Glass Optical Fibers Research Articles

Fluoride glass Raman fiber laser at 2185 nm

We report on the first Raman laser based on a fluoride glass optical fiber. The Raman fiber laser was pumped by a 9.6 WTm3+:silica CW fiber laser operating at a wavelength of 1940 nm. A maximum output power of 580 mW was measured at 2185.1 nm, corresponding to a frequency shift of 579 cm(-1) (17.37 THz). We observed a threshold power of 3.8 W and a low power slope efficiency of 29% with respect to the launched pump power. Using those results and the known fiber parameters, we estimated a Raman gain peak value of 3.52*10(-14) m/W, which is lower than the previously reported values.

A Prospective for New Mid‐Infrared Medical Endoscopy Using Chalcogenide Glasses

That chalcogenide glasses potentially provide a solution for mid‐infrared medical endoscopy is discussed in detail for the first time. It is shown that chalcogenide glass fiber optics could underpin new mid‐infrared medical endoscopic systems for real‐time molecular sensing, imaging, and analysis of tissue and for fiber laser surgery at new mid‐infrared wavelengths. Moreover, chalcogenide glass fiber optic and waveguide devices and systems could provide the key to new mid‐infrared communications for molecular sensing to inform decision‐taking in other sectors as diverse as manufacturing, energy, the environment, and security. The development and deployment of chalcogenide glasses for mid‐infrared photonics over the next decade or so could mirror the complexity and versatility of silica fiber optics developed in the 20th century for near‐infrared photonics. These ideas are developed in this article and the current status of chalcogenide glass photonics is briefly surveyed.

Single‐Cell‐Level Microplasma Cancer Therapy

A flexible microplasma endoscope based on a 15 μm hollow-core glass optical fiber is fabricated, and tumor cell apoptotic analysis supports its potential use in targeted cancer therapies. The optical-fiber microplasma jet reveals antitumor activity at a certain plasma dose in animal studies.

Suspended core tellurite glass optical fibers for infrared supercontinuum generation

We report the fabrication and characterization of tellurite TeO 2–ZnO–Na 2O (TZN) microstructured suspended core optical fibers (MOFs). These fibers are designed for infrared supercontinuum generation with zero dispersion wavelength (ZDW) at 1.45 μm. The measured losses at this wavelength are approximately 6 dB/m for a MOF with a 2.2 μm diameter core. The effective area of a particular fiber is 3.5 μm 2 and the nonlinear coefficient is calculated to be 437 W −1km −1. By pumping a 20 cm long fiber at 1.56 μm with a sub-nJ femtosecond laser source, we generate a supercontinuum (SC) spanning over 800 nm in the 1–2 μm wavelength range.

Biosensors based on combined optical and electrochemical transduction for molecular diagnostics

Electrochemical and optical biosensors exist to monitor different fluids containing analytes of interest. Until today, these have been developed separately. Owing to the creation of new transducer configurations such as indium tin-coated glass fiber optics, these methods can now be used separately, in parallel and it is hoped that one day they will be able to be used simultaneously; thus, using the same probe to measure a single analyte using two different methods (electrochemical and optical) or two different analytes with either of the aforementioned methods sitting on the same probe. This article will highlight the importance, as well as the usefulness, of combining measurement methodologies in improving sensor response and sensitivity.

Er-doped and Er, Yb co-doped oxyfluoride glasses and glass–ceramics, structural and optical properties

The selected glasses and glass–ceramics pertinent to following chemical composition in mol%:48%SiO 2–11%Al 2O 3–7%Na 2O–10%CaO–10%PbO–11%PbF 2–3%ErF 3 and 48%SiO 2–11%Al 2O 3–7%Na 2O–10%CaO–10%PbO–10%PbF 2–1%ErF 3–3%YbF 3 have been manufactured from high purity components (Aldrich) at 1450 °C in normal atmosphere. Glass optical fibers were successfully drawn. Subsequently they were subject to the heat-treatment at 700 °C in various time periods. The preceding differential thermal analysis (DTA) studies allowed estimating both the fiber drawing temperature and the controlled crystallization temperature of glass fibers. It has been observed that the controlled heat-treatment of oxyfluoride glass fibers results in the creation of Pb 5Al 3F 19, Er 4F 2O 11Si 3 and Er 3FO 10Si 3 crystalline phases. The identified phases were characterized by X-ray powder diffraction (XRD) and confirmed by selected area electron diffraction (SAED). The fibers consist of mixed amorphous–crystalline microstructure with nano-crystals of size even below 10 nm distributed in the glassy host. Their morphology was investigated applying high-resolution transmission electron microscopy. Optical properties and excited state relaxation dynamics of optically active ions (Er 3+, Yb 3+) in glass and glass–ceramics have been studied. Based on absorption spectra the Judd–Ofelt analysis was carried out. The main attention was directed to NIR luminescence at. 1.6 μm related to 4I 13/2 → 4I 15/2 Er 3+ and less effective emission associated with 4I 11/2 → 4I 15/2 Er 3+ and 2F 5/2 → 2F 7/2 Yb 3+ transitions. The dissimilar spectroscopic properties have been revealed for glasses and glass–ceramic samples, respectively. The reduction of emission linewidth at 1.6 and 1.0 μm combined with substantial increase of 4I 13/2 lifetimes of erbium in glass–ceramics appear to be evidences that Er 3+ ions are accommodated in crystalline phases. The structural and optical characteristics of oxyfluoride glass–ceramic fibers indicate that these optical systems may be considered as promising materials for Er-doped optical amplifiers operating within third telecommunication window.

Non-monotonous refractive index changes recorded in a phosphate glass optical fibre using 248nm, 500fs laser radiation

Results are presented on the photosensitivity behavior of a phosphate glass optical fibre using 248nm, 500fs laser radiation. Bragg grating exposures performed using a double phase mask interferometer and peak intensities of 0.37TW/cm2, revealed that grating growth becomes non-monotonic in terms of average and modulated refractive index changes, resembling the Type IIA photosensitivity behavior. Average refractive index changes greater than 10−3 were measured after accumulated energy density doses of 6.5KJ/cm2. The Bragg gratings inscribed maintained significant part of their strength up to 377°C. Exposed and side-polished fibre samples were subjected to Knoop micro-hardness measurements for revealing that the irradiated glass undergoes significant volume dilation.

Neurosensory tissue morphology with intraoperative optical fiber probe in aqueous medium

In this work, the author has demonstrated cross-sectional imaging of a retina of an ex vivo fish sample using a common path frequency domain optical coherence tomography at 0.8 μm range. It has been introduced that an integrated surgical hypodermic needle fiber probe can stabilize the flexible glass optical fiber and provides a close proximity to the specimen for intraoperative image guiding. In addition, the light source characteristics were matched to the common path interferometer while operating in the aqueous medium (saline solution), in order to mimic the in vivo condition, in that it shows greater bandwidth and shorter center wavelength for larger input current or output power to sustain the appropriate level of coherence reference peak by the partial reflection at the glass fiber probe interface.

A Review of Neuroendoscopy and Potential Applications in Veterinary Medicine

The endoscope was first developed over 200 yr ago. Endoscopy has since been applied to many disciplines of medicine. Its application to the nervous system was initially slow and not widely accepted and mainly involved the biopsy of tumors and the treatment of hydrocephalus. Several reasons for neuroendoscopy's limited use include inadequate endoscope technology, high skill level required, the advent of the surgical microscope, and the development of other treatments such as ventricular shunting. Over the past 50 yr, improvements in optical glass lenses, fiber optics, and electrical circuitry has led to better equipment and a revival of neuroendoscopy. Neuroendoscopy is now used in many diseases in human medicine including hydrocephalus, neoplasia, and intracranial cysts. This review presents the history of neuroendoscopy, the equipment and technology used, and the possible translation of techniques currently used in human medicine to veterinary medicine.

Transmission of Ultrasonic Waves Via Optical Silica Glass Fiber Doped by 7.5% of TiO2 with the Use of Power Sandwich Transducer

Abstract The possibility of acoustic wave propagation in optical waveguides creates new prospects for simultaneous transmission of laser beams and ultrasonic waves. Combined laser-ultrasonic technology could be useful in e.g. surgical treatment. The article presents the results of experimental studies of transmission of ultrasonic wave in optical fibres, the core of which is doped by 7.5% of TiO2, using a sandwich-type transducer. It also presents amplitude characteristics of an ultrasonic signal propagated in the optical fibre. Authors studied the effect which the length of the fibre has on the achieved output signal amplitudes. They presented the relation of the output signal amplitude from a capacitive sensor to the power applied to the sandwich-type transducer. The obtained results were compared with the results produced when using an optical fibre with a core doped by 3% of GeO2, in order to select optical fibre suitable for simultaneous transmission of ultrasonic waves and laser rays.

Accurate Determination of System Compliance and Young’s Modulus for Single Fibers

Abstract Single fiber testing was conducted utilizing the ASTM D3379-89e1 standard to measure the Young’s modulus for optical glass fibers. Upon analyzing the experimental data, it was discovered that procedural methods to account for system compliance resulted in a source of uncertainty due to the 12.6 % fiber diameter variability between different fibers tested. As a result, the 86.8 GPa Young’s modulus determined included a significant 43.9 % uncertainty. A new method of data analysis was devised to take into account this fiber diameter variability, which lowered the uncertainty to 7.5 % and provided a Young’s modulus of 61.4 GPa. Comparisons were made with the more recent ASTM C1557-03 standard that gave a similar 61.3 GPa Young’s modulus. A large bias error of 41.6 % exists between the Young’s modulus values determined by the two standard methods. The various analytical methods are discussed along with their estimates of uncertainty, the impact on micro-mechanics, and how to lower this uncertainty further.

Fabrication of highly nonlinear germano-silicate glass optical fiber incorporated with PbTe semiconductor quantum dots using atomization doping process and its optical nonlinearity

Germano-silicate glass optical fiber incorporated with PbTe semiconductor quantum dots (SQDs) in the core was fabricated by using the atomization process in modified chemical vapor deposition (MCVD) process. The absorption bands attributed to PbTe semiconductor quantum dots in the fiber core were found to appear at around 687 nm and 1055 nm. The nonlinear refractive index measured by the long-period fiber grating (LPG) pair method upon pumping with laser diode at 976.4 nm was estimated to be ~1.5 × 10(-16) m2/W.

J044024 電子線照射による長距離伝送用光ファイバーの引張強度評価([J04402]知的材料・構造システム(2))

Optical fibers are generally applied to the digital communication. It can transmit a high-speed signal in a extra-fine signal line without being affected by the electromagnetism. Therefore, the optical fiber cable are installed in the bottom of the sea to offer stable digital communication. However, the fibers are very fragile. It is a serious problem that the great labor is necessary in the restoration, as the glass optical fiber is damaged in the bottom of the sea. On the other hand, as for the silica glass which is the materials of the glass optical fiber, improvement of the impact value has been confirmed by minute treatments performing electron beam (EB) irradiation from the past study. Therefore, the effects of EB irradiation on tensile strength on glass optical fibers have been investigated. The EB irradiation improves the tensile strength and tensile elasticity.

Recent advances in preparation of high-purity glasses based on arsenic chalcogenides for fiber optics

The processes of production of high-purity glasses based on arsenic chalcogenides and optical fibers with low optical losses in the middle IR have been analyzed. Physical–chemical, technological and methodological factors determining the degree of purity of glasses and the level of optical losses in optical fibers are considered. Dominant factors, rational actions and approaches optimizing the manifestation of these factors in glasses formed by arsenic chalcogenides are discussed. Vitreous As 2S 3 is produced with the content of hydroxyl groups not more than 1 ppb wt, of hydrogen in the form of SH-groups — 75 ppb mol, of silicon — 0.2 ppm wt. From this glass a multi-mode optical fiber was manufactured with optical losses of 12 and 14 dB/km at 3.0 and 4.8 μm, respectively, which is the best result published in literature for chalcogenide glass optical fibers.

NONLINEAR OPTICAL PROPERTIES OF ZINC DOPED GERMANO-SILICATE GLASS OPTICAL FIBER

Zinc doped germano-silicate glass optical fiber was developed by using the modified chemical vapor deposition and the drawing tower process. Absorption peaks of the germano-silicate glass optical fiber preform appeared at 240 nm and 330 nm were due to the incorporated Zn metal nano-particles (MNPs) and ZnO semiconductor nano-particles (SNPs), respectively and the average diameter of nano-particles (NPs) was estimated to be about 2 nm by transmission electron microscopy. However, the absorption peak of the zinc doped optical fiber due to ZnO SNPs was found to appear at 490 nm red-shifted from 330 nm can be explained by the increase in average size of ZnO SNPs in the fiber core due to growth or recrystallization of ZnO SNPs during the fiber drawing process about 2150°C. The nonlinear refractive index coefficient, n2, of the fiber was estimated to be 5.62 × 10-20 m2/W due to the stable dispersion of ZnO SNPs using the continuous-wave self-phase modulation method.

Progress in low‐loss and high‐bandwidth plastic optical fibers

AbstractPlastic optical fibers (POFs) are highly promising transmission media for future home networking.In comparison to glass optical fibers (GOFs), which are commonly used in core and metropolitan networks, POFs offer many advantages such as great flexibility and easy handling. This review begins with the basic concepts of optical fibers and moves on to the early history of loss reduction in POFs. What drastically changed the status of POFs in the communications field was a graded‐index technology that improved the bandwidth to over 1 gigabits per second. However, even after the loss and bandwidth were enhanced to their limits, the performances of POFs were insufficient for market demand when using conventional optical polymer materials such as poly(methyl methacrylate). Recently, this problem has been solved by several lines of material research using fluorinated polymers. As a result, high‐speed optical home networking by POFs has become more realistic. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011

Luminol-Doped Nanostructured Composite Materials for Chemiluminescent Sensing of Hydrogen Peroxide

Silica based nanostructured composite materials doped with luminol and cobalt(II) ion were synthesized and characterized, resulting in a highly chemiluminescent material in the presence of hydrogen peroxide. A detection system with the CL light guided from the reaction tube to the photomultiplier tube using a one millimeter glass optical fiber was developed and assessed. A linear response was observed using a semi-logarithm calibration between 50–2000 μM hydrogen peroxide with 1 μM as the limit of detection.

Glass for obtaining rigid optic fibers

The effect of rare-earth oxides (WO 3 , Gd 2 O 3 , Y 2 O 3 ) on technological and physical-chemical characteristics of optical glasses for light-guiding fiber cores is investigated. Glass compositions for optical glass fiber which satisfy the main requirements imposed on them are synthesized. The glass compositions indicated can be used to produce fiber-optic articles.

Mode coupling in strained and unstrained step-index glass optical fibers

By using the power flow equation, we have examined the state of mode coupling in strained and unstrained step-index glass optical fibers. Strained fibers show stronger mode coupling than their unstrained counterparts of the same type. As a result, the coupling length where equilibrium mode distribution is achieved and the length of fiber required for achieving the steady-state mode distribution are shorter for strained than for unstrained fibers.

Enhanced Sensitivity of the FBG Temperature Sensor Based on the PbO-GeO$_{2}$-SiO$_{2}$ Glass Optical Fiber

We developed and demonstrated a highly sensitive fiber Bragg grating (FBG) temperature sensor by using the PbO-GeO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> glass optical fiber. Temperature sensitivity of the FBG sensor based on the PbO-GeO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> glass optical fiber was about 40% improved to the 0.0173 nm/°C by the thermal expansion increase of the fiber.