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Bound states in the continuum (BICs) are widely exploited in all‐dielectric metasurfaces to significantly enhance the Q‐factor and second harmonic generation (SHG). However, a higher SHG conversion efficiency is overshadowed by the narrow transparency window of all‐dielectric materials and strict requirement of polarization‐matching. Herein, an augmented SHG assisted is demonstrated by symmetry‐protected quasi‐BICs from z‐cut wurtzite GaN metasurfaces, whose wide transparent range suppresses self‐absorption of second harmonic. Strong resonances emerge under both X‐ and Y‐polarized excitations, where the multipole characters of each eigenmode are quantitatively identified via decomposition simulations. The local field enhancement enabled by the extreme energy confinement of quasi‐BICs contributes to an efficient SHG, recording a conversion efficiency up to 2 × 10−7 at moderately low input peak intensity (≈1 GW cm−2), orders of magnitude larger than bulk GaN. With proper design, the overlapping X‐ and Y‐polarized resonances can support SHG from excitation with arbitrary polarizations. The alleviation of polarization‐matching remarkably enhances the SHG power by 66.2% under unpolarized illumination condition. The results of intense SHG reveal GaN as a promising candidate for high‐performance nanoscale nonlinear photonic devices. The weak polarization sensitivity of the designed structure will chart a novel course for the advancement of next‐generation efficient all‐dielectric metasurfaces. [ABSTRACT FROM AUTHOR]

In this paper, a temperature insensitive wide-dynamic-range distributed strain sensor with centimeter-level spatial resolution based on optical frequency domain reflection technology is proposed. It adopts a polarization-maintaining photonic crystal fiber as the sensing fiber, and experimental results demonstrate that its temperature sensitivity is much smaller than that of the standard polarization-maintaining fiber. Benefited from the specially designed cross-correlation algorithm, the sensor achieves the maximum measurable strain reaches 7000 μϵ with spatial resolution of 1.66 cm. This provides a new approach to address current issues with special fiber sensors, such as single-point sensing and low spatial resolution, which shows great significance for structural health monitoring of buildings, bridges and tunnels with urgent requirement of large dynamic range. [ABSTRACT FROM AUTHOR]

A double U-shaped PCF-SPR sensor is proposed for the detection of analytes with low refractive indexes (RI). The U-shaped structure facilitates the penetration of analytes. Compared with a single formant sensor, the sensor exhibits double formant characteristics. Therefore, the analytes to be measured can be identified more accurately. This study employs the finite element method (FEM) to analyze the sensor. The findings suggest that the sensor is capable of detecting analytes with low RI ranging from 1.15 to 1.33 over an ultra-wide wavelength range of 800–6400nm. The maximum wavelength sensitivities of the first and second peaks of the sensor are 54,300nm/RIU and 60,000nm/RIU, respectively. In addition, this paper introduces double peak shift sensitivity (DPSS), the highest DPSS value is 55,700nm/RIU. Owing to these distinct characteristics, the sensor has great application prospects in the field of biosensing, especially in drug detection. [ABSTRACT FROM AUTHOR]

Terahertz (THz) fields are increasingly being used to address the critical challenges associated with achieving high data rates and rapid communication. In this study, a hybrid plasmonic THz waveguide is designed and analysed operating in the 2.5–3.5 THz frequency range. The waveguide is constructed using gallium arsenide as the high-refractive-index core, surrounded by aluminium arsenide and silver placed on a high-density polyethylene (HDPE) substrate. Graphene is strategically positioned between the HDPE layers to enhance light confinement. The mode properties of the proposed waveguide are simulated with Comol Multiphysics using the finite-element method and show unique characteristics. Observation of the simulated results at 2.5–3.5 THz reveals a high effective refractive index of 3.79, a maximum effective mode area of 1.88 mm2, a high birefringence of 0.2, a low dispersion of 0.10 ps THz−1 cm−1, a high mode field diameter of 15.8 mm, a high beat length of 123 mm and a low confinement loss of 1.79 × 10−9 mm−1. These features make the proposed waveguide suitable for applications in photonic integrated circuits for THz communications. [ABSTRACT FROM AUTHOR]

An innovative photonic crystal fiber (PCF) biosensor using surface plasmon resonance (SPR) to diagnose six distinct kinds of cancers (skin cancer, cervical cancer, adrenal gland cancer, blood cancer, and breast cancer types 1 and 2) in cells is demonstrated here and incorporates with two microchannels and a bimetallic configuration. The numerical analysis utilizes the finite element method (FEM) combined with perfectly matched layers (PML). The plasmonic material employed in the biosensor is gold (Au), and a supportive material, titanium dioxide (TiO2), is combined with Au. By combining these two materials, the sensor's performance is improved. The numerical calculations indicate that breast cancer type 2 has the highest wavelength sensitivity (24,285.71 nm/RIU) and amplitude sensitivity (3959 RIU−1). The rest of the cancer cells' wavelength sensitivities are 11,000.00 nm/RIU (skin cancer), 13,333.33 nm/RIU (cervical cancer), 15,000.00 nm/RIU (blood cancer), 17,142.85 nm/RIU (adrenal gland cancer), and 21,428.57 nm/RIU (breast cancer type 1). This advanced biosensor has several uses in biological sensing and medical technology, and it has the potential to revolutionize cancer identification and medical diagnosis. [ABSTRACT FROM AUTHOR]

In response to the immediate requirements of modern high-speed and high-capacity integrated optical circuit development, this study introduces a broadband all-fiber polarization beam splitter (PBS) based on silicon dual-core photonic crystal fiber (PCF) and gold layers. Simulation results demonstrate that silicon as the substrate material is conducive to extending the operating range to the mid-infrared band of 3.0 ~ 3.6 μm. The modulation effect of the gold ring layers on the left and right sides of central elliptical hole is very impressive, and when the cladding hole diameter d1 = 1.3 μm, gold-coated hole diameter d2 = 1.8 d1 = 2.34 μm, hole-to-hole pitch Λ = 2.0 μm, gold layer thickness t = 50 nm, long axis a = 2.08 μm, and short axis b = 1.43 μm, coupling length ratio (CLR) between x- and y-polarized super-mode exactly is equal to 2. According to performance investigation by finite element method (FEM), this PBS is well suited for splitting out x-polarized light in core A, which can possess a minimum size of 0.66 mm, a maximum extinction ratio (ER) of 78 dB at 3.3 μm, a broad operating bandwidth of 450 nm, and a low insertion loss (IL) of 0.15 dB at 3.3 μm simultaneously. The proposed PBS features both high integration and high performance, which will be applicable to all-optical networks in mid-infrared fields. [ABSTRACT FROM AUTHOR]

A surface plasmon resonance-based hollow core photonic crystal fiber (HC-SPR-PCF) is developed to detect gasoline adulteration with kerosene. The SPR-PCF sensor is fabricated via stack and draw, and atomic layer deposition (ALD). The performance of SPR-PCF sensors, such as sensitivity, loss, figure of merit (FoM), responsivity, and response time, are analysed experimentally in the wide refractive index (RI) range of 1.428–1.45. This experimental result shows that the proposed sensor with thin gold and aluminium oxide (Au + Al 2 O 3 ) plasmon active material exhibits a high amplitude sensitivity (321.59/RIU), low loss (0.0529 dB/cm), high responsivity (0.355875), and good FoM (1247.5/RIU). The presented experimental study has excellent potential in biochemical sensing applications due to its high sensitivity, low loss, linearity and fast response time. [ABSTRACT FROM AUTHOR]

The exact soliton solutions of perturbed Gerdjikov-Ivanov equation with both constant and variable coefficients are constructed in this work through the application of the modified F-expansion method. This method is used for the very first time on the considered equation. As a result, the traveling wave solutions including soliton solutions are obtained. These soliton solutions enhance understanding of nonlinear phenomena in the fields of photonic crystal fibers, fiber optics and nonlinear fiber optics. The explanation of the obtained results is provided by drawing some 2-dimensional and 3-dimensional graphs using Mathematica. Furthermore, this study discusses the modulation instability for the considered model. The considered method is found to be effective, simple and useful to study the perturbed Gerdjikov-Ivanov equation. [ABSTRACT FROM AUTHOR]

Diabetes is a metabolic disease that seriously endangers human health, and monitoring glucose levels is one of the main diagnostic methods for its prevention and treatment. In this paper, we propose a high-performance glucose sensor based on the Sagnac interferometer (SI) utilizing photonic crystal fiber (PCF) with micro-holes. By setting two columns of micro-holes in the center of the PCF, the high birefringence effect is obtained to improve the detection sensitivity. All air holes are assumed to fill with the glucose solution, and the sensing characteristics of the PCF sensor are theoretically studied by the finite element method (FEM). The results show that the sensitivity and resolution of the PCF glucose sensor can reach 4.14 nm/(g/L) and 0.48 mg/dL within the concentration range of 0–120 g/L, respectively. In addition, the effects of the partial-filling methods and PCF structural parameters on the sensing performance are also analyzed to achieve optimal performance. The proposed glucose sensor possesses high sensitivity and simple structure, which exhibits good application prospects in the field of medical monitoring. [ABSTRACT FROM AUTHOR]

We have developed a new type of hybrid-structured Photonic Crystal Fiber (H-PCF) that includes a sectored core-cladding configuration. It's composed of a cladding with a regular circular sectored lattice structure and a core with a hexagonal sectored lattice structure. To extensively design, analyze, and calculate the fiber's properties, the finite element method has been used. The results provide validation for the superior performance of this novel fiber design. It simultaneously achieves extremely low effective material loss and confinement loss equal to 0.0145 cm⁻1 and 1 × 10⁻14 cm⁻1, respectively, at the 1 THz frequency. Furthermore, the fiber demonstrates nearly zero flattened dispersion (− 0.45 ± 0.55 ps/THz/cm) across the 0.9–1.3 THz frequency range, along with important attributes such as a large core power fraction (50%) and an effective area of 5 × 105 µm2. The suggested PCF design is practical for manufacturing utilizing currently available technologies. Moreover, the proposed PCF design, employing common structured regions in the circular and hexagonal patterns for the sectored cladding and core regions, respectively, is feasible for fabrication using existing technologies. Overall, this H-PCF shows significant potential for various THz applications, especially in THz wave guidance. [ABSTRACT FROM AUTHOR]

This study proposed photonic crystal fiber sensors with two distinct plasmonic layers were proposed and compared in order to identify skin cancer cells in comparison to normal blood cells. In order to attain high sensitivity for the detection of this surface plasmon resonance (SPR)-based sensor, a comparison is made between several layers of Silver-Titanium dioxide and Gold-Titanium dioxide. In addition, the presence of a TiO2 layer helps to lessen the chemical instability of silver and improves the SPR effect. For the purpose of this work, a numerical analysis of the sensor was performed using the finite element technique. It is possible to quantify the confinement loss of two sensors, as well as their sensitivity to changes in amplitude and wavelength, by modifying some influential factors such as the diameter of the airhole and the thickness of the plasmonic layer (Ag, Au). This allows for the evaluation of the effectiveness of the sensors in detecting a target analyte. For the purpose of identifying skin cancer cells, the highest amplitude sensitivity of silver as a plasmonic layer is 610 RIU-1, and the maximum spectral sensitivity is 7500 nm/RIU. The greatest spectral sensitivity of gold as a plasmonic layer for the detection of skin cancer cells is 7000 nm/RIU, while the maximum amplitude sensitivity of gold is 800 RIU-1. In-depth discussion has been held regarding the manufacturing procedure for the sensor that has been proposed. When it comes to the detection of organic and biological compounds, this biosensor that is now under investigation demonstrates promising characteristics due to its stability and good sensitivity. [ABSTRACT FROM AUTHOR]

We present the analytic form of the principal Hugoniot at all pressures. It is constructed by interpolating smoothly between three pressure (P) regimes. Specifically, (i) the low- P regime in which the Hugoniot is described by U s = C + B U p + A U p 2 , where U p and U s are particle and shock velocities, respectively, the values of C and B come from the experiment, and a small non-linearity (A ∼ 10 − 2 s/km) is added to the otherwise common linear form U s = C + B U p to match the next regime; (ii) the intermediate- P regime where the Hugoniot is described by the quantum-statistical model of Kalitkin and Kuzmina, U s = c + b U p + a U p 2 , with the values of c , b , and a determined virtually for all Z s (Z being the atomic number); and (iii) the high- P regime in which the Hugoniot is described by the Debye–Hückel model developed by Johnson. We determine the analytic form of the Hugoniot in the high- P regime and match it with those in the other two regimes. We show that no additional free parameter is required for the construction of the Hugoniot at all P except the six mentioned above: C , B , c , b , a , and Z. Comparison of the new model to experimental and/or theoretical data on aluminum, iron, silicon, and lithium fluoride, the four materials for which such data exist to very high P , demonstrates excellent agreement. Our approach applies to both elemental substances and complex materials (compounds and alloys) and can be used to predict the analytic forms of the yet unknown Hugoniots as well as to validate experimental results and theoretical calculations. The new model can be adopted for the description of the principal Hugoniots of porous substances and can be generalized for radiation-dominated (strong) shocks. [ABSTRACT FROM AUTHOR]

This review paper comprehensively analyzes recent advancements in optical fiber‐based biosensors, focusing on conventional fiber and photonic crystal structures. This paper overviews the significant applications of optical fiber biosensors, including bioimaging, quality analysis, food safety, and field environment monitoring, setting the stage for subsequent discussions. The primary objective of the review is to systematically evaluate recent literature concerning optical fiber‐based biosensors, emphasizing their sensitivities and resolutions. The second section explores integrating plasmonic materials such as graphene, TDMC, germanium, black phosphorus, and silicon within optical fiber biosensors, elucidating their roles in enhancing sensitivity and resolution in biosensing applications. A detailed examination of photonic crystal fibers (PCF) follows, categorizing them into internally and externally metal film‐coated biosensors, highlighting their distinct advantages and limitations. Comparative analyses in two tables delineate the performance and sensitivity of optical fiber‐based biosensors, mainly focusing on different coating strategies. The final section of the review discusses emerging trends and applications in optical fiber biosensing technologies, underscoring their potential to transform biomedical and environmental monitoring fields. By synthesizing recent developments and challenges, this review aims to offer researchers and practitioners a comprehensive understanding of optical fiber‐based biosensors, facilitating informed decision‐making and driving further advancements in the field. [ABSTRACT FROM AUTHOR]

A light beam carrying orbital angular momentum (OAM) is characterized by a helical phase‐front that winds around the center of the beam. These beams have unique properties that have found numerous applications. In the field of data transmission, they represent a degree of freedom that could potentially increase capacity. While an efficient method for (de)composing beams based on their OAM exists for free‐space optics, a device capable of performing this (de)composition in an integrated, compact fiber application without the use of external active optical elements and for multiple OAM modes and multiple wavelengths simultaneously has not been reported. In this study, two mechanisms are combined in a waveguide structure to demonstrate as a proof of principle that this can serve as a broadband fiber OAM (de)multiplexer. The structure design is based on the adiabatic principle used in photonic lanterns for highly efficient conversion of spatially separated single modes into eigenmodes of a few‐mode fiber. In addition, an artificial magnetic field is introduced by twisting the structure, which removes the degeneracy between modes having the same absolute OAM. This structure could simplify, stabilize, and miniaturize the creation or decomposition of OAM beams, making them useful for various applications. [ABSTRACT FROM AUTHOR]

This study presents the design and analysis of a novel surface plasmon resonance sensor based on D-type photonic crystal fiber. The analyte channel in the sensor comprises an open ring with a thin gold film deposited on the channel, inducing the surface plasmon resonance effect to enhance the resonance effect and improve the spectral sensitivity of the sensor. The proposed design eliminates the need to introduce liquid into the analyte channel. Upon inserting the sensor into the vessel, the analyte automatically flows into the liquid channel. Simulations illustrate the capability of the proposed sensor to detect low refractive indices spanning from 1. 1 5 to 1. 2 6 , exhibiting a remarkable spectral sensitivity of up to 9000 nm/RIU. The surface plasmon resonance sensor presented in this study emerges as a competitive candidate for applications requiring low refractive index detection. It is all because of its promising sensing results, wide refractive index sensing range, and simple, compact fiber design. [ABSTRACT FROM AUTHOR]

A circular defect in 2D photonic crystal (CirD) lasers is developed, which has the potential to achieve a target communication density of 10 Pbps cm−2 for intrachip optical communications by vertical current injection. The AlGaOx cladding layer's oxidation width strongly influences the device's light confinement and electronic resistance. Herein, samples with different oxidation widths are fabricated and the relationship between threshold power and oxidation width through photoexcitation is revealed. The optimal range of the oxidation width is found to be 349–439 nm, which can ensure low electronic resistance and low threshold power. [ABSTRACT FROM AUTHOR]

The use of photonic crystal (PhC) to form photonic bandgaps is expected to be applied to optical communications, and various studies have been conducted on this technology. In a previous study, the current‐injected Circular Defect (CirD) in 2D PhC laser is proposed. At that time, the dry‐etching process involves three steps. However, three‐step dry etching cannot be used to simultaneously form drainage trench and PhC air holes. In this study, a one‐step dry‐etching process for CirD lasers is conducted. Optical measurements are performed on the successfully fabricated samples. As a result, the first lasing of a CirD laser with a contact layer and an upper cladding layer fabricated with a one‐step dry etching is confirmed. [ABSTRACT FROM AUTHOR]

In this paper, a novel D-shaped photonic crystal fiber (PCF) refractive index (RI) sensor based on surface plasmon resonance (SPR) effect is proposed. By introducing a smiley-faced hole and Ag-TiO2 composite micro-grating, the high RI sensing performances can be realized. With finite element method, the propagation characteristics of the proposed D-shaped SPR-PCF RI sensor are numerically investigated. The simulation results show that the average wavelength sensitivity (WS) is 5400 nm/RIU, and the maximum WS can reach 15,500 nm/RIU in the RI range from 1.30 to 1.39. Besides, the proposed D-shaped SPR-PCF RI sensor can obtain the maximum resolution (R) of 4.95 × 10−5RIU and the maximum figure of merit (FOM) of 423.78 RIU−1, respectively. It is believed that the proposed SPR-PCF RI sensor has potential applications in the fields of environmental monitoring, biomedical analysis, and food safety management. [ABSTRACT FROM AUTHOR]

A novel Segmented Clad-Graded Index (SC-GI) photonic crystal fiber with a circular core composed of As38Se62 is proposed to realize the supercontinuum spectrum in the entire transparency range of As38Se62 (2–10 μm). SC-GI PCF conveys dual Zero Dispersion Wavelengths at around 2.4 μm and 6.4 μm. The devised PCF also offers a very small effective mode area of 2.46 μm2 and a very high nonlinear coefficient of 12,005 W−1 km−1 at the pump wavelength of 2.4 μm. Detailed numerical simulations reveal that a short length of SC-GI PCF (~ 28 mm) is capable of showing a broad SC spectrum ranging from 3 to 9.5 μm (− 30 dB level of power) using an input source of moderate peak power (1.8 kW) pumping at 3.4 μm. To the best of the author's knowledge, this is the first time report of SCG in Segmented Cladding Fiber design. The evaluated SC covers the transparency window of the background material and also covers the mid-IR region. This type of high broadening opens the gateway for applications like optical metrology, optical coherence tomography (OCT), food quality control, telecommunications and future applications covering the Mid-IR region.Please confirm the corresponding author is correctly identified and amend if necessary.Yes, Corresponding author is correctly mentioned. [ABSTRACT FROM AUTHOR]

In this article, a surface plasmon resonance (SPR) sensor based on photonic crystal fiber (PCF) is simulated and analyzed by finite element method (FEM). Gold and titanium oxide (TiO2) are used as plasmonic layers. The TiO2 layer is placed under the gold layer to increase the sensitivity of this sensor. The sensor's top and bottom surfaces are polished, and the plasmonic layer is placed on both these surfaces. Unlike sensors with typical external circular coating, less plasmonic material is used. Additionally, unlike internal coating sensors, there is no issue of partial air holes coating and achieving a uniform thickness of the plasmonic layer. Also using two plasmonic levels can expand the range of refractive index (RI) detection. The sensor's structure creates birefringence, allowing complete coupling between the core mode and both plasmonic layers. This results in more reliable detection ability. By optimizing the dimensions and arrangement of air holes and the sensor's structure, the ability to detect unknown analytes in the ultra-wide range of refractive index of 1.21–1.41 with the maximum wavelength sensitivity (WS) of 61,000 nm / RIU , the maximum amplitude sensitivity (AS) of 1294.29 RIU - 1 , the maximum figure of merit (FOM) of 657.14 RIU - 1 and the sensor resolution (SR) of 4.35 × 10–6 RIU have been obtained. This sensor operates in the visible to near-infrared wavelength range. During its design, feasibility in construction was taken into consideration, along with reducing the complexity and multiplicity of structural parameters. As a result, the sensor delivers excellent performance in detection parameters and is a suitable option for RI detection applications like organic chemicals and biosensing. [ABSTRACT FROM AUTHOR]

A highly sensitive and simple structure side-polished micro-structured fiber (MOF) refractive index (RI) sensor based on surface plasmon resonance is proposed and studied by the finite element method. The gold nanofilm used to stimulate plasmons is directly deposited on the inner wall of the open-loop channel of a MOF consisting of an arrangement of six cladding air-holes. The sample analyte is arranged on the outer surface of the optical fiber to improve the utilization rate of the sensor and reduce the tediousness of operation. Meanwhile, in order to increase the leakage intensity of evanescent field, three large air-holes were introduced near the fiber core. Research has shown that the proposed sensor can achieve sensing detection in the range of 1.19–1.37 RI. The maximum sensitivity in the x-polarized direction can reach 12,500 nm/RIU, and its corresponding resolution is 3.64 × 10–5 RIU. Moreover, it has a high linear response of 0.9944 within the RI detection range of 1.19–1.33. Obviously, the proposed sensor has a simple structure, wide RI detection range, and high sensitivity, which can make it widely used in biomedical and analytical chemistry. [ABSTRACT FROM AUTHOR]

A hollow-core photonic crystal fiber based Refractive Index sensor in the terahertz frequency regime for bio-sensing application is proposed in this paper. Refractive index variation is used for the identification of different analytes with refractive indices ranging from n = 1.35 to 1.39. Zeonex is chosen as the fiber material. The proposed photonic crystal fiber (PCF) sensor features a solitary rectangular core enclosed by an arrangement of 16 rectangular air holes within the cladding area with different heights and widths. Simulation and numerical analysis are conducted using Finite Element Method-based based Comsol Multiphysics Software. The proposed PCF sensor exhibits relative sensitivity of 98.8%, an Effective Mode Area of 1.06 × 10−7 m2 with a very low confinement loss of 7.751 × 10–14 dB/cm are achieved at a frequency of 1.4 THz for an analyte of refractive index 1.39 in X Polarization direction of electric field. Moreover, birefringence, non-linearity, effective refractive index and power fraction are also analyzed. Further simple PCF structure based on rectangle ensures that fabrication is feasible with current fabrication techniques.Please check and confirm that the authors and their respective affiliations have been correctly identified and amend if necessary.I have checked the authors name and affiliations and found its correct.Kindly check and confirm whether the corresponding author and corresponding mail ID is correctly identified.I have checked about corresponding authors name and email id. I found it correct. [ABSTRACT FROM AUTHOR]

This article proposes a novel Si3N4-based five-ring hexa-circular photonic crystal fiber (PCF) that shows a remarkably high nonlinear coefficient (NLC) and birefringence (Br). Several distinctive optical features, including birefringence, nonlinearity, effective area, numerical aperture, confinement loss, dispersion, etc., are investigated utilizing the COMSOL Software. The simulation analysis demonstrates that a zero-crossing dispersion for Y- polarization and an extremely high Br and NLC of 0.22 and 2687.51 W - 1 Km - 1 are reached at the wavelength of 1.55 μ m . The proposed PCF, having extremely high Br and NLC properties, can be useful for prospective future applications in the areas of supercontinuum generation, nonlinear optics, polarization-maintaining, and so on. [ABSTRACT FROM AUTHOR]

This paper presents a polarizing beam splitter (PBS) based on a hexagonal lattice silver-filled photonic crystal fiber (PCF) with two silver wires, which possesses advantages such as a short splitting length, high extinction ratio (ER), and an ultra-wide bandwidth in commonly used communication bands. Utilizing the full-vector finite element method (FV-FEM), thorough investigations were conducted on lasers within the wavelength range of 1.1 to 1.9 μm. The PBS demonstrates a working bandwidth of 725 nm (1.14 to 1.865 μm) under an ultra-short splitting length of 55.3 μm, with an ER exceeding 20 dB, covering all bands of O + E + S + C + L + U optical communication, and achieving a maximum ER of 74.65 dB, where the surface plasmon resonance (SPR) effect of silver metal plays a significant role. It not only features an ultra-short splitting length and an ultra-wide splitting bandwidth but also exhibits excellent manufacturing tolerances and anti-interference capabilities. This polarizing beam splitter represents a promising candidate in communication and may find various applications in optical communication. [ABSTRACT FROM AUTHOR]

Manipulating the propagation of mid-infrared (mid-IR) light is crucial for optical imaging, biosensing, photocatalysis, and guiding photonic circuits. Artificially engineered metamaterials were introduced to comprehensively control optical waves. However, fabrication challenges and optical losses have impeded the progress. Fortunately, two-dimensional van der Waals (vdW) materials are alternatives because of their inherent optical properties, such as hyperbolic behavior, high confinement, low loss, and atomic-scale thickness. In this research, we conducted theoretical and numerical investigations on the α-phase molybdenum trioxide, a biaxial vdW material, with patterned graphene to assess the potential of the tunable focusing of mid-IR light. Our proposed method directly alters the path of excited light to focus mid-IR light by negative refraction. Further, the patterned graphene in our design offers enhanced focusing characteristics, featuring a significantly reduced waist diameter with 1/92 of the free-space wavelength, an enhanced beam quality without pronounced field ripples, and a fivefold increase in field intensity. Moreover, our approach significantly preserves the waist diameter of the focused beam while facilitating directional steering. Thus, the focused beam can propagate in a canalized manner toward the desired direction. These advancements lay the foundation for promising applications in planar photonics. [ABSTRACT FROM AUTHOR]

This document is an editorial for a special issue of the journal Micromachines on photonic chips for optical communications. The editorial highlights the importance of integrated photonic chips in meeting the demands for cost-effectiveness and energy efficiency in applications such as data center interconnections and long-distance information transfer. The special issue features ten papers, six of which address challenges in the field of photonic chips, while the remaining four are review papers covering topics such as AlGaAs, femtosecond laser-fabricated chips, slow-light electro-optic modulators, and spectral interferometry with frequency combs. The editorial provides a brief overview of each review paper, discussing the materials, fabrication methods, and applications of integrated photonic chips. The document concludes by emphasizing the rapid evolution and practicality of photonic chips in optical communications. [Extracted from the article]

Organic single crystals with near‐infrared (NIR) emission demonstrate their excellent optical communications from well photonic confinement and low optical waveguide loss, which are considered as competitive candidates toward advanced optoelectronics. However, the increasingly diverse and sophisticated application demands result in the complicated design of NIR devices, which is hardly realized solely by the intrinsic properties of individual crystals. Herein, a programmable assembly strategy is presented to fabricate organic heterostructures. Triphenylene (TP), pyrene (Py) and 7,7,8,8‐tetracyanoquinodimethane (TCNQ) are primary selected to prepared organic cocrystals with narrow band gap and near‐infrared emission. Importantly, the charge‐transfer alloy with tunable emission from 700 nm to 850 nm and branched heterostructures with multichannel characteristics are prepared from these organic cocrystals by following the growth kinetics process at molecular level and lattice matching principle at structural level, respectively. Theses prepared heterostructures exhibit optical logic operation capabilities, which can serve as optical modulators. This work provides new insights into the manufacturing of organic NIR heterostructures applied in advanced optoelectronics. [ABSTRACT FROM AUTHOR]

The advent of nanotechnology has motivated a revolution in the development of miniaturized sensors. Such sensors can be used for radiation detection, temperature sensing, radio-frequency sensing, strain sensing, and more. At the nanoscale, integrating the materials of interest into sensing platforms can be a common issue. One promising platform is photonic crystal fibers, which can draw in optically sensitive nanoparticles or have its optical properties changed by specialized nanomaterials. However, testing these sensors at scale is limited by the the need for specialized equipment to integrate these photonic crystal fibers into optical fiber systems. Having a method to enable rapid prototyping of new nanoparticle-based sensors in photonic crystal fibers would open up the field to a wider range of laboratories that could not have initially studied these materials in such a way before. This manuscript discusses the improved processes for cleaving, drawing, and rapidly integrating nanoparticle-based photonic crystal fibers into optical system setups. The method proposed in this manuscript achieved the following innovations: cleaving at a quality needed for nanoparticle integration could be done more reliably (≈100% acceptable cleaving yield versus ≈50% conventionally), nanoparticles could be drawn at scale through photonic crystal fibers in a safe manner (a method to draw multiple photonic crystal fibers at scale versus one fiber at a time), and the new photonic crystal fiber mount was able to be finely adjusted when increasing the optical coupling before inserting it into an optical system (before, expensive fusion splicing was the only other method). [ABSTRACT FROM AUTHOR]

A new type of anti-resonant hollow-core fiber for terahertz waveguides is proposed. By introducing central support pillars and an elliptical structure, the fiber achieves high birefringence while maintaining low confinement loss and low material absorption loss. The fiber structure is optimized through simulation using the finite element method. The optimized fiber exhibits a birefringence of up to 1.22 × 10−2 at a frequency of 1 THz, with a confinement loss of 8.34 × 10−6 dB/cm and a material absorption loss of 7.17 × 10−3 dB/cm. Furthermore, when the bending radius of the fiber is greater than 12 cm, the bending loss of the anti-resonant optical fiber at 1 THz is less than 1.36 × 10−4 dB/cm, demonstrating good bending resistance and high practical value. It is expected to play a significant role in optical communication systems. [ABSTRACT FROM AUTHOR]

This paper presents a novel pentagonal structure dual-core photonic crystal fiber polarizing beam splitter (PS-DC-PCF PBS) filled with a nematic liquid crystal (NLC) in the central hole. Unlike previous designs with symmetric arrangements, the upper and lower halves of the structure have different air hole arrangements. The upper half consists of air holes arranged in a regular quadrilateral pattern, while the lower half features a regular hexagonal arrangement of air holes. By filling the central hole with birefringent liquid crystal, the birefringence of the structure is enhanced, reducing the coupling lengths along the x polarization and y polarization directions. The polarization properties, coupling characteristics, and the influence of different structural parameters on the extinction ratio of the polarizing beam splitter are analyzed using the full-vector finite element method. Simulation results demonstrate that the designed PS-DC-PCF PBS achieves a maximum extinction ratio (ER) of 72.94 dB with a splitting length of only 61.9 μm and a wide operating bandwidth of 423 nm (1.324–1.747 μm), covering most of the O, E, S, C, L, and U communication bands. It exhibits not only ultra-short splitting lengths and ultra-wide splitting bandwidth but also good manufacturing tolerances and anti-interference capabilities. The designed PS-DC-PCF PBS could provide crucial device support for future all-optical communication systems and has potential applications in fiber optic communication or fiber laser systems. [ABSTRACT FROM AUTHOR]

We present a compact laser system for quantitative two-photon excitation spectra measurements and ratiometric two-photon imaging of fluorescent protein indicators. The fundamental of the system is a short segment of photonic crystal fiber (PCF), which supports a nonlinear transformation of low-power ultrashort pulses by preserving temporal coherence, and this generates an ultrafast almost octave-spanning supercontinuum (SC). Accurate sculpting of the SC by its amplitude and phase modulation provides implementation of the spectroscopic and microscopic modalities. The spectroscopic one was exhibited by two-photon action cross section spectra measuring for the genetically encoded fluorescent sensing proteins of the vital biochemical parameters: acidity (SypHer3s), concentration of hydrogen peroxide (HyPer3 and HyPer7), redox status of NADH and glutathione (RexYFP and Grx1-roGFP2), hypohalous acids and their derivatives (Hypocrates). For the microscopy, we investigated and optimized the intensity pump pulse profiles under the high numerical objective by dispersion scan technique. We conducted real-time monitoring of the dynamics of hydrogen peroxide in HeLa cells with subcellular spatial resolution by means of ratiometric two-photon imaging of Hyper7 sensors. The presented hybrid laser system provides an ideal optical toolbox in order to develop ratiometric fluorescent sensors, which can be visualized in vivo using two-photon microscopy. [ABSTRACT FROM AUTHOR]

Polarization is a crucial characteristic of electromagnetic fields, and the ability to fully control it has many useful applications. While novel nanophotonic devices have been designed to achieve unprecedented capability to manipulate light on demand, their usage in the complete control of polarization states for the transmitted light has been relatively limited, and traditional design methods always produce devices with narrow operation bandwidths. In this work, a two‐phase topology optimization strategy is proposed in conjunction with adjoint method to inverse design photonic crystal slabs capable of complete polarization control. It successfully produces devices operating over a broad bandwidth that is significantly larger than the current state‐of‐the‐art designs, and their performances are also robust to material loss. This is also find that the C2v symmetry of the structure can regularize the problem, so that less simulation time and faster convergence can be obtained without compromising performance. This study demonstrates the power of the inverse design method, which can be further applied to achieve more complex polarization control and beyond. [ABSTRACT FROM AUTHOR]

In this article, band structure calculations of two dimensional (2D) anisotropic photonic-crystal fibers (PhCFs) are considered. In 2D PhCFs, Maxwell's equations for the transversal electric and magnetic mode become decoupled, but the difficulty, arising from the anisotropic permittivity ε and/or permeability μ , plaguing the frequency-domain finite difference method, especially the original Yee's scheme, is our top concern. To resolve this difficulty, we re-establish the connection between the lowest order finite element method with the quasi-periodic condition and Yee's scheme using 2D non-orthogonal mesh, whereby the decoupled Maxwell's equations in 2D anisotropic PhCFs are readily discretized into a generalized eigenvalue problem (GEP). Moreover, we spell out the nullspace of the resulting GEP, if it exists, and explicitly construct the Moore–Penrose pseudoinverse of the singular coefficient matrix, whose smallest positive eigenvalues can be solved by the inverse Lanczos method. Extensive band structures of 2D PhCFs are calculated and benchmarked against reliable results to demonstrate the accuracy and efficiency of our method. [ABSTRACT FROM AUTHOR]

Maintaining high fundamental mode purity in low‐loss single‐ring hollow‐core photonic crystal fiber remains a key challenge. Here a double‐clad anti‐resonant‐reflecting design is reported that, through modal filtering, provides high suppression of higher‐order modes while maintaining a low‐loss fundamental mode. The structure consists of a ring of six thin‐walled capillaries fused to the inner wall of a thicker‐walled capillary that is in turn fused at a single point to the silica outer cladding. Greater than 40 dB m−1 suppression of higher order modes over a 6 nm wide window whose central wavelength can be tuned by adjusting the gas pressure is observed. The novel design paves the way to practical applications of such fibers in high‐quality laser beam delivery and low‐noise optical‐signal transmission. [ABSTRACT FROM AUTHOR]

In this research, we proposed and numerically investigated a D-shaped dual-core photonic crystal fiber (PCF) refractive index (RI) sensor based on surface plasmon resonance (SPR), and a plasma material indium tin oxide (ITO) is deposited on the polished surface of a D-shaped PCF to produce the SPR effect. The proposed PCF sensor incorporates a dual-core structure and innovatively introduces an elliptical air hole, which increases the coupling of the SPR effect, resulting in a notable improvement in sensor performance. This enhancement enables the sensor to efficiently detect variations in the RI of the analyte. Utilizing the finite element method (FEM), we analyzed the influencing characteristics of sensor performance, meticulously investigating and optimizing various structural parameters. In the RI sensing range spanning from 1.18 to 1.33, the designed PCF sensor exhibits an outstanding maximum wavelength sensitivity of 29,300 nm/RIU, along with the highest achievable amplitude sensitivity of 261.01 RIU−1. Upon analyzing the light signal modulated by the sensor, the findings unequivocally demonstrate that the proposed sensor displays outstanding sensitivity to changes in the analyte's RI via the SPR effect. This responsiveness enables effective and precise real-time detection. The proposed sensor is characterized by exceptional sensing performance, strong economic feasibility, and low manufacturing intricacy. Consequently, the proposed sensor can be used to detect medical oxygen, anesthetics, methane gas, glucose, fluorine-containing organics, etc., and it holds a diverse array of promising applications spanning industrial detection, biochemical analysis, and medical diagnostics. [ABSTRACT FROM AUTHOR]

Surface plasmon resonance (SPR) technology–based biosensors, including photonic crystal fiber (PCF-SPR) biosensors, have been investigated for their potential in cancer detection. The biosensors can detect biomolecules in a label-free and real-time manner, which results in high sensitivity and specificity. This article provides a comprehensive analysis of the current and future trends in PCF-SPR biosensors for cancer detection. The study commences by presenting the fundamental principles of SPR and PCF-SPR biosensors, highlighting their comparative benefits over conventional biosensors. Recent studies utilizing PCF-SPR biosensors for cancer detection are reviewed, focusing on detecting cancer biomarkers and cancer cells in bodily fluids. The study examines the challenges and limitations of PCF-SPR biosensors in cancer detection, including the requirement for enhanced sensitivity and selectivity. Additionally, the review emphasizes the need for further research to address these limitations. Furthermore, the article explores potential avenues for advancing PCF-SPR biosensors in the realm of cancer detection. The research explores the utilization of novel sensing materials and their properties, different performance parameters. The findings of the review suggest that PCF-SPR biosensors hold great potential for detecting cancer and could be further developed and applied in clinical applications. [ABSTRACT FROM AUTHOR]

In this paper, we propose and numerically characterize the optical characteristics of a dual eccentric-core D-shaped photonic crystal fiber (PCF) surface plasmon resonance (SPR) refractive index (RI) sensor. The dual eccentric-core structure can leak more power to plasma film to excite SPR phenomenon than conventional structures. We investigate the influences induce by diameter of air holes, distance between air holes and thickness of gold film. The results show that our sensor has the wavelength sensitivities (WS) of 44,000 nm/RIU for odd mode and 39,000 nm/RIU for even mode. Moreover, the sensor has the detection range of RI from 1.00 to 1.37, the maximum figure-of-merit (FOM) of 325/RIU, maximum resolution of 2.27 × 10−6 RIU for analyte RI change of 0.1 nm, and the minimum full-width at half-maximum (FWHM) of 56 nm. The sensor has wide application prospects in methane, blood plasma, and methanol detecting. [ABSTRACT FROM AUTHOR]

This paper presents a dual-core two-parameter optical fiber sensor based on the surface plasmonic resonance (SPR) effect. It is analyzed by the finite element method. The proposed sensor is a dual-channel structure designed with photonic crystal fiber (PCF) as the base material: one channel is coated with a gold film to measure the refractive index (RI) of the solution to be measured, and the other channel is coated with a gold film and polydimethylsiloxane to measure the temperature of the solution to be measured. The exposed microslot structure on both sides reduces the complexity of sensing measurements. The results show that the maximum RI sensitivity of the sensor is 19,900 nm/RIU, and the maximum sensitivity to temperature is 8.7 nm/℃. This work is conducive to realizing a PCF sensor with high sensitivity, large measurement range, real-time monitoring, and easy preparation. As a result, the sensor is expected to be widely used in fields such as biology and chemicals. [ABSTRACT FROM AUTHOR]

An ultrahigh sensitivity surface plasmon resonance sensor based on double-side polished photonic crystal fiber is designed, and the gold film with a zigzag cross section is used as the plasmonic material. We study the refractive index sensing characteristics of the proposed sensor by numerical simulation. The results show that compared with the flat gold film structure, the zigzag gold film structure effectively improves the sensing performance, and the sensitivity and resolution of the sensor are significantly enhanced. The maximum wavelength sensitivity and resolution of the proposed sensor can reach 20,000 nm/RIU and 5.00 × 10−6 RIU, respectively. The working wavelength range of the sensor is between 590 and 1200 nm, and the refractive index range that can be used for detection is 1.350 RIU-1.400 RIU. This can be applied to precise detection of extracellular vesicles, breast cancer cell, and red blood cells. The proposed sensor has significant advantages such as stable structure, ultrahigh sensitivity, fast response, small size, and saving noble metal. It has great application potential in biomedical testing and medical equipment. [ABSTRACT FROM AUTHOR]

Terahertz (THz) spectroscopy has become a potent tool for label-free, non-destructive chemical sensing, with applications that range from security screening to pharmaceutical investigation. To expand the possibilities of THz spectroscopy, it is essential to improve its sensitivity and selectivity. In this study, we present a brand-new optical fiber design that is specifically suited to take use of surface-enhanced spectroscopic features in the terahertz range: an octagonal photonic crystal fiber (PCF) with a square core. According to this analysis, a five-layer construction with square air openings for the core and cladding and an octagonal shape would be best. The mathematical study is accomplished using the PML's boundary condition with a finite element method (FEM) at the propagation of THz waves. The developed octagonal PCF sensor accomplishes exceptionally high relative sensitivity (90.65%, 91.93%, 93.06%) at 1.3 THz for three compounds, including water (n = 1.330), ethanol (n = 1.354), and benzene (n = 1.366), following the simulation method. In contrast, for the same three compounds at 1.3 THz, the low confinement loss (CL)'s are 2.12 × 10−13 dB/m, 2.00 × 10−13 dB/m, and 1.88 × 10−13 dB/m, respectively. In addition, we investigated the possible uses of this unique fiber in numerous industries, such as chemical sensing, environmental monitoring, and biomedical diagnostics. In terms of terahertz chemical sensing, the octagonal PCF with square core opens up previously untapped possibilities for the creation of highly sensitive and selective THz spectroscopic devices with significant societal implications. [ABSTRACT FROM AUTHOR]

Due to the limitation of materials, PIC cannot achieve large magnitude phase modulation in a small size, and lacks the reconfigurable ability. Because of its birefringence characteristic, liquid crystal can be used in the liquid crystal on silicon (LCoS) device to achieve a large amount of phase modulation in a small size and has the capacity of reconstruction. Based on the experimental results of LCoS devices and basic liquid crystal waveguide devices, the liquid crystal waveguide device is prepared. While retaining the LCoS spatial optical phase modulation capability, the liquid crystal waveguide and phase modulation capability are realized. The beam splitter, optical switch, and Mach–Zehnder interferometer structure are constructed, which verifies the feasibility of the liquid crystal waveguide phase modulator. [ABSTRACT FROM AUTHOR]

In this paper, a surface plasmon resonance (SPR) sensor based on photonic crystal fiber (PCF) which can be filled with multiple analytes is proposed. The sensor has two elliptical groove microchannels. By changing the depth of the groove, the distance between the analyte to be measured and the sensor core can be reduced, thereby enhancing the energy coupling between the core mode and the plasma mode. The sensor can achieve both single-channel operation and dual-channel simultaneous measurement, which can effectively improve the detection efficiency. When the two channels work simultaneously, the maximum wavelength sensitivity of 1900 nm/RIU and 18,000 nm/RIU can be achieved by channel 1 and channel 2, respectively. The refractive index detection range of the sensor is 1.17 to 1.30. As far as we know, this is the first PCF-SPR sensor that dual channels are introduced into low refractive index detection. [ABSTRACT FROM AUTHOR]

This article presents a highly sensitive plasmonic sensor with a focus on enhancing its capabilities through innovative design and simple geometric structure. A hexagonal-shaped photonic crystal fiber (PCF) based surface plasmon resonance sensor is designed and proposed for external sensing applications. The plasmonic material is made of gold and positioned on the outer side of the designed PCF. For detection purposes, the flow of the testing analyte is introduced on the exterior section of the PCF. The sensing capability of this innovative sensor is meticulously examined using the finite element technique facilitated by the COMSOL Multiphysics software. The suggested sensor, with a refractive index of 1.38, has a maximum amplitude sensitivity and wavelength sensitivity of 765.86 RIU−1 and 8,000 nm/RIU respectively. At the same refractive index, the sensing resolution of the sensor is 1.31 × 10–5 for amplitude sensitivity and 1.25 × 10–5 for wavelength sensitivity. Additionally, the sensing capability of the sensor lies in the range of the analyte refractive indices from 1.33 to 1.39. Furthermore, the sensing performance of the designed sensor is analyzed by optimizing the values of several design parameters including air-hole diameter, pitch, and gold layer thickness. The suggested sensor can recognize biological analytes with high sensitivity, improved sensing resolution, and appropriate linearity. [ABSTRACT FROM AUTHOR]

We propose three hollow-core anti-resonant fibers with different nested tube structures and numerically analyse their confinement loss, single-mode performance and bending loss by using the finite element method. The results show that the nested semi-elliptical structure FD#2 and the hybrid nested FD#3 structure have excellent transmission performance. The confinement loss of FD#2 and FD#3 at 1.55 µm is 0.00037 dB/km and 0.0004 dB/km respectively, and the high order mode extinction ratio is around 1700 for both FD#2 and FD#3. The bandwidths of FD#2 and FD#3 with losses less than 0.01 dB/km are within 1.36–1.73 μm and 1.42–1.8 μm, respectively. In addition, the bending resistance of FD#2 and FD#3 is excellent, with bending losses of 0.003 dB/km and 0.001 dB/km at a bending radius of 8 cm. We also evaluated the manufacturing tolerance range of these two structures in the actual manufacturing process. The structure proposed in this paper is expected to provide new ideas for the design of nested elements, and provide more possibilities for optical fiber design suitable for large-capacity data transmission and gas sensing applications. [ABSTRACT FROM AUTHOR]

In this paper, a new and simple structure of a photonic crystal fiber (PCF) surface plasmon resonance biosensor is designed for detecting aqueous solutions. The graphene and magnesium fluoride (MgF2) materials are used externally around the PCF to increase the sensitivity of the sensor. The performance of the sensor is analyzed using the finite element method. The numerical results show that the proposed PCF provides an average wavelength sensitivity (Sw) and amplitude sensitivity (SA) as high as 4000 nm/RIU−1 and 16,905.15 RIU−1, respectively, for analytes with refractive indices (RIs) ranging from 1.33 to 1.342. When the MgF2 layer is eliminated from the structure, the values of Sw and SA are decreased to 2500 nm/RIU−1 and 12,155.2 RIU−1, respectively. Therefore, it is concluded that adding an MgF2 layer externally on the graphene layer of the proposed PCF increases the Sw and SA parameters. It is also exhibited that by increasing the thickness of graphene layers, the confinement loss is enhanced, and the SA is decreased. In addition, by adding the thickness of the MgF2, both SA and confinement loss parameters are increased. The results also show a linear relationship between the parameters with a very high figure of merit (FOM) of 17,416.66RIU−1 and a resolution of 2.5 × 10–5. [ABSTRACT FROM AUTHOR]

In this study, we propose a new design based on photonic crystal fibers (PCFs) for broadband dispersion compensation in telecommunication networks. The proposed design has a hexagonal structure arrangement of air-holes rings of different diameters between the silica core and the cladding. The PCF properties like effective area, nonlinearity, dispersion slope, confinement loss, and birefringence are reported and discussed. For the best performance we present three designs A, B and C. Simulation results show that the three designs cover the six-telecommunication optical bands O-, E-, S-, C-, L- and U- bands (wavelengths ranging from 1260 to 1675 nm). Design A achieves a large negative dispersion value of about − 1716 ps/(nm.km) with relative dispersion slope equals to that of conventional single-mode optical fibers (SMFs) of about 0.0036 nm−1, which makes it very suitable for long-haul DWDM transmission systems. With a little modification in the core, designs B and C achieve much higher confinement ability and achieve a very large birefringence value for polarization mode dispersion and sensing applications. Design C is engineered to have exact opposite dispersion of SMF with zero dispersion at the wavelength 1310 nm, which makes it a promising design in CWDM transmission system. The numerical values have been investigated using the full vector finite element method. [ABSTRACT FROM AUTHOR]

The present investigation examines a novel dual-core photonic crystal fiber (PCF) for early cancer cell detection that is based on a surface plasmon resonance (SPR) biosensor. The PCF is coated with Au/TiO2 layers to boost sensor effectiveness by enhancing the adhesion between the fiber and gold layers. The sensor was simulated and analyzed using the COMSOL Multiphysics software, which is based on the finite element method (FEM). Spectral and amplitude interrogations were used to explore the RI fluctuations of various cancer cells. The observed RI values varied within the range of 1.36–1.401. The biosensor's highest sensitivity was found to be 11,429 nm/RIU for MCF-7 cells using spectral interrogation and 1251.18 RIU−1 for MDA-MB231 cells utilizing amplitude interrogation techniques. Additionally, the sensor shows the maximum resolution for basal cells, which is 8.75 × 10−6 RIU. [ABSTRACT FROM AUTHOR]

Photonic crystals (PhCs) have gained attention for their ability to control and manipulate light at the nanoscale. They have led to advancements in optical communications, sensing and detection, and the development of novel optical devices. Specific examples include photonic crystal fibers for high-speed data transmission, ultrasensitive sensors for medical diagnostics, and compact wavelength filters and splitters. The articles in this Special Issue explore various applications and advancements in PhCs, offering valuable insights and possibilities for the future of optical devices. [Extracted from the article]

Given the ever‐increasing demand for transmission capacity in optical fiber communication systems, there is a growing focus on developing active fibers and devices with an optical response across a wider spectrum. Bismuth (Bi)‐doped photonic glasses have attracted significant interest for their exceptional ultra‐broadband optical response, particularly within telecommunication bands. However, developing advanced Bi‐activated materials with robust optical response, high compatibility with commercial transmission systems, and low processing temperature remains a huge challenge. Herein, an anion hybridization strategy is proposed to overcome the aforementioned limitations. The anion hybridization significantly enhances the broadband optical response (≈10 times) of the Bi center following the introduction of fluorine ions, and reduces the transition temperature of the photonic glass (≈200 °C). Moreover, the near‐infrared optical response bandwidth experiences significant broadening, a result attributed to the larger inhomogeneous broadening. Furthermore, successful fabrication of the anion‐hybridized Bi‐activated glass fiber is achieved, demonstrating excellent compatibility with commercial transmission fibers. Additionally, the fabricated fiber exhibits an amplified spontaneous emission and on‐off gain across a broad waveband, further validating its efficacy. These results indicate that anion hybridization offers an effective strategy to optimize the optical and thermal properties of photonic materials to develop novel advanced photonic devices. [ABSTRACT FROM AUTHOR]

We present a new design of three photonic crystal fibers (PCFs) made of fused silica glass, infiltrated with toluene (C7H8) with different lattices in cladding including circular lattice (CL), hexagonal lattice (HL) and square lattice (SL). The optimal structures that operate in the all-normal dispersion regime, were selected by investigating the dependence of the lattice parameters in the first ring surrounding the core on the PCF characteristics. In addition, we punctuate the possibility of coherent octave-wide supercontinuum (SC) generation in the wavelength range of 0.75–1.68 μ m, 0.76–1.91 μ m (1.3 μ m pump wavelength), and 0.65–1.45 μ m (1.064 μ m pump wavelength) with 90 fs pulses and 30 pJ of low energy in-coupled into the core of the selected PCFs. The highest SC generation efficiency is obtained with HL-PCF. The proposed fibers are good candidates for all-fiber SC sources, as a new source of SC light. [ABSTRACT FROM AUTHOR]