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Summary: Multifunctional micro- and nanoparticles have found their applications in fields like medicine, display materials, cosmetics, and so on. Advances in these fields have been demonstrated to need scalable uniformly sized, mass-produced, and structured spherical particles. In this work, we proposed structure-tailored and multifunctional composite polymeric microspheres with tunable diameter size, by using a versatile and scalable in-fiber particle fabrication through the Plateau-Rayleigh capillary instability method. The results show that the characteristic shapes of the luminescence spectra of CsPbBr3 remained similar before and after embedding in the microspheres. The luminescence intensity was stabilized at 85–90% of their original photoluminescence intensities over an extended period. Moreover, the photoluminescence lifetime of the fluorescent microspheres was increased by 9.03% compared to CsPbBr3. The X-ray diffraction results revealed that there was no change in the crystal structure of the dopants before and after the encapsulation. Also, precise magnetic manipulation of Janus microspheres was successfully demonstrated.

In this article, the (2+1)-dimensional nonlinear hyperbolic Schrödinger model is studied analytically which specifies the proliferation of optics signal in single-mode fiber optics by using the unified technique, the exp(- δ (ζ) ) technique and the polynomial expansion technique. These techniques can give solutions of different kind that has application in physical mathematical fields, optical wave structure, and many other fields that are related to wave transmission. As compared to other approaches these used methodology are effective, unique, and easy to applicable for solving the complex models in Physics. The waveform in electromagnetic domains topics are discussed using this model as a governing equation. For a given set of pertinent parameters, the dynamics of various wave structures are visualised in 3D, 2D, and contour using Mathematica. These solutions exhibit singular periodic, multi-periodic, optical, singular and multiple bell-shaped, and μ-shaped solitons solutions as their behaviour. Further we study the stability and modulation instability (MI), also some plots are drawn for better understanding of solution. The solutions derived from the utilized techniques describe that these approches are easy, potent and uncomplicated, and these can be applicable for solving many other NLSE in Mathematical physics, and also in different field of natural sciences. The solution obtain are newly made because according to my best knowledge these methodology are not applied to this model in previous. [ABSTRACT FROM AUTHOR]

Summary: The analysis of salivary biomarkers as expression of periodontal health conditions has been proposed as a useful aid to conventional diagnostic approaches. In this study, we present a point-of-care test (POCT) exploiting a surface plasmon resonance (SPR)-based optical biosensor to detect salivary macrophage inflammatory protein (MIP)-1α, a promising marker of periodontitis. A plastic optical fiber (POF) was suitably modified and functionalized by an antibody self-assembled monolayer against MIP-1α for plasmonic detection. The proposed SPR-POF biosensor showed high selectivity and very low limit of detection for MIP-1α of 129 fM (1.0 pg/mL) in phosphate-buffered saline and 346 fM (2.7 pg/mL) in saliva. As a proof of concept, this POCT was also able to discriminate between a periodontitis patient and a healthy subject. The obtained results support the future application of this technology for an on-site detection and real-time monitoring of periodontal health conditions for diagnostic and therapeutic purposes.

Summary: The prevalence of sleep disorders has increased because of the fast-paced and stressful modern lifestyle, negatively impacting the quality of human life and work efficiency. It is crucial to address sleep problems. However, the current practice of diagnosing sleep disorders using polysomnography (PSG) has limitations such as complexity, large equipment, and low portability, hindering its practicality for daily use. To overcome these challenges, in this article an optical fiber sensor is proposed as a viable solution for sleep monitoring. This device offers benefits like low power consumption, non-invasiveness, absence of interference, and real-time health monitoring. We introduce the sensor with an optical fiber interferometer to capture ballistocardiography (BCG) and electrocardiogram (ECG) signals from the human body. Furthermore, a new machine learning method is proposed for sleep condition detection. Experimental results demonstrate the superior performance of this architecture and the proposed model in monitoring and assessing sleep quality.

The paper presents an innovative experimental setup that can show the wave–particle duality of light. A new experimental class for teaching light wave–particle duality concept based on the presented setup is also designed for undergraduates who major in Optics. Based on optical radiation pressure theory, the three-dimensional space trapping, localization, and movement of the particles reveal the particle property of light. Based on the beam interferometry technology, the recording and detection of the dual beam interference signal verify the wave property of light. The presented setup employs fiber optical light path, enabling the setup to be resistant to external interference, easy to assemble and move, and low in cost. The presented experimental practice can give students more opportunities to broaden and deepen their understanding of the taught subject content, while using modern experimental instruments and working on problems. During the class, students can know how to use optical instruments in a proper way, understand light wave–particle duality and related concepts, and increase awareness and curiosity of related cutting-edge scientific research. According to the class questionnaire survey, students were satisfied with the practical experimental class. [ABSTRACT FROM AUTHOR]

Narinder Singh Kapany, considered by many as the father of fibre optics, was one of the first scientists to start the field of fibre-optics with ground-breaking demonstrations of optical fibre-based imaging, sensing, and optical communication systems. Although his seminal works in the area of fibre-optics are well-documented, much less is known about his equally important contributions in the development of biomedical optics. This article highlights Kapany's ground-breaking innovations in pushing the frontiers of biology and medicine by elaborating three selected examples from his work: (i) fibreoptics hypodermic probe for live-tissue imaging, (ii) photocoagulation of retina, and (iii) optical oximetry of blood. We discuss the basics of these ideas and focus on how Kapany overcame many challenges to demonstrate ready-to-use prototypes from scratch. These innovations form precursors to many modern-day instruments, which are essential for current medical applications. Kapany's life journey is yet another embodiment of how curiosity-driven research can change the course of human history. [ABSTRACT FROM AUTHOR]

Modern FPGA accelerators can be equipped with many high-bandwidth network I/Os, e.g., 64 x 50 Gbps, enabled by onboard optics or co-packaged optics. Some dozens of tightly coupled FPGA accelerators form an emerging computing platform for distributed data processing. However, a conventional indirect packet network using Ethernet's Intellectual Properties imposes an unacceptably large amount of the logic for handling such high-bandwidth interconnects on an FPGA. Besides the indirect network, another approach builds a direct packet network. Existing direct inter-FPGA networks have a low-radix network topology, e.g., 2-D torus. However, the low-radix network has the disadvantage of a large diameter and large average shortest path length that increases the latency of collectives. To mitigate both problems, we propose a lightweight, fully connected inter-FPGA network called OPTWEB for efficient collectives. Since all end-to-end separate communication paths are statically established using onboard optics, raw block data can be transferred with simple link-level synchronization. Once each source FPGA assigns a communication stream to a path by its internal switch logic between memory-mapped and stream interfaces for remote direct memory access (RDMA), a one-hop transfer is provided. Since each FPGA performs input/output of the remote memory access between all FPGAs simultaneously, multiple RDMAs efficiently form collectives. The OPTWEB network provides 0.71-μsec start-up latency of collectives among multiple Intel Stratix 10 MX FPGA cards with onboard optics. The OPTWEB network consumes 31.4 and 57.7 percent of adaptive logic modules for aggregate 400-Gbps and 800-Gbps interconnects on a custom Stratix 10 MX 2100 FPGA, respectively. The OPTWEB network reduces by 40 percent the cost compared to a conventional packet network. [ABSTRACT FROM AUTHOR]

Trapped atomic ensembles are convenient systems for quantum information storage in the long-lived sublevels of the electronic ground state and its conversion to propagating optical photons via stimulated Raman processes. Here we investigate a phase-matched emission of photons from a coherently prepared atomic ensemble. We consider an ensemble of cold atoms in an elongated harmonic trap with normal density distribution, and determine the parameters of paraxial optics to match the mode geometry of the emitted radiation and optimally collect it into an optical waveguide. [ABSTRACT FROM AUTHOR]

The use of advanced endoscopic airway equipment has become increasingly important to the provision of safe anaesthesia for patients with complex anatomical and pathological conditions. Fundamental to the correct selection and use of the equipment is an understanding of the physical properties underlying its construction and function. This relies primarily on conventional optics, fibreoptics, video sensors and light-emitting diode technology. [ABSTRACT FROM AUTHOR]

Rapid optical interrogation of flowing cells or particles is a powerful tool in the field of biomedical diagnostics. Determination of size and composition of fast-flowing cells, with diameters in the range of 2– 15 μ m , often require complex open-space optics and expensive high-speed cameras. In this work, a method to overcome these challenges by using a hydrodynamic flow-based microfluidic platform coupled with on-chip integrated fiber optics is reported. The lab-scale portable device developed uses a combination of on-chip lensed and non-lensed optical fibers for precision illumination. The narrow light beam produced by the lensed fiber (f = 150 μ m) enables precise optical analysis with high sensitivity. A planar arrangement of optical fibers at various angles facilitates multi-parametric analysis from a single point of interrogation. As proof of concept, the laboratory-scale portable bench-top prototype is used to measure fluorescence signals from CD4 immunostained cells and human blood samples. The performance of microfluidic flow analyzer is also compared to the conventional Guava® easyCyte 8HT flow cytometer. [ABSTRACT FROM AUTHOR]

The organization of nanoparticles in constrained geometries has attracted increasing attention due to their promising structures and topologies. However, the control of hierarchical structures with tailored periodicity at different length scales and topology stabilization in a dynamic environment are very limited and challenging. Herein, through self‐assembly of cellulose nanocrystals (CNCs) within an in situ formed hydrogel sheath using a simple microfluidic strategy, a new breed of liquid crystal (LC) fibers with hierarchical core–sheath architectures, metaperiodic cholesteric alignments, and 3D topological defects, termed as liquid metacrystal (LMC) fibers, is created. The resulting LMC fibers not only exhibit vivid, tunable interference colors, and even inverse optical activity but also have a unique ability to precisely regulate linearly and circularly polarized light in a half‐sync/half‐async form. Furthermore, robust hydrogel sheath enables the LMCs with alignment stability and configuration programmability during drying, which endows the unprecedented freedom to tailor different optical appearances for polarization‐based encryption and recognition. This work opens an avenue toward the fabrication of length‐scale colloidal LCs with continuous and stable topologies and expands the application regimes of LC materials in chiral optics and smart textiles. [ABSTRACT FROM AUTHOR]

Using an ultrafast photonic first‐order differentiator applied on a partially coherent field, the generation of two correlated temporal waveforms is reported and their correlation properties upon linear and nonlinear propagation along the two orthogonal polarization axes of a dispersive optical fiber are studied. Temporal correlations are maintained in linear propagation whereas Kerr nonlinearity generates anticorrelated temporal intensity patterns for both partially and uncorrelated fields. Experiments are in close agreement with the theoretical analysis. [ABSTRACT FROM AUTHOR]

Solitons have been the focus of intense research since their discovery in the nineteenth century and have revolutionized various fields of science and technology, leading to groundbreaking advancements in nonlinear dynamics, optics, communications, and other disciplines. As we are commemorating the 50th anniversary of the discovery of optical solitons, this article aims to provide the contributions of the scientific community in India towards advancement in this domain, shedding light on the fundamental properties, and applications of solitons through diverse theoretical models and analytical approaches in different physical systems, such as in optical fibers, Bose–Einstein condensates, plasma etc. This article is a tribute to the late Prof. Porsezian, a pioneering figure in the world of 'Optical Soliton'. This article is a compendium of notable scientific contributions from the Indian community to the field of Soliton Physics. ▪ • It's a tribute to the late Prof. Porsezian for his contribution to soliton research. • It intends to showcase Indian community's major contributions in soliton research. • Breakthroughs and notable works across the globe, mainly from India was highlighted. • Various solitons, from fibers to diverse media, were discussed in this article. [ABSTRACT FROM AUTHOR]

Optical coherence tomography (OCT) is a micron scale high-resolution optical technology that can provide real-time in vivo images noninvasively. The ability to detect airway mucosal and submucosal injury rapidly will be valuable for a range of pulmonary applications including assessment of acute inhalation smoke and burn injury. OCT has the potential ability to monitor the progression of airway injury changes including edema, hyperemia, and swelling, which are critical clinical components of smoke-inhalation injury. New Zealand white male rabbits exposed to cold smoke from standardized unbleached burned cotton administered during ventilation were monitored for 6 h using a 1.8-mm diameter flexible fiberoptic longitudinal probe that was inserted through the endotracheal tube. The thickness of the epithelial, mucosal, and submucosal layers of the rabbit trachea to the tracheal cartilage was measured using a prototype superluminescent diode OCT system we constructed. OCT was able to detect significant smoke-injury-induced increases in the thickness of the tracheal walls of the rabbit beginning very shortly after smoke administration. Airway wall thickness increased to an average of 120% (+/-33%) of baseline values by 5 h following exposure. OCT is capable of providing real-time, noninvasive images of airway injury changes following smoke exposure. These studies suggest that OCT may have the ability to provide information on potential early indicators of impending smoke-inhalation-induced airway compromise.

The development of telecommunications networks is currently dominated by fiber optics. The fiber optic has become a waveguide medium transmitting information with high frequency bands, high capacity and high speed. An optical amplifier is required to maintain electromagnetic signals when they propagate in far distance. One of the amplifiers, Fiber Raman Amplifiers (FRA) which is the light scattering from the light that comes with the phonon in the lattice of amplification medium produces photons that are coherent with the incoming photons. Many amplifiers are commonly used but the problems not only come from the amplifier but also the component circuit and system. By simulation method, FRA circuit is designed and operated in the form of pre-amplifiers to maintain a better signal from material interference and geometry. The simulation results show that the lowest BER value and the highest Q-factor are found at a distance of 10 km depicted by eye diagram. [ABSTRACT FROM AUTHOR]

In this paper, we demonstrate a widely tunable dual-wavelength fiber laser, which is based on a thulium-doped fiber and volume Bragg gratings triggering the emission wavelengths in the 2-μm band. A continuously tunable wavelength separation range (Δλ), from 1 to 144 nm (0.08–11.47 THz) is demonstrated, with > 4.5 W of output power over the tuning range. The laser emission exhibits a linewidth (FWHM) lower than 0.1 nm independent from wavelengths and Δλ, with more than 45 dB of a signal-to-noise contrast. A maximum output power of 7 W is obtained for shorter Δλ (1–14 nm), corresponding to a slope efficiency of 33% with respect to the incident pump power at 790 nm. [ABSTRACT FROM AUTHOR]

Traditional pyramidotomy models have a high mortality rate from breathing difficulties and show early recovery from the induced motor deficits. This study establishes a novel pyramidotomy technique in Sprague Dawley rats that generates persistent motor deficits and has a reduced mortality rate. We used viral neural tracing to identify the course and relative distribution of forelimb and hindlimb motor fibers (n = 9). On basis of the neural tracing data, the medullary pyramid was targeted dorsally from the cerebellar cortex for photothrombotic infarct lesioning (n = 18). The photothrombotic technique selectively destroyed the corticospinal fibers in the medullary pyramid with relative preservation of neighboring grey-matter tissue. MicroPET imaging using 2-deoxy-2-[18F]-fluoro-D-glucose (FDG-microPET) showed a decrease in regional cerebral glucose metabolism (rCGM) in the bilateral pyramid and ipsilateral sensory cortex (p < 0.001, FDR q < 0.05). In addition, the trapezoid bodies and superior olivary nuclei showed a decrease in rCGM, compatible with damage caused during the introduction of the optical fiber. Connected structures such as the inferior colliculi and auditory cortices also showed decreases in rCGM in both hemispheres (p < 0.001, FDR q < 0.05). There was a significant and persistent decrease in motor and sensory function in the contralateral limb following pyramidotomy, as demonstrated by performance in the single pellet reaching task and the foot-fault test. There was no operative mortality or loss of respiratory function in this study. These results indicate that photothrombotic pyramidotomy with a dorsal transcortical approach is a safe and reliable technique for generating a pyramidotomy model with persistent motor deficits. [ABSTRACT FROM AUTHOR]

A fiber optic distributed thermal response test (DTRT) conducted in well-documented heterogeneous geology is combined with laboratory thermophysical measurements of cores and novel data analysis techniques to provide a detailed description of variability in subsurface heat transfer. The results of this study show that appreciable variation in subsurface heat flow exists and can be quantified in a lithological context, which may aid in the optimization of future geothermal borefield design. District-scale borefields that are expected to contend with imbalanced loads and potential overheating may find additional value from knowledge of which geologic units to utilize and which to avoid. [ABSTRACT FROM AUTHOR]

Single-fiber laser treatment of the prostate has been widely accepted in the clinic due to its minimal invasiveness and high controllability. However, for large tumors, multiple insertions of the laser probe would be needed to achieve full coverage of the tumor, increasing the complexity of the treatment and occasionally resulting in the incomplete killing of tumor cells due to a mismatch between the planned insertion location and the actual probe insertion location. Treatment with a dual-fiber laser results in greater lesion coverage following a single insertion of the probe, with the lesion coverage being even greater than the sum of the coverage of two sequential insertion of a single-fiber laser probe, potentially reducing treatment time and clinical complications. Both theoretical and experimental analyses have been performed to evaluate the proposed dual-fiber laser treatment. A finite element model was established to simulate the treatment process. The simulation results indicated that there is a clear difference between the ablation coverage created using dual-fiber laser ablation and that created using the superposition of sequential single-fiber laser ablation. In addition, the coverage is dependent on the spacing distance between the two fibers. Both ex vivo and in vivo canine prostate tissues were treated by dual-fiber laser ablation, with lesions analyzed by magnetic resonance imaging (MRI), ultrasound imaging, and pathology. The results demonstrate that dual-fiber laser ablation can markedly increase the range of the ablation zone when compared with single-fiber modes. The safety and feasibility of dual-fiber laser treatment has been confirmed, and a treatment plan using dual-fiber laser ablation has also been proposed. [ABSTRACT FROM AUTHOR]

Drug-resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) are a target for new antimicrobial technologies. Far-UVC technology is an emerging disinfection method that directly kills microorganisms using light. In contrast with conventional UV sterilization, far-UVC light has antimicrobial capabilities without apparent harm to mammalian cells. This study examines the application of 224 nm far-UVC light delivered from a laser using an optical diffuser towards the goal of protecting against bacterial invasion around skin penetrating devices. Delivery of far-UVC using a laser and optical fibers enables exposure to unique geometries that would otherwise be shielded when using a lamp. Testing of the bactericidal potential of diffusing the far-UVC laser output over a large area was tested and yielded qualitative area killing results. The killing of MRSA using this method was also examined using an in vitro survival assay. Results followed a classic log-linear disinfection model with a rate constant of k = 0.51 cm2/mJ, which corresponds to an inactivation cross section of D90 = 4.5 mJ/cm2. This study establishes far-UVC delivered from a laser through an optical diffuser as a viable solution for disinfection of susceptible regions such as around catheters, drivelines, or other skin penetrating medical devices. [ABSTRACT FROM AUTHOR]

A further output power scaling of Yb-doped double-cladding photonic crystal fiber lasers, required for practical applications in many industrial fields, is currently prevented by thermal effects, which significantly worsen the beam quality. In this work the mode interaction and, consequently, the single-mode regime of Yb-doped air-silica symmetry-free photonic crystal fibers have been numerically investigated in different heat load conditions using simulation tools based on the finite element method. The effect of the main inner cladding geometric parameters, in particular of the inner cladding dimension, on the guided-mode delocalization has been analyzed, with the aim to identify a design of the large mode area active fiber providing single-mode operation despite the presence of thermal effects. Simulation results have demonstrated that the inner cladding enlargement causes a stronger coupling between core-guided and cladding modes, as well as an increase of the differential overlap between fundamental and first higher-order mode for moderate heat load values. However, the inner cladding influence becomes less important under severe heat load, being the fiber behaviour mainly affected by the thermally-induced refractive index change in the doped core. [ABSTRACT FROM AUTHOR]