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        <title>Advanced Optical Technologies | New and Recent Articles</title>
        <link>https://www.frontiersin.org/journals/advanced-optical-technologies</link>
        <description>RSS Feed for Advanced Optical Technologies | New and Recent Articles</description>
        <language>en-us</language>
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        <pubDate>2026-05-03T16:02:00.732+00:00</pubDate>
        <ttl>60</ttl>
        <item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/aot.2026.1837544</guid>
        <link>https://www.frontiersin.org/articles/10.3389/aot.2026.1837544</link>
        <title><![CDATA[Editorial: Advanced fabrication techniques for high-precision optical components]]></title>
        <pubdate>2026-04-14T00:00:00Z</pubdate>
        <category>Editorial</category>
        <author>Xiaohua Liu</author><author>Allen Yi</author><author>Thomas Bifano</author><author>Yiquan Wu</author>
        <description></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/aot.2026.1727895</guid>
        <link>https://www.frontiersin.org/articles/10.3389/aot.2026.1727895</link>
        <title><![CDATA[Enhancement of channel capacity of IRS-aided OWC system for 6G wireless communication]]></title>
        <pubdate>2026-03-23T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Ashutosh Pande</author><author>Pankaj Shankar Shrivastava</author><author>Bhanu P. Singh</author><author>Prakash Kumar</author>
        <description><![CDATA[To meet the stringent ultra-reliable connectivity demands of 6G applications such as enhanced broadband and autonomous driving, optical wireless communication (OWC) is considered a key candidate technology. In this work, we investigate the performance of an intelligent reflecting surface (IRS)-aided OWC system by analyzing the signal-to-interference-plus-noise ratio (SINR), data rate, and sum rate through comprehensive MATLAB simulations. The impact of key system parameters on these performance metrics is systematically studied. Furthermore, an analytical expression for the optimal line-of-sight (LoS) channel gain is derived to maximize SINR, data rate, and sum rate. This optimization enables the selection of higher-order M-pulse amplitude modulation (M-PAM) schemes, thereby enhancing channel capacity (CC), spectral efficiency (SE), and energy efficiency (EE) of the IRS-aided OWC system. Simulation results demonstrate that for an SINR of 14.52 dB, 4-PAM is identified as the most suitable advanced digital modulation scheme for reliable data transmission. Additionally, the proposed system achieves a maximum sum rate of 32 Mbps for two mirror arrays and two blockages, which is approximately three times higher than the corresponding results reported in the existing literature. These findings highlight the substantial potential of IRS-assisted OWC systems as an enabling technology for future 6G networks.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/aot.2026.1704376</guid>
        <link>https://www.frontiersin.org/articles/10.3389/aot.2026.1704376</link>
        <title><![CDATA[Terahertz time-of-flight contrast for non-destructive visualization of bruchid damage in lentils: a feasibility study]]></title>
        <pubdate>2026-03-12T00:00:00Z</pubdate>
        <category>Methods</category>
        <author>Jean-Paul Guillet</author><author>Jean-François Berthoumieu</author><author>François Demontoux</author>
        <description><![CDATA[Lentils are a key source of plant-based proteins, but their quality can be compromised by bruchids, insects that burrow inside the seeds, causing internal damage. Current detection methods rely on destructive testing, which is time-consuming, costly, and results in the loss of part of the batch. In this study, we demonstrate the potential of terahertz time-domain imaging in transmission as a non-destructive and effective method for detecting bruchids in lentils. The approach provides rapid and precise assessment, preserving the integrity of the samples and enabling quality control for the agro-industrial sector. Beyond accurate quality evaluation, this method holds promise for future applications in automated sorting systems, improving product valuation and market competitiveness. By leveraging terahertz technology, we present an innovative solution that aligns with the needs of producers, distributors, and consumers. This work is a qualitative proof-of-concept aimed at establishing physical feasibility. It does not estimate diagnostic performance (sensitivity/specificity); a powered validation on concealed larvae is planned.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/aot.2026.1745190</guid>
        <link>https://www.frontiersin.org/articles/10.3389/aot.2026.1745190</link>
        <title><![CDATA[Manufacturing of a toroidal mold for the production of polymeric lenses]]></title>
        <pubdate>2026-02-17T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Agustin Santiago-Alvarado</author><author>Fermín S. Granados-Agustin</author><author>Oliver Huerta-Carranza</author><author>Víctor M. Cruz-Martínez</author><author>Jorge Alvarado-Martínez</author><author>Maximino Avendaño-Alejo</author>
        <description><![CDATA[The manufacture of optical molds for generating optical components in continuous or batch production has become a great challenge as freeform components are increasingly required. New manufacturing techniques have emerged to meet these technological demands; however, freeform optics present previously unseen manufacturing challenges as traditional optical workshops are designed to produce components with spherical shapes. The mold technique is widely used for batch production, but the main challenge is mold manufacturing. Therefore, the manufacturing process of a toroidal 6061 aluminum optical mold is presented, using a CNC milling machine. To evaluate the finish of the toroidal surface, null screen tests and coordinate measurements were used as these methods allow changes in slopes across the entire surface to be measured in a single evaluation, which is not possible with other tests. The results obtained show that implementation is feasible at a reduced cost, with a Peak to-Valley (PV) error of 0.1806 mm and an Root Mean Square (RMS of 0.0402 mm in the surface finish, which can be further improved by taking the polishing stage as a guide.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/aot.2025.1730807</guid>
        <link>https://www.frontiersin.org/articles/10.3389/aot.2025.1730807</link>
        <title><![CDATA[PSO-based imaging restoration method for diffraction imaging systems]]></title>
        <pubdate>2026-01-07T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Can Li</author><author>Lianghua Wen</author><author>Guochun Liu</author><author>Zhengcong Du</author><author>Jiaxun Li</author><author>Tong Yang</author><author>Sanxiu Jiao</author>
        <description><![CDATA[Membrane diffraction imaging is one of the most widely used imaging technologies today, which offers the advantages such as lightweight design, large aperture, foldability, and low cost. However, the system imaging quality degrades because of the multiple order diffraction generated by the diffractive elements in practical applications. To eliminate the effects of multiple diffraction orders from the diffractive elements and optimize imaging quality, the system images are post processed. Iterative optimization algorithms are commonly used for image post processing. Particle swarm optimization is a commonly used iterative optimization algorithm, which is often used to search for optimal solutions within the solution space. The particle swarm optimization algorithm has the features of few parameters, simple behavior, and fast iteration speed, which can rapidly and effectively optimize imaging. This paper optimizes the simulated imaging of a diffraction imaging system based on Fresnel zone plates by adopting the particle swarm optimization algorithm. Optimize the system image based on known point spread functions and the system image. System imaging is optimized under the premise of known point spread functions and system imaging. The iteration speed is enhanced, reducing the number of iterations by approximately 99.6% compared to the random parallel gradient descent algorithm. Simultaneously, contrast is improved by about 5.4%, while gradient optimization effectiveness increases by approximately 25.4% after optimization by the particle swarm algorithm. Finally, the derived restoration model was applied to other images, achieving overall improvements in all evaluation metrics.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/aot.2025.1739755</guid>
        <link>https://www.frontiersin.org/articles/10.3389/aot.2025.1739755</link>
        <title><![CDATA[Performance analysis of a multi-format compatible all-optical data access method for satellite backbone-networks]]></title>
        <pubdate>2026-01-06T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Xinning Huang</author><author>Yuerong Shen</author><author>Daming Song</author>
        <description><![CDATA[Optical inter-satellite links are a promising technology for constructing satellite backbone networks, owing to their high data transmission capacity and lightweight terminals. To circumvent the data-rate bottlenecks and structural complexity associated with optical-electrical-optical conversion, all-optical signal processing is essential. This paper addresses a common challenge at the relaying nodes of satellite backbone networks: handling concurrent access requests from multiple laser links. We propose and validate an all-optical data access system based on an optical time-lens. The system demonstrates robust performance and high modulation format compatibility. It successfully processes intensity-modulated, phase-modulated, and hybrid-format inputs entirely in the optical domain. The system’s reliability is further confirmed under practical conditions, including uneven wavelength spans and unequal data rates among the accessing links. It achieves bit-error rates below 10−7 and supports optical inter-satellite link transmission distances exceeding 4,500 km, even under hybrid modulation formats. With its simple structure and high compatibility, the proposed system offers a scalable solution for future multi-format satellite backbone networks.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/aot.2025.1707828</guid>
        <link>https://www.frontiersin.org/articles/10.3389/aot.2025.1707828</link>
        <title><![CDATA[Near infrared spectroscopy assessment of wrist-based vascular occlusion protocols]]></title>
        <pubdate>2025-12-29T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Vanja Dvekar</author><author>Faraz Sadrzadeh-Afsharazar</author><author>Leah DeVos</author><author>Gennadi Saiko</author><author>Alexandre Douplik</author>
        <description><![CDATA[BackgroundVascular occlusion tests (VOTs) are widely used to assess microvascular function with near-infrared spectroscopy (NIRS), but protocols vary substantially, particularly in occlusion pressure and anatomical site. Most studies focus on the upper arm or thigh, with few studying distal limbs such as the wrist, highlighting the importance of standardizing wrist-based arterial occlusion pressures.MethodsTo address this gap, the present study examined the effects of two fixed occlusion pressures, 150 mmHg and 200 mmHg, applied at the wrist on the local muscle oxygenation dynamics. A total of 21 healthy participants underwent an 8-min experimental protocol comprising a 1-min baseline (no pressure), 3-min occlusion, and 4-min reperfusion period. Muscle oxygenation was continuously monitored from the thenar eminence of the occluded hand using a commercial near-infrared spectroscopy (NIRS) device (Moxy, Hutchinson, USA).ResultsReactive hyperemia responses at the two pressures were compared for five distinct metrics: amplitude of muscle oxygen saturation (SmO2)(p=0.0065), time to maximum SmO2(p=0.235), and three first-derivative features: time to peak slope (p=0.694), peak slope value (p=0.019), and full width at half maximum (FWHM) (p=0.46). Statistically significant differences were observed in amplitude of SmO2, and peak slope value. However, the temporal metrics such as time to max SmO2, time at peak slope value, and FWHM, were not significantly different.ConclusionOverall, this study supports the potential of wrist-based AOP protocols and highlights the importance of selecting appropriate occlusion pressures and anatomical sites to optimize vascular response while minimizing patient discomfort. Given the wrist’s anatomical advantages, incorporating wrist-based occlusion into daily practice and clinical assessments may enhance its translational potential as a pressure occlusion site.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/aot.2025.1693523</guid>
        <link>https://www.frontiersin.org/articles/10.3389/aot.2025.1693523</link>
        <title><![CDATA[A fiber-delivered, multi-line nanosecond source for single-shot spectro-polarimetric scattering measurements]]></title>
        <pubdate>2025-11-19T00:00:00Z</pubdate>
        <category>Brief Research Report</category>
        <author>Thomas Livecchi</author><author>Ben E. Urban</author>
        <description><![CDATA[We here describe a nanosecond, multi-line laser source that preserves partial linear polarization after transmission through a 100-m large-core graded-index (GRIN) fiber. The system generates narrow emission lines between 473 and 600 nm, evenly spaced by the silica Raman shift of ∼440 cm-1, from a Q-switched nanosecond pump coupled into the fiber. Despite multimode propagation, the cascaded beams emerge close to diffraction-limited Gaussian profiles due to nonlinear mode self-cleaning, while the residual pump remains multimodal. Across the emission lines, the degree of linear polarization (DoLP) ranges from 0.1 to 0.6 depending on the wavelength. As an application, we demonstrate single-shot, multiwavelength spectro-polarimetric reflectance, simultaneously measuring DoLP at all cascaded lines. To our knowledge, this is the first demonstration of wavelength-dependent polarization retention through a 100-m large-core GRIN fiber.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/aot.2025.1560454</guid>
        <link>https://www.frontiersin.org/articles/10.3389/aot.2025.1560454</link>
        <title><![CDATA[Numerical and experimental analysis of a side -polished single-mode fiber for refractive index sensing]]></title>
        <pubdate>2025-10-10T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Muhammad Musavir Bilal</author><author>Ajmal Thottoli</author><author>Marco Grande</author><author>Servando Lopez-Aguayo</author>
        <description><![CDATA[In this paper, we introduce a comprehensive study, based on both numerical and experimental analyses, of side polished-single mode fibers (SP-SMF) to investigate their corresponding evanescent field interaction with air and liquid analytes such as water and isopropanol (IPA). On the one hand, the SP-SMF’s optical properties are numerically studied and analyzed by using the finite element method and the beam propagation method, and we find that the alteration of analytes at the sensing region enhances the change in the refractive index (RI) of the materials. On the other hand, we designed and built an ad-hoc experimental setup to characterize the SP-SMF when air, water, and IPA are introduced into the SP region. The sensitivity is measured as 1.207 V/RIU. The performance in terms of effective RI and transmittance are reported to show how these SP-SMFs can be efficiently used for calculating the liquid RI. The simulation and experimental results display the significant performance of the SP-SMF as a valuable sensing element.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/aot.2025.1431573</guid>
        <link>https://www.frontiersin.org/articles/10.3389/aot.2025.1431573</link>
        <title><![CDATA[Study of thick active region in a terahertz quantum-cascade laser]]></title>
        <pubdate>2025-07-22T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Rajesh Sharma</author>
        <description><![CDATA[The research in the area of terahertz (THz) radiation is a subject of intense discussion in the international scientific community owing to its various applications in the fields of defense systems, security, interstellar studies, imaging, and agriculture. Although most of these applications have captured the attention of researchers in recent years, the development of a THz radiation source that meets specific requirements remains a challenging task. In this regard, the emission frequencies of terahertz quantum-cascade lasers (THz QCLs) can be fine-tuned by adjusting the thickness of the quantum well and the height of the barriers. The electron distribution among three periods of a hybrid active region design QCL structure is numerically simulated to estimate the optical gain spectra and electric field strength values. The results of the numerical simulations are compared with those of the experimental investigations by fabricating a 23 μm-thick active region THz QCL wafer by using the molecular beam epitaxy (MBE) technique. The wafer is split into six portions (A–F) to investigate the transport and the lasing properties. The electrical power dissipated at 10 K for the 23 μm-thick active region THz QCL stripe processed from the central portion (B) of the wafer is found to be approximately 56 W at the current density value of 0.53 kAcm−2. The thick active region THz QCL investigated in the present work operates in both pulsed and continuous-wave modes at the desired emission frequencies, which is a unique feature of the interlaced design. The optical output power of the 23 μm-thick active region THz QCL stripe compared to the 12 μm-thick active region is enhanced, attributed to improved mode confinement. Therefore, optimal performance in the pulsed mode can be achieved with thick active region THz QCL stripes fabricated near the center of the parent wafer. Nevertheless, thin active region THz QCLs are more suitable for continuous-wave operation due to reduced heat dissipation.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/aot.2025.1588934</guid>
        <link>https://www.frontiersin.org/articles/10.3389/aot.2025.1588934</link>
        <title><![CDATA[Mold-glass interface adhesion mechanisms in precision glass molding]]></title>
        <pubdate>2025-07-14T00:00:00Z</pubdate>
        <category>Review</category>
        <author>Hanhan Zhao</author><author>Liangchi Zhang</author>
        <description><![CDATA[Precision glass molding (PGM) enables high-accuracy, efficient production of complex optical components, yet interfacial adhesion between mold and glass surfaces remains a significant barrier, impacting both quality and mold durability. This review comprehensively examines the factors influencing adhesion behavior, including the roles of material selection, surface wettability, process parameters, and thermodynamic principles in defining interfacial performance. Through a detailed analysis of anti-adhesion materials and optimized process strategies, such as controlled temperature, pressure, and atmospheric conditions, this work elucidates mechanisms that mitigate adhesion and extend mold life. Thermodynamic modeling, including work of adhesion calculations, provides a quantitative foundation for predicting interfacial behavior, offering guidance for material and process optimization in PGM applications. The findings provide a multi-dimensional framework for addressing adhesion challenges in PGM, setting the stage for enhanced efficiency and quality in precision optics manufacturing.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/aot.2025.1583836</guid>
        <link>https://www.frontiersin.org/articles/10.3389/aot.2025.1583836</link>
        <title><![CDATA[Efficient high-resolution microscopic ghost imaging via sequenced speckle illumination and deep learning from a single noisy image]]></title>
        <pubdate>2025-06-24T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Sukyoon Oh</author><author>Tong Tian</author><author>Zhe Sun</author><author>Christian Spielmann</author>
        <description><![CDATA[This study presents a novel approach for achieving high-quality and large-scale microscopic ghost imaging by integrating deep learning-based denoising with computational ghost imaging techniques. By utilizing sequenced random speckle patterns of optimized sizes, we reconstructed large noisy images with fewer patterns while successfully resolving fine details as small as 2.2 μm on a USAF resolution target. To enhance image quality, we incorporated the Deep Neural Network-based Noise2Void (N2V) model, which effectively denoises ghost images without requiring a reference image or a large dataset. By applying the N2V model to a single noisy ghost image, we achieved significant noise reduction, leading to high-resolution and high-quality reconstructions with low computational resources. This method resulted in an average Structural Similarity Index (SSIM) improvement of over 324% and a resolution enhancement exceeding 33% across various target images. The proposed approach proves highly effective in enhancing the clarity and structural integrity of even very low-quality ghost images, paving the way for more efficient and practical implementations of ghost imaging in microscopic applications.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/aot.2025.1560084</guid>
        <link>https://www.frontiersin.org/articles/10.3389/aot.2025.1560084</link>
        <title><![CDATA[Progress in integrated and fiber optics for time-bin based quantum information processing]]></title>
        <pubdate>2025-04-11T00:00:00Z</pubdate>
        <category>Review</category>
        <author>Nicola Montaut</author><author>Agnes George</author><author>Monika Monika</author><author>Farzam Nosrati</author><author>Hao Yu</author><author>Stefania Sciara</author><author>Benjamin Crockett</author><author>Ulf Peschel</author><author>Zhiming Wang</author><author>Rosario Lo Franco</author><author>Mario Chemnitz</author><author>William J. Munro</author><author>David J. Moss</author><author>José Azaña</author><author>Roberto Morandotti</author>
        <description><![CDATA[The development of integrated photonic systems, both on-chip and fiber-based, has transformed quantum photonics by replacing bulky, fragile free-space optical setups with compact, efficient, and robust circuits. Photonic platforms incorporating fiber-connected sources of correlated and entangled photon pairs offer practical advantages, such as operation at room temperature, efficient integration with telecom infrastructure, and compatibility with mature and efficient semiconductor fabrication processes for cost-effective and large-scale optical circuits. The stability and scalability of integrated quantum photonics platforms have facilitated the generation and processing of quantum information in the temporal domain within a single spatial mode. Time-bin encoded states, known for their robustness against decoherence and compatibility with existing fiber-optic infrastructure, have shown to be an efficient paradigm for advanced applications like quantum secure communication, information processing, spectroscopy, imaging, and sensing. This review examines recent advancements in fiber- and chip-based platforms for generating non-classical states and their applications as quantum state processors in the time domain. We discuss the generation of pulsed quantum frequency combs using microring resonators and intra-cavity mode-locked laser schemes, enabling co- and cross-polarized quantum photonic states. Additionally, the versatility of these resonator chips for entanglement generation is emphasized, including two- and multi-photon time-bin entangled schemes. We highlight the development of time-bin entanglement analyzers in fiber architectures, featuring ultrahigh stability and post-selection-free capabilities, which enable precise and efficient characterization of two- and higher-dimensional time-bin entanglement. We also review scalable on-chip schemes for quantum key distribution, demonstrating low quantum bit error rates and compatibility with higher-dimensional quantum communication protocols. Further, methods for enhancing temporal resolution in detection schemes, crucial for time-bin encoding, are presented, such as the time-stretch sampling technique using electro-optic modulation. These innovations, relying on readily available, telecom-based fiber-optic components, provide practical, scalable, and cost-effective solutions for advancing quantum photonic technologies. Looking forward, time-bin encoding is expected to play a pivotal role in the advancement of quantum repeaters, distributed quantum networks, and hybrid light-matter systems, advancing the realization of globally scalable quantum technologies.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/aot.2025.1568420</guid>
        <link>https://www.frontiersin.org/articles/10.3389/aot.2025.1568420</link>
        <title><![CDATA[High resolution satellite imaging 0.5U-size freeform telescope for CubeSat]]></title>
        <pubdate>2025-03-21T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Jacek Wojtanowski</author>
        <description><![CDATA[IntroductionApart from discussing general issues related to the application of freeform telescopes, this work presents a design of ultra-compact high-resolution freeform telescope dedicated to CubeSat application associated with Earth surface imaging from Low Earth Orbit (LEO), providing high resolution (Ground Sampling Distance, GSD <5 m) and 20 km width of the observed Earth strip.MethodsThe telescope was designed in a three-mirror off-axis configuration according to the <0.5U volume constraint. Freeform surfaces were described by shifted polynomial equations. In order to prevent optimization falling into numerous local minima of multi-variate merit function, the new design strategy was proposed. The optical design commercial software was supplemented by add-on responsible for dynamically modifying the set of variables in the loop during the optimization process.ResultsThe designed 250 mm f/4.9 telescope meets the assumed operational and volumetric criteria. It fits into the volume of 5 × 10 × 10 cm cuboid. It is diffraction limited across the whole (3o) field of view.DiscussionFreeform optics design technology was successfully applied to design a miniature space telescope. The proposed design algorithm proved to be computationally efficient. It enabled to obtain the excellent imaging of the designed telescope, which from mathematical perspective becomes a challenging multi-variable optimization task, unattainable with the standard optimization procedures included in the commercial optical design software.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/aot.2025.1546386</guid>
        <link>https://www.frontiersin.org/articles/10.3389/aot.2025.1546386</link>
        <title><![CDATA[Deep learning for ultrafast X-ray scattering and imaging with intense X-ray FEL pulses]]></title>
        <pubdate>2025-03-13T00:00:00Z</pubdate>
        <category>Review</category>
        <author>Menglu Hu</author><author>Jiadong Fan</author><author>Yajun Tong</author><author>Zhibin Sun</author><author>Huaidong Jiang</author>
        <description><![CDATA[The advent of X-ray Free Electron Lasers (XFELs) has opened unprecedented opportunities for advances in the physical, chemical, and biological sciences. With their state-of-the-art methodologies and ultrashort, and intense X-ray pulses, XFELs propel X-ray science into a new era, surpassing the capabilities of traditional light sources. Ultrafast X-ray scattering and imaging techniques leverage the coherence of these intense pulses to capture nanoscale structural dynamics with femtosecond spatial-temporal resolution. However, spatial and temporal resolutions remain limited by factors such as intrinsic fluctuations and jitters in the Self-Amplified Spontaneous Emission (SASE) mode, relatively low coherent scattering cross-sections, the need for high-performance, single-photon-sensitive detectors, effective sample delivery techniques, low parasitic X-ray instrumentation, and reliable data analysis methods. Furthermore, the high-throughput data flow from high-repetition rate XFEL facilities presents significant challenges. Therefore, more investigation is required to determine how Artificial Intelligence (AI) can support data science in this situation. In recent years, deep learning has made significant strides across various scientific disciplines. To illustrate its direct influence on ultrafast X-ray science, this article provides a comprehensive overview of deep learning applications in ultrafast X-ray scattering and imaging, covering both theoretical foundations and practical applications. It also discusses the current status, limitations, and future prospects, with an emphasis on its potential to drive advancements in fourth-generation synchrotron radiation, ultrafast electron diffraction, and attosecond X-ray studies.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/aot.2025.1536415</guid>
        <link>https://www.frontiersin.org/articles/10.3389/aot.2025.1536415</link>
        <title><![CDATA[Remote physiological monitoring of neck blood vessels with a high-speed camera]]></title>
        <pubdate>2025-03-07T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Meiyun Cao</author><author>Gennadi Saiko</author><author>Alexandre Douplik</author>
        <description><![CDATA[IntroductionSeveral population-based clinical studies suggest that increased Pulse Wave Velocity (PWV) is highly associated with increased cardiovascular disease (CVD) mortality, which is one of the leading causes of death worldwide. Current methods for CVD detection are invasive, expensive, and contact methods, which are not friendly for skin-sensitive patients.MethodsIn this study, we investigated the use of remote photoplethysmography (rPPG) on the neck region using a high-speed camera (2000 frames per second (fps)) to resolve the drawbacks of CVD detection and overcome the limitations of current PWV measurement techniques. Pearson correlation and cross-correlation were used for signal processing and generating the projection map of potential major vessels. A reference signal is selected for the region of interest based on peak value and modulation depth variation. The signal distance and pulse transit time (PPT) between the local and reference signals were calculated using the cross-correlation method and then fitted into a linear regression model for PWV calculation.ResultsThe results revealed areas on the neck that positively and negatively correlated with the selected reference signals, potentially representing the distribution of the main neck vessels - carotid artery and jugular vein- and, consequently, the upstream and downstream blood circulation directions.DiscussionThis research implies the feasibility of touchless estimation of local PWV using a high-speed camera, expanding the potential applications of remote photoplethysmography in aiding the diagnosis of CVD.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/aot.2025.1474728</guid>
        <link>https://www.frontiersin.org/articles/10.3389/aot.2025.1474728</link>
        <title><![CDATA[MGL/SiNW-based exotic pin switch with low insertion loss and high isolation for THz communication: a quantum-rectified Schrodinger–Poisson drift-diffusion model for the design and analysis of switching behavior]]></title>
        <pubdate>2025-02-12T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Saunak Bhattacharya</author><author>Abhijit Kundu</author><author>Jhuma Kundu</author><author>Angsuman Sarkar</author><author>Moumita Mukherjee</author>
        <description><![CDATA[In this paper, the authors explore the potential of an exotic multi-graphene layer/Si nanowire (MGL/SiNW) pin device as a switch in the THz frequency domain. The device is developed by the incorporation of multiple SiNWs into its intrinsic region. In contrast, cap and bottom layers are developed by the incorporation of multiple graphene layers. The electrical characterization of the proposed exotic pin device is carried out by developing a quantum-rectified Schrodinger–Poisson drift-diffusion (QRSP-DD) model. The developed QRSP-DD model is validated by analyzing experimental and simulation observations under similar operating conditions. After establishing its validity, the same model in conjunction with the PSpice simulator is used to obtain the switching characteristics of MGL/SiNW pin-based series-shunt and shunt single-pole single-throw (SPST), single-pole double-throw (SPDT), and single-pole multiple-throw (SPMT) switches in the THz frequency domain. The analysis proves that the MGL/SiNW pin-based SPMT switch offers low resistance (0.56 Ω), high isolation (91.15 dB), and low insertion loss (0.007 dB) at 5 THz frequency compared to its SiNW counterpart.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/aot.2025.1511907</guid>
        <link>https://www.frontiersin.org/articles/10.3389/aot.2025.1511907</link>
        <title><![CDATA[Electromagnetic deformable mirror fabricated using silicon micromachining and stress-resilient assembly]]></title>
        <pubdate>2025-01-22T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Wenkuan (Kevin) Man</author><author>Thomas Bifano</author>
        <description><![CDATA[Introduction: This work presents a prototype electromagnetic actuation deformable mirror (DM) assembly with stress-resilient face sheet design.Methods: The DM face sheet design includes slender micromachined silicon pillars that are integrated with a silicon face sheet to reduce unpowered face sheet surface distortion caused by actuator adhesion stress.Results: The assembled deformable mirror prototype allowed bi-directional actuation with total stroke exceeding 20 μm. A two-step control method was used to improve the prototype dynamic performance, allowing settling time on the order of 1 ms. Prescribed references shapes were made on the prototype deformable mirror using closed-loop control.Discussion: While the simplified DM produced in this work has only 19 actuators and therefore has limited capacity to control complex shapes, the design and fabrication processes described and demonstrated in this work provide a promising approach to development of high-stroke magnetic DMs.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/aot.2024.1505036</guid>
        <link>https://www.frontiersin.org/articles/10.3389/aot.2024.1505036</link>
        <title><![CDATA[Exoplanet detection in rotational shearing interferometry through experimental setup and digital filtering techniques]]></title>
        <pubdate>2025-01-07T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Manuel Montes-Flores</author><author>Guillermo Garcia-Torales</author><author>Marija Strojnik</author>
        <description><![CDATA[The significant brightness contrast between stars and orbiting planets often hinders the detection of exoplanets. This paper presents the development and validation of an experimental setup and digital filtering techniques for a rotational shearing interferometer (RSI) aimed at enhancing exoplanet detection. The method leverages controlled phase shifts and spatial frequency modulation through Risley and Dove prisms to isolate faint planetary signals from dominant starlight. Laboratory experiments use HeNe lasers to simulate a star-planet system, and spatial filters ensure precise wavefront alignment. The interferometer’s rotational shearing capabilities enhance the accuracy of phase alignment, allowing for significant suppression of starlight and improved detection of planetary signals. Additionally, applying Fourier-based digital filtering techniques further enhances detection sensitivity by reducing background noise. Experimental results demonstrate an 80% reduction in noise and up to a 20% increase in detection sensitivity compared to traditional interferometric methods. The RSI’s performance represents a significant advancement in interferometric techniques, suggesting its potential for real-world astronomical applications. However, further optimization is required to address challenges associated with space-based observations. This work sets the foundation for future research aimed at refining optical configurations and digital filtering techniques for exoplanet detection.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/aot.2024.1501208</guid>
        <link>https://www.frontiersin.org/articles/10.3389/aot.2024.1501208</link>
        <title><![CDATA[Pruning and optimization of optical neural network as a binary optical trigger]]></title>
        <pubdate>2025-01-07T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Bokun Zhao</author><author>Xuening Dong</author><author>Kaveh Rahbardar Mojaver</author><author>Brett H. Meyer</author><author>Odile Liboiron-Ladouceur</author>
        <description><![CDATA[Optical neural networks implemented with Mach-Zehnder Interferometer (MZI) arrays are a promising solution to enable fast and energy-efficient machine learning inference, yet finding a practical application has proven challenging due to sensitivity to thermal noise and loss. To leverage the distinct advantages of integrated optical processors while avoiding its shortcomings given the current state of optical computing, we propose the binary optical trigger as a promising field of application. Implementable as small-scale application-specific circuitry on edge devices, the binary trigger runs binary classification tasks and output binary signals to decide if a subsequent energy intensive system should activate. Motivated by the limited task complexity, constrained area and power budgets of binary triggers, we perform 1) systematic, application-specific hardware pruning by physically removing specific MZIs, and 2) application-specific optimizations in the form of false negative reduction and weight quantization, as well as 3) sensitivity studies capturing the effect of imperfections in real optical components. The result is a customized MZI-mesh topology, MiniBokun Mesh, whose structure provides adequate performance and robustness for a targeted task complexity. We demonstrate in simulation that the pruning methodology achieves at least 50% less MZI usage compared to Clements and Reck meshes with the same input size, translating to at least between 4.6% and 24.2% savings in power consumption and a 40% reduction in physical circuitry footprint compared to other proposed unitary MZI topologies, sacrificing only 1%–2% drop in inference accuracy.]]></description>
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