bluuebunny/crossref_metadata_2025 huggingface dataset:
Elastomeric-coated FBGs for point-of-care diagnostics
Authors: Nagar Malhar A. , Mingoia Giovanni , Janner Davide
Published: October 2024

This study deploys the application of Fiber Bragg Gratings (FBGs) in physiological pressure monitoring by integrating an elastomeric, biocompatible coating ranging from 300-500μm, designed to improve sensor functionality for in-vivo pressure monitoring applications. FBGs are favored for their sensitivity, immunity to electromagnetic interference, and compact size, making them ideal for embedding within medical devices such as catheters and guidewires. However, their use has been limited by low inherent pressure sensitivity (3.14 pm/MPa) and the impracticality of thicker coatings described in previous studies. Our approach demonstrates that this unique coating not only boosts the pressure sensitivity significantly—surpassing 1.63 orders of magnitude (43.10 times)—but also enhances the signal-to-noise ratio of the optical signal. These advancements enable potential applications in high-resolution manometry, gastrointestinal pressure monitoring, intracranial and intracoronary blood pressure measurements, marking a significant step forward in medical diagnostics and monitoring.
M-Cube — towards correlative multi-scale light-sheet imaging using a compact, modular and moving illuminator
Authors: Touja Hugo , Brau Frédéric , Bastien Thierry , Delhomme Brigitte , Oheim Martin
Published: October 2024

The crossed arrangement of excitation and collection optics is the defining feature of selective plane illumination microscopes. It results in an axial sectioning given by the thickness of the light sheet, whereas the lateral resolution depends on the numerical aperture of the collection optics. One disadvantage of this optical scheme is that it has been difficult to image large fields-of-view at high spatial resolution. Yet, it is often not necessary to image the entire sample at high resolution. Instead, a zoom from mm-scale over-views to regions-of-interest that are imaged at μm is often sufficient, e.g., for studying neuronal networks that simultaneously comprise cm-long connections and tiny (sub-μm) synaptic contacts, spanning 6 orders of magnitude. Observations over such different spatial scales typically require the use of different instruments. We here describe our ongoing efforts to build and characterise a compact light-sheet module designed for correlative micro- meso- and macroscopic imaging. Its particularity is that moves with the sample between micro- and macroscopic imaging arms. Based on a compact illuminator and flexible sample carrier the module is mounted on a motorised long-range, high-precision microscope table. The ability to perform seamless back-and-forth multi-scale imaging comes from a strict registering of image coordinates.
Optimizing Plasmonic Microarray Biosensors: Custom Optical System for Enhanced Evaluation and Characterization
Authors: Csőke Lóránt Tibor , Csáki Andrea , Kollár Zsolt
Published: October 2024

This paper presents the design and implementation of a tailored optical system for rapid characterization of transmission-based localized surface plasmon resonance (LSPR) biosensors. The system incorporates a motorized monochromator, offering extreme versatility in experimenting with wavelength resolution and bandwidth of the illumination. This setup streamlines the process of determining optimal chip design parameters such as the density of nanoparticles and the number of detection wavelengths required, as measurements are fully automated and software-driven. Furthermore, the system facilitates straightforward detection of manufacturing errors, including misaligned spots or inhomogeneous particle distribution, enhancing overall efficiency and reliability in biosensor evaluation.
s2ISM: A Comprehensive Approach for Uncompromised Super-Resolution and Optical Sectioning in Image Scanning Microscopy
Authors: Zunino Alessandro , Garrè Giacomo , Perego Eleonora , Zappone Sabrina , Donato Mattia , Vicidomini Giuseppe
Published: October 2024

Image Scanning Microscopy (ISM) enables good signal-to-noise ratio (SNR), super-resolution and high information content imaging by leveraging array detection in a laser-scanning architecture. However, the SNR is still limited by the size of the detector, which is conventionally small to avoid collecting out-of-focus light. Nonetheless, the ISM dataset inherently contains the axial information of the fluorescence emitters. We leverage this knowledge to achieve computational optical sectioning without sacrificing the conventional benefits of ISM. We invert the physical model to fuse the raw dataset into a single image with improved sampling, SNR. lateral resolution, and optical sectioning. We provide a complete theoretical framework and validate our approach with experimental images of biological samples acquired with a custom setup equipped with a single photon avalanche diode (SPAD) array detector. Furthermore, we generalize our method to other imaging techniques, such as multi-photon excitation fluorescence microscopy and fluoresce lifetime imaging. To enable this latter, we take advantage of the single-photon timing ability of SPAD arrays, accessing additional sample information. Our method outperforms conventional reconstruction techniques and opens new perspectives for exploring the unique spatio-temporal information provided by SPAD array detectors.
Towards enhanced cancer therapy; Leveraging bioresorbable optical fibers for improved treatment outcomes
Authors: Pandayil Jawad T. , Šušnjar Stefan , Cortese Lorenzo , Boetti Nadia G. , Swartling Johannes , Janner Davide , Durduran Turgut
Published: October 2024

Bioresorbable photonic implants are emerging as potential material choice for interstitial theranostic and monitoring applications. They gradually dissolve within the physiological environment in a clinically relevant period, eliminating the need for extraction surgeries. In the present study, we tested the suitability of in-house fabricated bioresorbable optical fibres based on calcium phosphate (CaP) glass for diffuse correlation spectroscopic (DCS) and diffuse fluorescence tomographic (DFT) applications. The results represent the potential of bioresorbable fibers for the monitoring of interstitial microvascular blood flow and the spatial distribution of fluorescent photosensitizer drugs that are administered prior to therapies. Together or separate, the continuous monitoring of these parameters can have significant implications in planning, optimizing and in predicting or monitoring the outcomes in interstitial photodynamic therapy (PDT).
Derivative-free optimization for optical chirality enhancement
Authors: Pellegrini Giovanni , Michelotti Francesco , Occhicone Agostino , Celebrano Michele , Finazzi Marco , Biagioni Paolo
Published: October 2024

We adopt a multi-objective optimization approach to design one-dimensional photonic crystals with large optical chirality enhancements. We show that this technique allows for a large design flexibility in terms of selected materials and operational wavelengths. Finally, we demonstrate that the designed platforms provide state of the art chirality enhancements above the two orders of magnitude over arbitrarily large areas and broad spectral ranges.
Framework for canonical quantum plasmonics for finite structure in three dimensions
Authors: Semin Georgii , Jauslin Hans-Rudolf , Guérin Stéphane
Published: October 2024

We provide the framework and the tools for canonical quantization of plasmon polaritons from metallic or dielectric finite nanostructures. They allow one to diagonalize the Hamiltonian and to exactly determine the quantized electromagnetic field and an imaginary Green’s tensor identity satisfying the Sommerfeld radiation boundary conditions.
Solid state dewetting of semiconductor thin films: From fundamental studies to photonic applications
Authors: Freddi Sonia , Gherardi Michele , Granchi Nicoletta , Sfuncia Gianfranco , Nicotra Giuseppe , Brescia Arianna , Fedorov Alexey , Vincenti Maria Antonietta , Abbarchi Marco , Intonti Francesca , Bollani Monica
Published: October 2024

Here we propose to exploit the natural instability of thin solid films, i.e. solid state dewetting, to form regular patterns of monocrystalline atomically smooth Si, Si1-xGex and Ge nanostructures that cannot be realized with conventional methods. Additionally, the solid-state dewetting dynamics is guided by pre-patterning the sample by a combination of electron-beam lithography and reactive-ion etching, obtaining precise control over number, size, shape, and relative position of the final structures. Methods and structures will be optimized towards their exploitation mainly in photonic devices application (e.g. anti-reflection coatings, colour-filters, random lasers, quantum emitters and photonic sensors).
All-plastics distributed Bragg reflectors for sensing and thermal shielding applications
Authors: Lanfranchi Andrea , Martusciello Martina , Megahd Heba , Escher Andrea , Lova Paola , Comoretto Davide
Published: October 2024

Year by year, the importance of plastic nanostructures in photonics is increasing. Indeed, polymers represent an interesting alternative to more traditional metal oxides, being easily processable and allowing for light, free-standing and flexible structures. In the field of energy efficiency and sustainability, we bring in two positive examples of the use of plastic photonic crystals: sensing and thermal shielding. In sensing they allow for easy detection of analytes, such as the byproducts of food degradation; a colour change identifies the spoilage, with possible application of these plastic sensors in smart packaging applications. On the other hand, they can be of interest for thermal shielding applications. Indeed, they can be engineered as thin, transparent films able to reduce indoor heating by sunlight and in turn the energy consumption related to the use of air conditioning.
Fast thickness mapping of large-area exfoliated two-dimensional transition metal dichalcogenides by imaging spectroscopic ellipsometry
Authors: Peci Ermes , Petrini Nicolò , Curreli Nicola , Spotorno Emma , Kazemi Tofighi Nastaran , Magnozzi Michele , Scotognella Francesco , Kriegel Ilka , Bisio Francesco
Published: October 2024

Two-dimensional transition metal dichalcogenides (2D TMDCs) have gained significant attention from the scientific community due to their exceptional properties, making them extremely attractive for optoelectronic and photonic applications. However, many exfoliation or synthesis techniques yield 2D crystals with limited crystalline quality and/or small lateral size. Here, we report a facile Au-assisted exfoliation method, yielding high-quality, large-area monolayers with lateral sizes of hundreds of micrometers. A self-assembled monolayer of (3-aminopropyl)triethoxysilane (APTES) is employed to improve the adhesion between the 2D material and the target substrate, dramatically improving the yield and reliability of the exfoliation process. The monolayer nature of the final sample is then assessed by means of Imaging Spectroscopic Ellipsometry (iSE), which enables a quick and reliable thickness mapping over millimeter-sized areas.
Multi-target Pulsed Laser Deposition (PLD) Technique for the growth of μm-to-nm scale Photo-active Thin-film Coatings
Authors: Kumi-Barimah E , Loganathan Sarath Kumar , Sharma Geeta , Jha Animesh
Published: October 2024

There has been an unprecedented increase in the growth of photonic components over the last 25 years based on different photonic materials; each having structural/functional limitation in integrated devices. The challenge is that the semiconductors are grown inside MBE chambers, whereas the polymeric waveguides are fabricated by spin-coating. By comparison, glass and crystal-based materials are processed via sputtering and sol-gel techniques. None of these materials processing techniques, therefore, are compatible for a single-step device fabrication, due to the incompatibilities of chemical and physical properties of individual materials. A solution for overcoming the materials limitation is to develop a multi-materials deposition chamber which allows sequential/heterostructure growth on a substrate, without compromising the structural, spectroscopic, and device performances. The rare-earth-ion doped glass- and crystal-based devices are pumped with semiconductor lasers, suggesting that the glass-semiconductor devices might perform better when structurally integrated which may also help in reducing the pump-power for achieving efficient population inversion. We explain the applications of PLD for controlling the structure of thin-films grown on inorganic and metallic substrates for photonic device and photo-active coatings for biological applications, respectively. Examples of materials deposited on dissimilar substrates are discussed with applications such as photonic devices and photo-bioactive surfaces for sensing.
Rapid thermal annealing of chalcogenide thin films for mid-infrared sensing and nonlinear photonics
Authors: Halenkovič Tomáš , Gutwirth Jan , Šlang Stanislav , Chahal Radwan , Hammouti Abdelali , Charrier Joel , Němec Petr , Nazabal Virginie
Published: October 2024

The influence of rapid thermal annealing (RTA) onto chalcogenide Ge-Sb-Se thin films is reported, focusing on changes in optical properties. These materials possess broad mid-infrared transparency covering the most critical absorption bands for (bio)chemical sensing and high third-order optical nonlinearities for potential applications in nonlinear photonics. The parameters of the RTA process within this study include the annealing temperature, heating rate, and the two sample processing methods – one by placing the sample inside the graphite susceptor and the other by simply laying the sample onto the silicon wafer. Selenide thin films were found to undergo a shift of the absorption edge upon the RTA, resulting in an optical bandgap energy increase (bleaching effect) and a notable refractive index decrease. As a result of structural relaxation, such changes show a great potential of RTA in fine-tuning of optical performance of chalcogenide thin films and planar chalcogenide waveguides. The authors acknowledge the IBAIA (101092723) Horizon Europe project, the ANR AQUAE (ANR-21-CE04-0011-04) project of the French National Research Agency (ANR), and project No. 22-05179S of the Czech Science Foundation (GAČR) for financial support.
Visualization of inhomogeneities in Ti:Sapphire laser medium
Authors: Miller Vojtěch , Žídek Karel
Published: October 2024

This work presents innovative methods for visualizing inhomogeneities and stress distributions in Ti:Sa (titanium-doped sapphire) crystals, which are challenging to assess due to their birefringent nature. Two experimental approaches were developed: the first enables two-dimensional mapping of the Figure of Merit (FoM) and absorption at wavelengths of 532 nm, 780 nm, and 1550 nm, revealing variations in absorption across the crystal. The second experiment utilizes circularly polarized light and polarization imaging to detect internal stress and defects. The results demonstrate the successful visualization of lateral absorption, stress, and core features within the crystals, offering insights into their optical quality. These techniques provide new possibility for evaluation of laser materials, with significant implications for improving the manufacturing and selection processes of Ti:Sa crystals in advanced laser applications.
Comparative study on fluoride fibers for mid-infrared generation pumped by a Cr:ZnS oscillator
Authors: Szewczyk Olga , Kowalczyk Maciej
Published: October 2024

We demonstrate a comparative study on single-mode fluoride fibers for mid-IR generation. We took into consideration examples of ZBLAN fibers from all leading manufacturers. The fluoride fibers were pumped with the 30-fs pulses from a Cr:ZnS oscillator which allowed for Raman soliton generation up to 4 μm and supercontinuum generation up to 5.3 μm.
Design of nonlinear pulse shaper for flexible repetition rate ultrashort pulse generation
Authors: Närhi Mikko , Ranne Katariina , Gumenyuk Regina
Published: October 2024

Nonlinear pulse shaping based on Mamyshev regenerator is a powerful approach for ultrashort pulse generation. The performance strongly depends on the initial seed parameters. We investigate and design a nonlinear pulse shaper seeded by a long pulsed gain-switched laser diode for generation of high quality ultrashort pulses with flexible repetition rate. The shaper architecture provides more flexibility on the input diode requirements and can yield shorter pulses with the improved laser relative intensity noise. The system optimization is based on numerical simulations mapping the favourable parameters at each stage of the system and enabling identification of limiting factors.
Energy stability in multi-timescale pump-probe spectroscopy with free-running lasers (ADASOPS)
Authors: Antonucci Laura , Solinas Xavier , Bonvalet Adeline , Joffre Manuel
Published: October 2024

ADASOPS pump-probe spectroscopy is a multi-timescale technique that is spreading rapidly especially in the field of biomolecule dynamics. Based on slight variations of the laser repetition rate, it is simple to implement and can cover a time range extending from a hundred femtoseconds to a millisecond or more. We have studied the energy fluctuations associated with this approach and have proposed a method for overcoming any instabilities.
Photonic Orbital Angular Momentum for quantum interplaying with atoms and entanglement
Authors: Pruvost Laurence
Published: October 2024

Photonic Orbital Angular Momentum (OAM) is becoming a pertinent quantum variable for atom-light interaction, in particular for non-linear interaction which leads to photon entanglement and OAM-entanglement. With two 4-levels atomic schemes, we show that Four Wave Mixing addressed by vortex beams leads to very different OAM-entanglement especially for large OAM values.
Secure communication based on sensing of undetected photons
Authors: Sternberg Jean , Voisin Julien , Roux Charline , Chassagneux Yannick , Amanti Maria
Published: October 2024

In this paper, we introduce a secure optical communication protocol that harnesses quantum correlation within entangled photon pairs. A message written by acting on one of the photons can be read by measuring exclusively the other photon of the pair. In this scheme, a bright, meaningless optical beam hides the message, rendering it inaccessible to potential eavesdroppers. Unlike traditional methods, our approach only affects unauthorized users, fundamentally limiting their access to the communication channel. We demonstrate the effectiveness of our protocol by achieving secure communication through both amplitude and phase modulation, relying on single-photon measurements, as opposed to most approaches which rely on coincidence measurements. We successfully demonstrate the resilience of the data transfer to noise up to 105 times greater than the signal, and we employ this technique for the secure transfer of an image.
Image denoising based on Singular-Spectrum-Analysis (SSA) in femtosecond stimulated Raman scattering microscopy
Authors: Costa Giovanni , Ranjan Rajeev , Ferrara Maria Antonietta , Sansone Mario , Sirleto Luigi
Published: October 2024

Stimulated Raman scattering (SRS) microscopy is able to perform high sensitivity biological imaging with high spatial and spectral resolution and image acquisition time of a few seconds. Nevertheless, SRS images often suffer from low SNR, due to the weak Raman cross-section of biomolecules. Therefore, methods aiming to improve image quality are mandatory. In this paper, the performances of a 2D denoising algorithm based on SSA is analysed. SRS imaging of lipids droplets have been used in order to validate our algorithms.
Detection of microplastics and nanoplastics: Are Raman tweezers and enhanced Raman methods the solution for sub 20 μm particles?
Authors: Bernatova Silvie , Foti Antonino , Kizovsky Martin , Donato Maria , Marago Onofrio , Magazzu Alessandro , Jezek Jan , Zemanek Pavel , Giuseppe Gucciardi Pietro
Published: October 2024

Despite the significant progress in the detection of nano and small microplastics, the detection of such particles still faces problems caused by the limitations of current detection methods and instruments. Herein, we present the optical methods for detection of sub 20 μm microplastics. We introduce optical methods for the analysis of individual microplastics and the fabrication of a substrate using plasmonic particles to detect plastic nanoparticles. We summarize recent experimental activities involving the construction of portable Raman tweezers that can be used for optical trapping and analysis of microplastics with size from a few hundred nanometers to lower tens of micrometers. Optical trapping is complemented by another optical manipulation method: nanoimprinting of plasmonic nanoparticles that enables create the “active” aggregates that can be used for Surface Enhanced Raman Spectroscopy (SERS) detection in microfluidic circuits and as plasmon-enhanced thermoplasmonic concentrators for nanoscale particulate matter such as nanoplastics. The principle of nanoimprinting is based on the dominance of the scattering force (compared to the gradient force) for plasmonic particles, this force pushes the particles in the direction of propagation of the light beam. This phenomenon enables the preparation of an aggregate comprising of plasmonic particles that can serve as a substrate for SERS and as a source of the temperature gradient that is able to attract dielectric nanoparticles. In both cases, enhanced sensitivity is demonstrated, allowing the detection of nanoplastics/molecules of size/concentration orders of magnitude lower than what can be achieved by Raman spectroscopy. This study demonstrates that the combination of two optical manipulation techniques with Raman spectroscopy is capable of filling the technological gap in the detection of plastic particles ranging in size from a few tens of nanometers to 20 micrometers. This is an ideal solution for the detection of very small microplastics, which currently lacks a suitable technology.
Laser-assisted micromachining: An innovative tool for advancing the multifunctional optofluidic lab-on-a-chip
Authors: Criante Luigino
Published: October 2024

Ultrafast laser micromachining is a technological innovation with exciting potential for many applications and has led to impressive advances in the study of light-matter interactions. In this context, the laser-assisted wet etching fabrication technique has opened new frontiers in the optofluidic lab-on-a-chip, i.e. complex and easy-to-use microsystems capable of integrating multiple physicochemical processes on a single platform to replicate specific chemical, biological and medical tests typically performed in a laboratory. These miniaturised multifunctional laboratories exploit the synergy between the high sensitivity of optics and the unique ability to manipulate small quantities of microfluidics to develop a new frontier of analytical devices. The chips can be manufactured in monolithic 3D versions with no geometric constraints and are fully embedded in the substrate (typically fused silica). In addition to the advantage of using an inert substrate (strategic for biological applications), the elimination of the sealing step and the high mechanical strength offer numerous advantages. To demonstrate the potential of this new sensing platform, we report on the benefits of integrating in-plane 3D micro-optics to increase the S/N in-chip spectroscopic analysis in two case studies: flow cytometer devices and innovative chips for real-time Raman analysis of bio-samples in flow, even non-transparent ones.
Characterization of Kuwait Crude Oil via Terahertz Fourier Transform Spectroscopy
Authors: Salonga Ponseca Carlito Jr. , Al-Shamali Mustafa , Karaliunas Mindaugas , Villarde Jezlor , Rabaja Ophel Eliza , Jison Andgrel Heber , Pido John Robert , Kašalynas Irmantas
Published: October 2024

We report the experimental and theoretical terahertz (THz) absorption characteristics of unprocessed crude oils from Kuwait oil wells. Using THz Fourier transform spectroscopy technique and semi-empirical computational chemistry calculation, five of the 30 crude oils revealed characteristic absorbance spectra. Experimental data showed absorption peaks at 6.0 THz, 7.7 THz, 13 THz, and 16 THz. On the other hand, the calculated spectral bands of 10 nonane molecules were found at around 2.8 THz, 7.7 THz, 10 THz, and 16 THz. Although only two bands were predicted by the calculation, adding alkane molecules of different lengths (pentane to decane) resulted in the formation of new bands. These preliminary results suggest that there is a mixture of different alkanes present in the investigated samples, a typical characteristic of unprocessed crude oil.
Femtosecond laser ablation of 3D-printed PCL Scaffolds as a strategy to enhance bone tissue regeneration efficacy
Authors: Radziunas-Salinas Yago , Carnero Bastián , Pita-Vilar María , Aboal-Castro Lucía , Díaz-Gómez Luis Antonio , Flores-Arias María Teresa
Published: October 2024

New photonic techniques need to be developed to improve personalised medicine methods in tissue engineering. In the case of severe bone injuries, difficulties arise when creating platforms where cells required to be efficiently adhered. Femtosecond laser ablation appears as a versatile technique for modifying the surface of materials with high precision and neat outcomes. Thus, a strategy combining 3D printing of biopolymeric scaffolds and femtosecond laser ablation is proposed to design a device with enhanced material properties in terms of cell growth for bone tissue regeneration. Three different patterns were proposed, and it was proven that cell adhesion improvements rely on the pattern profile, assessing that grooved scaffold successfully increased cell adhesion and proliferation in comparison with micropitted samples.
Glucose concentration detection using a low-cost Raman Spectroscopy Kit
Authors: Cunha Cristina , Silva Susana , Frazão Orlando , Novais Susana
Published: October 2024

Raman technology offers a cutting-edge approach to measuring glucose solutions, providing precise and non-invasive analysis. By probing the vibrational energy levels of molecular bonds, Raman technology generates a unique spectral fingerprint that allows for the accurate determination of glucose concentrations. This study proposes the use of Raman spectroscopy to identify different glucose concentrations through the detection of Raman fingerprints. As expected, higher concentrations of glucose in the solution conducted to higher peak bands, indicating more glucose molecules interacting with light and consequently increasing the magnitude of inelastic scattering. This non-destructive approach preserves sample integrity and facilitates rapid analysis, making it suitable for various applications in biomedical research, pharmaceutical development, and food science.
Label-free scattering snapshot classification for living cell identification
Authors: Dannhauser David , Netti Paolo Antonio , Causa Filippo
Published: October 2024

A scattering snapshot hold an enormous potential for cell class and state classification, allowing to avoid costly fluorescence labelling. Beside convolutional neural networks show outstanding image classification performance compared to other state-of-the-art methods, regarding accuracy and speed. Therefore, we combined the two techniques (Light Scattering and Deep Learning) to identify living cells with high precision. Neural Networks show high prediction performance for known classes but struggles when unknown classes need to be identified. In such a scenario no prior knowledge of the unknown cell class can be used for the model training, which inevitably results in a misclassification. To overcome the hurdle, of identifying unknown cell classes, we must first define an in-distribution of known snapshots to afterwards detect out of distribution snapshots as unknowns. Ones, such a new cell class is identified, we can retrain our cell classifier with the obtained knowledge, so we dynamically update the cell class database. We applied this measurement approach to scattering pattern snapshots of different classes of living cells. Our outcome shows a precise cell classification, which can be applied to a wide range of single cell classification approaches.
Low Coherence Interferometry Measurement: An Algorithm for fast processing with low noise and phase linearisation
Authors: Robalinho Paulo , Rodrigues A. , Novais S. , Ribeiro A. B. Lobo , Silva S. , Frazão O.
Published: October 2024

This work proposes a signal processing algorithm to analyse the optical signal from a Low Coherence Interferometric (LCI) system. The system uses a Mach-Zehnder (MZ) interferometer to interrogate a Fabry-Perot cavity, working as an optical sensor. This algorithm is based on the correlation and convolution operations, which allows the signal to be reconstructed based on itself, as well as, on the linearization of the signal phase, allowing the non-linearities of the actuator incorporated on the MZ interferometer to be compensated. The results show a noise reduction of 30 dB in the signal acquired. As a result, a reduction of 8.2 dB in the uncertainty of the measurement of the physical measurand is achieved. It is also demonstrated that the phase linearization made it possible to obtain a coefficient of determination (namely, R-squared) higher than 0.999.
Photoinduced birefringence in azopolymers measured at 1550 nm
Authors: Soares Beatriz , Silva Susana , Ribeiro Paulo , Frazão Orlando
Published: October 2024

Azobenzenes are a class of compounds presenting photoisomerization capabilities that allow the writing and erasure of birefringence along a desired direction. This feature enables applications requiring polarization control, which although have been extensively investigated in the visible light spectrum, poor emphasis has been paid to the infrared region. In this paper, a systematic characterization of induced birefringence creation and relaxation dynamics has been carried out in azopolymers thin films in the infrared telecommunications region of 1550 nm. This study covers both birefringence characterization in terms of wavelength and irradiance of birefringence writing beams. Preliminary results revealed remarkable maximum birefringence values as high as 0.0465 attained during the recording phase, that stabilized at 0.0424 during the relaxation phase, which is quite promising for many applications.
Generalized angle-orbital-angular-momentum Talbot effect
Authors: Fickler Robert
Published: October 2024

Light containing twisted phase structures, i.e. light carrying orbital angular momenta (OAM), when propagating inside ring-core fibres leads to a complex interference dynamics resulting in the fundamental self-imaging phenomenon known as the Talbot effect in the angular domain. We study the effect in the classical and quantum optics domain and show that it can be used to implement higher-order beams splitters. Interestingly, such beam splitting operations become more compact the higher the splitting ratio. In addition, we show that a similar self-imaging effect appears for whispering gallery modes carrying OAM in step-index multi-mode fibres, which enables the application of the angular Talbot effect in off-the-shelf components. Finally, we extend the study of the angular Talbot effect through combing it with its Fourier-analogue, i.e. the Talbot effect in orbital angular momentum space. Thereby we implement the generalized angle-orbital-angular-momentum Talbot effect, which enables full control over the angular intensity distribution as well as the OAM spectrum of the light field. Moreover, the complex self-imaging dynamics can be used to sort OAM light fields, in principle, without any crosstalk and, thus, can be seen a promising method for OAM multiplexing schemes.
Kerr frequency comb generation in fiber Fabry-Pérot resonator: Technological locks and leveraging fiber properties
Authors: Bourcier Germain , Mohand Ousaid Safia , Balac Stéphane , Lumeau Julien , Moreau Antonin , Bunel Thomas , Conforti Matteo , Mussot Arnaud , Fernandez Arnaud , Llopis Olivier
Published: October 2024

We explore fiber Fabry-Pérot (FFP) resonators, a new platform for frequency comb generation We experimentally identified mirror diffraction losses dependent on the effective area of the fiber and simulated them via Fourier optics. In the nonlinear regime, a linear stability analysis of a generalized Lugiato-Lefever equation revealed optimization of reflectivity and detuning, leading to a significant reduction in the required power threshold for comb generation compared to linear regime, and to improved energy frugality. Furthermore, controlled or exploited birefringence in various experimental settings enabled the generation of Kerr frequency combs and stimulated Brillouin lasers. In this communication we propose an overview of the practical characteristics related to the fabrication and use of these resonators.
Photonic emergent Learning
Authors: Leonetti Marco , Gosti Giorgio , Ruocco Giancarlo
Published: October 2024

Disordered, self-assembled media, contain a large amount of information, which can be seen as a huge set of random and uncontrolled memory patterns. In the framework of optics, in which an opaque medium may modelled with the transmission matrix approach, each transmitted mode “contains” a memory element which is embodied by the correspondent transmission vector. Even if the stored amount of information in this system is huge, these random memories cannot be tailored easily. Here we present a new approach to write, read, and classify memory patterns: the photonic emergent learning. The writing paradigm is borrowed form a-physical- mathematical model for the biological memory, the emergent archetype, which we translated to photonics. In our approach the random patterns enclosed in the transmitted electromagnetic modes, are used as prototypes which are summed in constructive fashion in order write our target archetype-memory into our disordered optical memory (DOM). The DOM can work as a content addressable memory, retrieving at the lightning speed which memory in the library is the closest to an optically proposed query pattern. Moreover, the optical memories can be organized into super structures containing memories of the same thus efficiently delivering a classification task.
Research on Unfair Competition in the Digital Economy: Innovation, Regulation, and Balancing Strategies
Authors: Kang Yuhao
Published: October 2024

Online unfair competition is on the rise, disrupting market order and violating consumer rights in the context of the fast developing digital economy. Therefore, the purpose of this essay is to investigate the nature and forms of unfair competition in the internet economy and how it affects innovation. In addition, it examines the shortcomings of the existing regulatory frameworks and suggests balanced approaches and effective techniques to encourage the digital economy's healthy expansion. Defamation, misleading advertising, and web crawlers are common examples of unfair competition on the Internet. Another kind of unfair competition is data mining, which involves acquiring rivals' customer information or trade secrets. These behaviors not only undermine the principle of fair competition in the market but also mislead consumers and harm their interests. There is a certain relationship between unfair competition on the Internet and innovation. On the one hand, unfair competition on the Internet may stem from companies' excessive pursuit of innovation. To stand out in fierce market competition, companies may resort to unfair means to gain competitive advantages. On the other hand, unfair competition on the Internet may also inhibit innovation, as companies may reduce their innovation investment due to concerns about competitors taking unfair measures. The current regulatory mechanism has certain shortcomings in addressing unfair competition behavior on the Internet. On the other hand, the regulatory mechanism's definition of unfair competition on the Internet is not clear enough, which makes it difficult for regulatory agencies to accurately judge and handle it in the law enforcement process. At the same time, the regulatory mechanism's punishment for unfair competition on the Internet is not strong enough to effectively deter illegal behavior. To address unfair competition on the Internet, it is necessary to establish effective regulatory mechanisms and balance measures. Firstly, it is necessary to clarify the definition of unfair competition on the Internet and establish specific regulatory rules and standards. Secondly, it is necessary to strengthen the enforcement efforts of regulatory agencies, increase the severity of penalties, and ensure the effectiveness of regulatory mechanisms. At the same time, it is also necessary to strengthen corporate self-discipline, promote compliance with market rules, and jointly maintain market order. In short, unfair competition on the Internet has had a negative impact on the development of the digital economy, and it is necessary to establish effective regulatory mechanisms and balance measures to promote the healthy development of the digital economy.
Fan Culture of Urban Communication: Exploring Urban Branding Through Social Platforms
Authors: Huang Luanqian
Published: October 2024

Under the background of the rapid development of new media technology, the cultural development between cities has become increasingly important. At present, the development of digital media has spawned a new form different from the traditional fan culture. With the widespread use of social media platforms, fan culture and live broadcasting industry play a crucial role in shaping urban brands and enhancing urban competitiveness. Based on this background, this paper will conduct a comprehensive analysis of urban culture through literature research and summary, conduct quantitative research and platform content analysis, and study the influence of fan culture on the construction of urban brands through social media.
Research on the Application of Consumer Behavior Theory in the Innovation of Health Management Services
Authors: Li Xia
Published: October 2024

The irrational expression of consumer behavior in the field of health management services can easily trigger a crisis of trust, posing a serious challenge to creating a healthy consumption environment. The article takes the irrational expression of consumer behavior as the research object and sorts out its basic manifestations and characteristics in health management services. After an in-depth analysis of the emotional presentation and formation reasons for the irrational expression of consumer behavior, this article proposes that strategies to address irrational expression of consumer behavior should start from four directions: data-driven monitoring, multi-party participation in agenda setting, institutional construction, and cultural guidance, to promote the rational and healthy development of a healthy consumption environment.
Factors Influencing Consumer Purchasing Decision Behavior: A Case Study of Starbucks
Authors: Zhang Chen
Published: October 2024

By analyzing the influencing factors of consumer purchasing decision-making behavior, brand enterprises can gain a deeper understanding of consumers' purchasing needs, thereby better formulating and developing marketing strategies. This article defines consumer purchasing decision behavior and points out that the notification of consumer purchasing behavior under the current new situation includes strong information collection ability, personalized consumption presentation, and high consumer initiative. Taking Starbucks as a case study, the influencing factors of consumer purchasing decision behavior are analyzed. They are economic factors, social factors, organizational factors, and individual factors, and targeted marketing strategies for enterprises under the new situation are proposed, including strengthening brand image construction, improving product personality level, enhancing online marketing capabilities, and cultivating professional marketing teams.
Evaluation of the Effectiveness of Bioeconomy Policies Based on Qualitative Comparative Analysis
Authors: He Yahan
Published: October 2024

As an important driving force for the development of the bioeconomy, bioeconomy policies are of great importance in promoting the transfer and application of qualitative comparative analysis (QCA) concepts in the field of bioeconomy. Moreover, QCA has become a key theory and a critical tool for assessing the effectiveness of bioeconomy policies. Through the analysis of QCA method, the author proposes a strategy for evaluating bioeconomy policy research by identifying relevant policies and influencing factors. In addition, it attempts to present a possible integration pathway between quantitative comparative analysis (QCA) and bioeconomy policy, providing a new approach for the evaluation of bioeconomy policy effectiveness and innovation.
Research on Personalized Marketing Strategy of Financial Products Based on Big Data
Authors: Ma Yinye
Published: October 2024

With the rapid development of information technology, big data has become one of the most important tools for personalized marketing in the financial industry. Based on big data analysis, this study investigates the practice and impact of personalized marketing strategies for financial products in the current economic environment. Financial institutions can create customer portraits and tailored products and services by gathering and studying data on consumers' buying patterns, behavioral preferences, social circles, and interactive feedback. Using various methods, including case studies, in-depth interviews, and quantitative analysis, we took a closer look at how big data can help financial institutions improve marketing efficiency, optimize product design, increase customer satisfaction, and improve customer loyalty. Research shows that big data can greatly support the marketing of financial products, improving market segmentation, providing better opportunities for cross-selling and value-added services, and optimizing marketing resources through predictive analytics, instant marketing, and highly personalized customer experiences. Nonetheless, financial institutions must demonstrate effective skills in managing data, using analysis technology, protecting privacy, and implementing personalized marketing strategies to fully benefit from these advantages.
Application and Analysis of Social Media Data in Economic Research
Authors: Wang Meiyang
Published: October 2024

As Internet technology enters a new era, social media has become an essential platform for people to obtain information and express their views, which has profoundly impacted economic research. This paper focuses on the application of social media data in economic research. First, this paper analyzes the essential performance and characteristics of social media data, such as user engagement, the speed of information diffusion, and content diversity. Second, it explores the expression of emotions on social media, including immediate reactions to economic events, analysis of the acceptability of economic policies, and the social psychology of economic issues. In addition, we analyze the reasons why social media data affects the economy, including the recommendation mechanism of algorithms, changes in social phenomena due to economic globalization, economic inequality and differentiation of public opinion among social classes, and distortion of economic opinions caused by information bubbles. Finally, we propose strategies to prevent social media data bias, including data cleaning and analysis, multi-dimensional information integration strategies, laws, regulations and technical measures, and education guidance. This paper aims to provide a comprehensive framework for analyzing social media data for economic research so as to promote the high- quality development of economic research.
The Influence and Research of Traditional Culture on Economic Development
Authors: Zhang Jiaxuan
Published: October 2024

This article explores in depth the impact and mechanism of traditional culture on economic development. Firstly, the article offers an in-depth examination of traditional culture, addressing its definition, characteristics, and significance. It discusses various forms of expression and highlights the societal value and functions of traditional culture. Secondly, the research focuses on the mechanism by which traditional culture influences economic development, including shaping economic behavior, influencing economic decision-making, and driving economic innovation. Also covered in the piece is the ever-changing relationship between traditional culture and economic progress, looking at both the ways in which one might affect the other. According to it, both may live in peace with one other. In addition, the article lays out a series of steps for incorporating traditional culture into economic development in a way that benefits both parties. These steps include ensuring the culture’s survival and passing it on to future generations, as well as incorporating it into the modern economy.
Research on Innovation in Human Resource Management in the Context of a Sustainable Economy
Authors: Chen Xi
Published: October 2024

Human resource management (HRM) is encountering fresh challenges and possibilities in the sustainable economy. As the world’s attention on environmental protection and social responsibility grows, businesses are reassessing their human resource management strategies and practices to support sustainable development. The innovative human resource management model helps improve employee satisfaction and loyalty and enhances enterprises’ competitiveness and market adaptability. First, businesses must focus on green recruitment by setting standards that prioritize environmental protection and social responsibility to attract talents that are aligned with sustainable development principles. This method not only enhances the company’s reputation but also fosters the sustainable advancement of society. Second, companies can introduce flexible working arrangements, such as telecommuting and flexible working hours, to meet employees’ needs for environmental protection and work-life balance. Furthermore, the organization should prioritize its workforce’s ongoing education and growth. It entails enhancing employees’ understanding and abilities in environmental protection and sustainable practices through comprehensive training programs and fostering an environment that encourages innovation. It is necessary for enterprises to establish an effective performance management system, incorporate sustainable development goals into employee performance appraisal, and ensure that employees will contribute to the sustainable strategy. Implementing the aforementioned innovative management measures allows enterprises to achieve enhanced economic benefits while positively contributing to the sustainable development of society and the environment.