Glass Optical Fibers Research Articles

Silicate glass-ceramic fibers with nonlinear optical crystals: Evaluation of propagation loss and comparison to optical materials

Optical glass fibers can propagate light signals, while their control depends on nonlinear optical crystals. In this study, we fabricated nonlinear optical glass-ceramic (GC) fibers in which the polar fresnoite phase was crystallized based on perfect surface crystallization (PSC) in the SrO–TiO2–SiO2 system. GC fibers free from voids were obtained from precursor glass fibers with a diameter of ∼100 μm by controlling PSC. The propagation loss of a GC fiber was evaluated to be ∼0.37 dB/cm, which is comparable to that of the LiNbO3 single-crystal optical waveguide.

Piezotronic, ZnO Overlaid Bragg Grating Organic Vapor Sensors

We present a zinc oxide (ZnO) out-cladding, overlaid optical fiber Bragg grating sensor, for the detection of vapors of common alcohols and acetone at concentrations lower than 25 ppm while operating at room temperature (RT). The optical fiber sensing results indicate a chemostriction effect occurring in the ZnO layer when exposed to volatile organic compounds (VOCs), which in turn induces shifts in the cladding, and most importantly, in the core confined, Bragg mode. The sensor exhibits a maximum sensitivity of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim $ </tex-math></inline-formula> 1 pm/ppm to ethanol vapors, with exposure to other alcohol vapors (isopropanol and methanol) showing lower sensitivities; also, response to acetone vapors was traced at <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim $ </tex-math></inline-formula> 0.5 pm/ppm. X-ray diffraction (XRD) measurements of the ZnO nanolayer revealed that, in saturated ethanol vapors atmosphere, the polycrystalline ZnO film undergoes a contraction by 0.6% of the interplanar distance corresponding to the (002) crystalline direction, denoting the chemostrictive effect through an underlying piezotronic mechanism. XRD measurements and optical fiber sensing data are further correlated by numerical simulations carried out, so to study the strain interactions of the ZnO layer with the silica glass optical fiber.

Sensing of Magnetic-Field Gradients with Nanodiamonds on Optical Glass-Fiber Facets.

We demonstrate a photonic sensor of the magnetic field and its gradients with remote readout. The sensor is based on optically detected magnetic resonance (ODMR) in nanodiamonds with nitrogen-vacancy color centers that are covalently attached as a thin film on one facet of an optical fiber bundle. By measuring ODMR signals from a group of individual fibers in an ∼0.5-mm-wide imaging bundle, differences of local magnetic field strengths and magnetic field gradients are determined across the plane of the bundle facet. The measured gradients are created by direct electric currents flowing in a wire placed near the nanodiamond film. The measurement enabled the determination of the net magnetic field corresponding to various current directions and their corresponding magnetic field gradients. This demonstration opens up a perspective for compact fiber-based endoscopy, with additional avenues for remote and sensitive magnetic field detection with submicrometer spatial resolution under ambient conditions.

Effect of Yb3+/Er3+ co-doping on the emission properties of fluoroindate glass and glass optical fiber

In this study, a comprehensive analysis of emission in erbium-doped and erbium and ytterbium co-doped fluoroindate glasses has been presented. The luminescence of the erbium transitions and the effect of ytterbium co-doping under 488, 808 and 976 nm laser excitation have been discussed. Optimization of rare-earth (RE) ions doping concentration and the energy transfer processes related to the sensibilization effect in Er3+/Yb3+ co-doped fluoroindate glasses focusing on the reciprocal distribution of radiative transitions, energy transfer parameters, and lifetimes have been analyzed. The luminescence consists of several bands in the visible (525, 546 and 660 nm) and the infrared (1550 and 2700 nm) spectral regions that correspond to characteristic radiative energy transitions within the erbium ions. In glasses co-doped with the Er3+/Yb3+ system, an augmentation in the emission intensity was observed in the visible and at 1550 nm, while a decrease was observed in the 2700 nm infrared band. The increase of the Yb3+: 2F5/2 lifetime under 488, 808 and 976 nm excitation showed significant Er3+: 4I11/2 → Yb3+: 2F5/2 back energy transfer. Based on the analysis of the available literature, it can be concluded that energy transfer upconversion and cooperative energy upconversion play a significant role in modulating luminescence intensity values within the examined emission bands. This effect is likely enhanced due to the incorporation in a low phonon energy glass matrix. As a result of the above optimization, a glass optical fiber co-doped with 0.8 YbF3/1.4 ErF3 (in mol%) was drawn and characterized, showing a strong emission at 2.77 μm. The optimized Er3+/Yb3+ co-doped fluoroindate glass and glass optical fiber confirmed their ability to be used in the visible and near-infrared spectral regions as efficient optical fiber sources.

A Comparative Study of Plastic and Glass Optical Fibers for Reliable Home Networking

Home networking using fiber optics is essential for uninterrupted data transmission in modern communication networks. In this study, we evaluated and compared the reliability of plastic optical fibers (POFs) and glass optical fibers (GOFs) for home networking applications. Furthermore, assess the advantages and disadvantages of POF and GOF over short distances and find that POF is more suitable for home network applications due to its higher reliability. In addition, it has the advantage of being cost-effective and flexible for short-distance applications. The results show that POF indicates higher reliability and better performance at 8.25517 × 101of the Q factors, 2.21355 × 10−3 of the eye height, and 2.8307 × 10−3 of the threshold values at 30 meters, while GOF shows 6.30 × 101 of the Q factor, 3.78087 × 10−3 of the eye heights and 4.34736 × 10−3 of the threshold values. Moreover, this research highlights the importance of reliability in designing and applying optical fiber networks and can help network designers and engineers make informed decisions when selecting the appropriate type of optical fiber for specific applications.

Laser Welding of Fiber and Quartz Glass Ferrule.

Optical fiber sensors fabricated by bonding have several limitations. To address these limitations, a CO2 laser welding process for an optical fiber and quartz glass ferrule is proposed in this study. A deep penetration welding method with optimal penetration (penetrating the base material only) is presented to weld a workpiece according to the requirements of the optical fiber light transmission, size characteristics of the optical fiber, and the keyhole effect of the deep penetration laser welding. Moreover, the influence of laser action time on the keyhole penetration is studied. Finally, laser welding is performed with a frequency of 24 kHz, power of 60 W, and duty cycle of 80% for 0.9 s. Subsequently, the optical fiber is subjected to out-of-focus annealing (0.83 mm, 20% duty cycle). The results show that deep penetration welding produces a perfect welding spot and has good quality; the hole generated from deep penetration welding has a smooth surface; the fiber can bear a maximum tensile force of 1.766 N. The performance of the optical fiber sensor is stable, and the maximum pressure deviation corresponding to the cavity length fluctuation is about 7.2 Pa. Additionally, the linear correlation coefficient R of the sensor is 0.99998.

Development of Glass Optical Fibers 1970-2020, Providing Us the Digitalized Communication World

Development of Glass Optical Fibers 1970-2020, Providing Us the Digitalized Communication World

Progress on mid-infrared glass optical fiber materials and Raman laser source (invited)

Progress on mid-infrared glass optical fiber materials and Raman laser source (invited)

100 years of Brillouin scattering: Historical and future perspectives

The Year 2022 marks 100 years since Leon Brillouin predicted and theoretically described the interaction of optical waves with acoustic waves in a medium. Accordingly, this resonant multi-wave interaction is referred to as Brillouin scattering. Today, Brillouin scattering has found a multitude of applications, ranging from microscopy of biological tissue, remote sensing over many kilometers, and signal processing in compact photonic integrated circuits smaller than the size of a thumbnail. What allows Brillouin scattering to be harnessed over such different length scales and research domains are its unique underlying properties, namely, its narrow linewidth in the MHz range, a frequency shift in the GHz range, large frequency selective gain or loss, frequency tunability, and optical reconfigurability. Brillouin scattering is also a ubiquitous effect that can be observed in many different media, such as freely propagating in gases and liquids, as well as over long lengths of low-loss optical glass fibers or short semiconductor waveguides. A recent trend of Brillouin research focuses on micro-structured waveguides and integrated photonic platforms. The reduction in the size of waveguides allows tailoring the overlap between the optical and acoustic waves and promises many novel applications in a compact footprint. In this review article, we give an overview of the evolution and development of the field of Brillouin scattering over the last one hundred years toward current lines of active research. We provide the reader with a perspective of recent trends and challenges that demand further research efforts and give an outlook toward the future of this exciting and diverse research field.

Potential new material for optical fiber: Preparation and characterization of transparent fiber based on natural cellulosic fiber and epoxy

In order to reduce the dependence on fossil energy products, natural fiber/polymer hybrid composites have been increasingly researched. The high price of the quartz optical fibers and glass optical fibers has greatly inspired researchers to engage in the research on polymer optical fibers. Herein, transparent fibers based on plant fibers were innovatively prepared for the first time by delignification and impregnating epoxy diluted with acetone. The epoxy improved the thermal stability of the fiber without deteriorating its mechanical properties, and also endowed the fiber with the property of transparency. The tensile strength of transparent fibers of three diameters were 34.5, 58.6 and 100.3 MPa, respectively and the corresponding Young's modulus reached 1.1, 1.7 and 2.3 GPa, respectively. In addition, the light-conducting properties of transparent fibers were displayed with a green laser and the fibers displayed good light transmission along the fiber growth direction. Transparent fibers are expected to be used in optical fibers because of their high thermal stability, good mechanical properties and light-conducting properties.

Supercontinuum generation and IR image transportation using soft glass optical fibers: a review [Invited

Soft glass optical fibers, especially highly nonlinear optical fibers, have expanded their application fields. We have been engaged in soft glass optical fibers, such fluoride, tellurite and chalcogenide glass, for optical signal processing, lightwave generation and waveguide applications. Furthermore, we have challenged the research on novel waveguides, for example, transverse Anderson localization of mid-infrared light using transversely disordered optical fiber. Here we report our achievements on SC generation and novel waveguides research using the soft glass highly nonlinear optical fibers.

Oxide ion polarizability, optical basicity, and metallization criterion of GO-coated Nd2O3 (NPs) - TeO2 glass for linear optical fibre

The versatility of graphene oxide (GO) as coating materials on the glass surface is a new revolution in the advanced glass era. In this work, GO liquid solution was prepared by using electrochemical exfoliation in an electrolyte solution assisted by different surfactants. Meanwhile, a glass series was prepared by using the conventional meltquenched technique. A low-cost and simple spray deposition technique was used to deposit the GO on the glass sample. The obtained glass series was denoted as GO coated TNd (NPs), meanwhile, the uncoated glass was labelled as uncoated TNd (NPs). The linear optical properties of GO coated TNd (NPs) glass series was determined using UVVis spectrophotometer and utilizing the Lorentz-Lorentz equation to determine the value of polarizability. X-ray diffraction spectra revealed the amorphous structural characteristics of the glass series. The SEM morphological image revealed the variation of GO distribution on the glass surface due to the agglomeration and inhomogeneity of GO distribution on the glass surface. The homogeneity of GO distribution on the glass surface is negligible in this work as we focus solely on the effect of GO on glass properties. According to the observations, the value of GO-coated TNd (NPs) is in the range 3.4531- 3.8549 Å and uncoated TNd (NPs) is in the range 2.709- 2.774 Å. Meanwhile, the optical basicity value ranges from 1.220 to 1.262. These results demonstrate that the polarizability of oxide ions and optical basicity values of the GO coated TNd (NPs) glass series was higher than the uncoated TNd (NPs) glass. The metallization criterion for the GO-coated TNd (NPs) glass system is in the range of 0.3 &lt; M &lt; 0.4. Based on these results, the obtained glasses are promising in linear optical glass fibre.

Ultrafast fiber laser at 0.9 µm with a gigahertz fundamental repetition rate by a high gain Nd3+-doped phosphate glass fiber.

Fiber lasers, owing to the advantages of excellent beam quality and unique robustness, play a crucial role in lots of fields in modern society. Developing optical glass fibers with superior performance is of fundamental importance for wide applications of fiber lasers. Here, a new Nd3+-doped phosphate single-mode fiber that enables a high gain at 0.9 µm is designed and fabricated. Compared to previous Nd3+-doped silica fibers, the developed phosphate fiber exhibits a significant gain promotion, up to 2.7 dB cm-1 at 915 nm. Configuring in a continuous-wave fiber laser, this phosphate fiber can provide a slope efficiency of 11.2% in a length of only 4.5 cm, about 6 times higher than that of Nd3+-doped silica fiber. To showcase its uniqueness, an ultrafast fiber laser with ultrashort cavity is constructed, such that an ultrashort pulse train with a fundamental repetition rate of up to 1.2 GHz is successfully generated. To the best of our knowledge, this is the highest fundamental repetition rate for mode-locked fiber lasers at this wavelength range - two orders of magnitude higher than that of prior works. These results indicate that this Nd3+-doped phosphate fiber is an effective gain medium for fiber amplifiers and lasers at 0.9 µm, and it is promising for two-photon biophotonics that requires long-term operation with low phototoxicity.

On estimating axial strains using FBG sensors in single fiber composites

Several factors that impact the calculation of axial strain evolution using fiber Bragg grating (FBG) sensors during the manufacturing of tin/bismuth alloys, ice, and epoxies are investigated. Axial and radial strains in the embedded fiber are impacted by the elastic properties and relative volumes of the fiber and the matrix as well as by the aspect ratio of the fiber. Numerical and analytical composites evaluation approaches are used to determine the relationships between the strains in the fiber and those in the matrix. Radial strains in the fiber can have a significant impact on the Bragg wavelength shift and need consideration to accurately determine matrix strains, especially when the matrix has a high stiffness compared to the glass optical fiber containing the FBG sensors. For stiffer materials such as ice and tin/bismuth alloys investigated in this research, it is shown that the use of a simplified formula that ignores radial strains leads to significant errors.

Development of optical fibers and glasses for fibers—Evolution of optical fiber glasses from multicomponent to pure silica

Development of optical fibers and glasses for fibers—Evolution of optical fiber glasses from multicomponent to pure silica

Light-induced In Situ Transmission Electron Microscopy for Observation of the Liquid-Soft Matter Interaction.

The current protocol describes the modifications of the transmission electron microscope (TEM) setup for in situ light-induced observations. A glass optical fiber inserted into the electron column above the objective lens polepiece, and a laser, an adjustable light source, was used to fabricate the device. After the illuminator has been calibrated using an external measuring system, it allows one to adjust the intensity of the lighting to the needs of the observed process. This lighting system was utilized to image antimicrobial photodynamic therapy phenomena, which are currently the subject of intense research. The sample was prepared by spotting a suspension of bacteria on a carbon, graphene, or silicon nitride substrate, blotting the excess solution, spotting the photosensitizer solution, blotting the excess liquid again, and then assembling the liquid cell with a second substrate or graphene film. The process of the imaging experiment itself includes choosing the right place for observation with the use of low magnification and a minimum dose of electrons, and then cyclical activation of the light source to capture subsequent images at specified intervals with the minimum amount of electrons necessary. The electron dose of each exposure and the time and intensity of lighting used need to be carefully recorded due to the complexity of the observed phenomena as, at the same time, the process is both light- and electron-driven. After the actual experiment is performed, additional control observations must be made, in which the same doses of electrons are used but without additional light influence and smaller doses of electrons are used for higher doses of light. This makes it possible to distinguish light-induced microstructural effects from those caused by electrons in both the fields of life and materials science.

Fiber drawing ability and loss optimization of niobium rich borophosphate optical glass fibers

Here we explore the manufacturing of niobium-rich borophosphate glasses into fibers with optical quality. Glass preforms of composition [(100-x) (0.95 NaPO3 + 0.05 Na2B4O7) - x Nb2O5] with x = 37, 38, 39, 40 were synthetized and thermally drawn. Viscosity measurements performed in the softening point range show that the optical fiber drawing temperature gradually increases with the amount of niobium oxide. X-ray diffraction and Raman structural analysis performed post drawing demonstrate that the BPN glass with 39% Nb2O5 represents the upper limit for fiber drawing under oxygen. Subsequently, preform quenching protocol was optimized to mitigate the density fluctuations within the glass matrix related to convection flows and compare with the conventional cast-in-mold method. Optical transmission and shadowscopy imaging highlight the improvement in the optical quality of the glasses produced following this new protocol. This observation is confirmed by cut back loss measurements which show a decreasing in the attenuation from 6.04 dB/m to 3.19 dB/m between the two methods. One believes the manufacturing of niobium rich borophosphate fibers with improved optical quality highlights their potential to be used as near-infrared highly nonlinear waveguide devices.

Transparent Concrete (LiTraCon)

Abstract: This article especially covenant with the translucent concrete and also future advantages usage of smart construction world, usages of transparent concrete is a concrete based building material with having light-Trans missive properties due to embedded light optical elements usually Optical fibers. Light is conducted through the stone from one end to the other. Therefore the fibers are need to arrange through the whole object. Transparent concrete is also known as the translucent concrete and light transmitting concrete because of its properties. It is used in fine architecture as a front of building material and for cladding of interior walls. In this report, to integrate the merits of concrete and optical fiber, for developing transparent concrete by arranging the high numerical aperture Plastic Optical Fibers (POF) or big diameter glass optical fiber into concrete. The main purpose is to use sunlight as a light source to reduce the non-renewable energy consumption of illumination and to use the optical fibre to sense the stress of structures and also use this concrete as an architectural purpose for good aesthetic view of the building. The binding material in transparent concrete which is able to transmit light by using clear resins the concrete mix. The Paper circumscribe with the need of transparent concrete at present to utilize the sunlight and for architecture technologies. The new type of concrete can satisfy the green energy saving with its own Natural properties. The work presented in this project reports an investigation on the behaviour of concrete and mortar with optical fibre. Concrete and mortar cube are casted with fibers to study the properties and to compare the compressive strength between normal mix concrete with optical fibre and normal mortar with optical fibre after 7 days, 14 days and 28 days respectively. The compressive strength of concrete samples made with different fibre amount varies from 4% to 5% . The compressive strength of translucent concrete depends upon the amount of fibre content present. The samples with fibers of 4% showed better results in comparison with the others.

Calculation of the Coupling Coefficient in Step-Index Multimode Polymer Optical Fibers Based on the Far-Field Measurements

Using the power flow equation (PFE), this article investigates mode coupling in step-index (SI) multimode (MM) polymer optical fiber (POF). This equation’s coupling coefficient was initially fine-tuned so that it could appropriately reconstruct previously recorded far-field (FF) power distributions. The equilibrium mode distribution (EMD) and steady-state distribution (SSD) in the SI MM POF were found to be obtained at lengths Lc = 15 m and zs = 41 m, respectively. These lengths are substantially shorter than their glass optical fiber counterparts. Such characterization of the investigated POF can be used in its employment as a part of the communication or sensory system. Namely, the POF’s bandwidth is inverse linear function of fiber length (z−1) below the coupling length Lc. However, it has a z−1/2 dependence beyond this equilibrium length. Thus, the shorter the coupling length Lc, the sooner transition to the regime of slower bandwidth decrease occurs. It is also important to be able to determine a modal distribution at a certain length of the POF employed as a part of optical fiber sensory system.

Mode Coupling and Steady-State Distribution in Multimode Step-Index Organic Glass-Clad PMMA Fibers

Mode coupling and power diffusion in multimode step-index (SI) organic glass-clad (OGC) PMMA fiber is examined in this study using the power flow equation (PFE). Using our previously proposed approach we determine the coupling coefficient D for this fiber. When compared to standard multimode SI PMMA fibers, the multimode SI OGC PMMA fiber has similar mode coupling strength. As a result, the fiber length required to achieve the steady-state distribution (SSD) in SI OGC PMMA fibers is similar to that required in standard SI PMMA fibers. We have confirmed that optical fibers with a plastic core show more intense mode coupling than those with a glass core, regardless of the cladding material. These findings could be valuable in communication and sensory systems that use multimode SI OGC PMMA fiber. In this work, we have demonstrated a successful employment of our previously proposed method for determination of the coupling coefficient D in multimode SI OGC PMMA fiber. This method has already been successfully employed in the previous research of mode coupling in multimode SI glass optical fibers, SI PMMA fibers and SI plastic-clad silica optical fibers.