite materials has enabled new opportunities for highly efficient tandem solar cell applications. In this study, the optical and electronic performance of a single junction dome-shaped nanostructured wide-bandgap perovskite (MA0.9Cs0.1Pb(I0.6Br0.4)3) is studied for all-perovskite tandem solar cell (SC) applications. The optical performance of the proposed design is studied using finite difference time domain. The introduction of the dome-shaped (Al2O3) antireflective layer improves the light absorption to 90.1% relative to 77.1% for the PSC without antireflective coating (ARC). Therefore, the maximum power conversion efficiency (PCE) of 15.3% is reported for the optimized structure (Eg = 1.82 eV) with an enhancement of 19.5% compared to the reference cell. When the defect density is increased to 1018 cm-3, the PCE is dropped to 7.7% with a reduction of 49.7% relative to the studied good practical defect density of 1015 cm-3. Furthermore, the impact of the perovskite bandgap on the electrical parameters of the perovskite solar cells (PSCs) device is analyzed. The optimized structure with a bandgap of 1.9 eV shows the highest PCE of 16.1% with a JSC of 18.1 mA/cm2. The results show that the presence of Al2O3 ARC enhances the performance of PSC, which can be useful for tuning wide-bandgap perovskite in tandem photovoltaic systems.]]></description>
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