Study of the optical parameters of a silica-polymeric optical fiber with a reflective coating made of a thermoplastic fluoropolymer

2020 ◽  
Vol 86 (7) ◽  
pp. 27-32
Author(s):  
A. A. Zamyatin ◽  
A. A. Makovetskii ◽  
I. P. Shilov ◽  
D. V. Lapshin
Keyword(s):  
Laser Radiation ◽  
Optical Fiber ◽  
Numerical Aperture ◽  
Optical Loss ◽  
Fiber Surface ◽  
Optical Parameters ◽  
Core Diameter ◽  
Protective Function ◽  
Reflective Coating ◽  
Rough Turning

Silica optical fibers (OF) having a core diameter of 400 – 800 μm made of biocompatible materials are widely used in laser medicine. The results of studying the optical parameters of novel silica-polymeric optical fiber with a reflective thermoplastic copolymer coating (tetrafluoroethylene – ethylene) and the influence of coating conditions on these optical parameters are presented. Coatings from polymer melt were applied to the silica fiber surface by orifice drawing. The numerical aperture of the drawn OF was measured by distribution of the laser radiation emerging from OF in the far field. The optical losses were determined by the distribution of the radiation scattered by the reflective coating along the OF length. The scattering parameters of the laser radiation transmitted through OF were estimated by the intensity and indicatrix of scattering. We studied OF samples up to 50 m in length with a silica core of about 400 μm in diameter and reflective coating with a thickness of 70 – 90 μm, the reflective coating also performed a protective function. The quality of applied coating and optical parameters of the OF samples depended on the speed of fiber drawing (coating speed) Vd. A smooth coating was obtained at Vd ≤ 2 m/min. When Vd > 2 m/min the coating became rough, turning into the so-called «shark skin» at Vd = 6 m/min. Observed scattering of radiation passing through the studied OF samples was attributed to the polymer structure which contained both crystalline and amorphous phases with different values of the refractive index. The smallest scattering was observed in a smooth-coated OF. The total optical loss at a wavelength λ = 532 nm amounted to 300 – 720 dB/km (a nominal numerical aperture was 0.44). Short (1.5 – 3 m) OF samples were shown to provide a transmission of 80 – 93% of the input power.

scholarly journals Insights and Aspects to the Modeling of the Molten Core Method for Optical Fiber Fabrication

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2898 ◽  
Author(s):  
Cavillon ◽  
Dragic ◽  
Faugas ◽  
Hawkins ◽  
Ballato
Keyword(s):  
Optical Fiber ◽  
Numerical Aperture ◽  
Effective Area ◽  
Refractive Index Profile ◽  
Aluminosilicate Glass ◽  
Core Diameter ◽  
Fiber Core ◽  
Core Method ◽  
Core Composition ◽  
Underlying Mechanisms

The molten core method (MCM) is a versatile technique to fabricate a wide variety of optical fiber core compositions ranging from novel glasses to crystalline semiconductors. One common feature of the MCM is an interaction between the molten core and softened glass cladding during the draw process, which often leads to compositional modification between the original preform and the drawn fiber. This causes the final fiber core diameter, core composition, and associated refractive index profile to vary over time and longitudinally along the fiber. Though not always detrimental to performance, these variations must, nonetheless, be anticipated and controlled as they directly impact fiber properties (e.g., numerical aperture, effective area). As an exemplar to better understand the underlying mechanisms, a silica-cladding, YAG-derived yttrium aluminosilicate glass optical fiber was fabricated and its properties (core diameter, silica concentration profile) were monitored as a function of draw time/length. It was found that diffusion-controlled dissolution of silica into the molten core agreed well with the observations. Following this, a set of first order kinetics equations and diffusion equation using Fick’s second law was employed as an initial effort to model the evolution of fiber core diameter and compositional profile with time. From these trends, further insights into other compositional systems and control schemes are provided.

Application of Optical Fiber Made of Various Materials with Composite Properties of Materials in Laser Medical Treatment

2012 ◽  
Vol 600 ◽  
pp. 222-225
Author(s):  
Zhen Zhang ◽  
Fang Liu
Keyword(s):  
Optical Fiber ◽  
Medical Treatment ◽  
Plastic Material ◽  
Numerical Aperture ◽  
Fiber Material ◽  
Spot Size ◽  
Light Transmittance ◽  
Core Diameter ◽  
Transmission Distance ◽  
Fiber Manufacturing

Though introducing the optical fiber in a laser medical treatment made ​​of different materials, contrast expounded integrated characteristic of the different materials in manufacturing an optical fiber material, summed four aspects need to be considered in the choice of the optical fiber manufacturing material. First, the laser parameters, such as maximum laser power, the wavelength, the transmission distance, the laser beam spot size and numerical aperture of the laser light source. Second, according to the optical fiber light transmittance curve, to identify the optimum transmittance of the application wavelength. Third, determining transmission optical slender core diameter, typically a core diameter is greater than the laser spot size of 2/3; decision sets of plastic material finally.

Technique for measuring laser radiation intensity in biological tissues

2013 ◽  
Vol 2 (3) ◽  
Author(s):  
Pavel Grachev ◽  
Victor Loschenov
Keyword(s):  
Laser Radiation ◽  
Optical Fiber ◽  
Radiation Intensity ◽  
Light Propagation ◽  
Continuous Wave ◽  
Biological Tissues ◽  
Optical Parameters ◽  
Laser Radiation Intensity ◽  
Transmitted Radiation ◽  
Tissue Surface

AbstractLaser methods, such as laser-induced fluorescence diagnostics, photodynamic therapy (PDT), and hyperthermia, are finding increasing use in medicine. Irradiation can be performed both with and without contact on the tissue surface. In the case of contact irradiation, especially when laser radiation is introduced into biological tissue through an optical fiber, it is important to know the processes taking place at the irradiation fiber end. These processes affect diffusely reflected radiation which returns to the fiber. By analyzing backscattered radiation, we can evaluate the quality of the radiation procedure and the state of the fiber end. The objectives of this study were to develop a method and device for measuring backscattered radiation power and using this method, to determine the time and temperature ranges realized in PDT and hyperthermia.Light propagation is discussed in bent optical fibers. A technique is proposed for measuring laser radiation intensity in the optical fiber bend. Based on this technique, a system was developed for monitoring the laser radiation dose absorbed in biological tissues. We studied samples of bovine liver, muscle and brain tissues. Experiments were performed using a 675 nm, 100–2200 mW continuous wave semi-conductor laser. Laser radiation was delivered through a silica/polymer optical fiber. Data concerning the temperature and transmitted radiation intensity was acquired.Modeling of the light propagation in a bent optical fiber showed that the sensitivity of the method depends on the position of the photodetectors, but is independent of the loop number of the optical fiber. The results of experiments are presented using different types of biological tissues. We obtained the experimental dependencies of backward and transmitted radiation intensities and the temperature of the tissue surface in the irradiated region on the irradiation time measured with a flat-end fiber. The characteristic ranges of tissue heating caused by irradiation were determined for use in clinical practice.The optical parameters of biological tissues change with increasing temperature. This affects the intensity of transmitting radiation and diffuse radiation entering the fiber. The change in the backscattered radiation intensity greatly depend on the temperature of the irradiated area. The control of the irradiation of biological objects provides an efficient delivery of laser radiation to biological tissues and increases hyperthermia and PDT treatment effect.

scholarly journals Optical Fiber Biomedical Sensor Based on Surface Plasmon Resonance

2020 ◽  
pp. 1650-1656
Author(s):  
Namaa Salem Rahim ◽  
Sudad S. Ahmed ◽  
Murtadha Faaiz Sultan
Keyword(s):  
Surface Plasmon Resonance ◽  
Optical Fiber ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Figure Of Merit ◽  
Work Performance ◽  
Signal To Noise Ratio ◽  
Numerical Aperture ◽  
Core Diameter ◽  
Biomedical Sensor

Optical fiber biomedical sensor based on surface plasmon resonance for measuring and sensing the concentration and the refractive index of sugar in blood serum is designed and implemented during this work. Performance properties such as signal to noise ratio (SNR), sensitivity, resolution and the figure of merit were evaluated for the fabricated sensor. It was found that the sensitivity of the optical fiber-based SPR sensor with 40 nm thick and 10 mm long Au metal film of the exposed sensing region is 7.5µm/RIU, SNR is 0.697, figure of merit is 87.2 and resolution is 0.00026. The sort of optical fiber utilized in this work is plastic optical fiber with a core diameter of 980 µm, a cladding of 20μm, and a numerical aperture of 0.51.

scholarly journals Surface Plasmon Plastic Optical Fiber Resonance with Multi-Layer as Chemical Sensor

2021 ◽  
Vol 19 (50) ◽  
pp. 51-59
Author(s):  
Emad Khatar ◽  
Sudad Salman Bassam
Keyword(s):  
Optical Fiber ◽  
Surface Plasmon ◽  
Figure Of Merit ◽  
Chemical Sensor ◽  
Signal To Noise Ratio ◽  
Optical Fiber Sensor ◽  
Numerical Aperture ◽  
Plastic Optical Fiber ◽  
Core Diameter ◽  
Chemical Materials

A chemical optical fiber sensor based on surface plasmon resonance (SPR) was developed and implemented using multimode plastic optical fiber. The sensor is used to detect and measure the refractive index and concentration of various chemical materials (Urea, Ammonia, Formaldehyde and Sulfuric acid) as well as to evaluate the performance parameters such as sensitivity, signal to noise ratio, resolution and figure of merit. It  was noticed that the value of the sensitivity of the optical fiber-based SPR sensor, with 60nm and 10 mm long, Aluminum(Al) and Gold (Au) metals film exposed sensing region, was 4.4 μm, while the SNR was 0.20, figure of merit was 20 and resolution 0.00045. In this work a multimode plastic optical fiber with a core diameter of 980 μm, fluorinated polymer cladding of 20 μm and a numerical aperture of 0.51 was used.

scholarly journals Fabrication of a Chemical Sensor Based on Surface Plasmon Resonance via Plastic Optical Fiber

2020 ◽  
pp. 765-771
Author(s):  
Ghufran Mohammed Jassam ◽  
Soudad S. Al–Bassam ◽  
Murtadha F. Sultan
Keyword(s):  
Surface Plasmon Resonance ◽  
Optical Fiber ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Figure Of Merit ◽  
Chemical Sensor ◽  
Optical Fiber Sensor ◽  
Numerical Aperture ◽  
Plastic Optical Fiber ◽  
Core Diameter

In this work, a chemical optical fiber sensor based on Surface Plasmon Resonance (SPR) was designed and implemented using plastic optical fiber. The sensor is used for estimating refractive indices and concentrations of various chemical materials (methanol, distilled water, ethanol, kerosene) as well as for evaluating the performance parameters such as sensitivity, signal to noise ratio, resolution and the figure of merit of the fabricated sensor. It was found that the value of the sensitivity of the optical fiber-based SPR sensor, with 40 nm thick and 10 mm long Au metal film of exposed sensing region, was 3μm/RIU, while the SNR was 0.24, the figure of merit was 20, and the resolution was 0.00066. The sort of optical fiber utilized in this work is plastic optical fiber with a core diameter of 980 μm, a fluorinated polymer cladding of 20μm and a numerical aperture of 0.51.

Fabrication of Lensed Plastic Optical Fiber Array Using Electrostatic Force

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
Yih-Tun Tseng ◽  
Jhong-Bin Huang ◽  
Che-Hsin Lin ◽  
Chin-Lung Chen ◽  
Wood-Hi Cheng
Keyword(s):  
Optical Fiber ◽  
Optical Fibers ◽  
Electrostatic Force ◽  
Coupling Efficiency ◽  
Numerical Aperture ◽  
Uv Curing ◽  
Power Budget ◽  
Fiber Array ◽  
Plastic Optical Fibers ◽  
Efficient Coupling

The GI (graded-index) POFs (Plastic optical fibers), which has been proven to reach distances as long as 1 km at 1.25 Gb/s has a relatively low numerical aperture . Therefore, the efficient coupling of GI POFs to the light source has become critical to the power budget in the system. Efficient coupling for a POFs system normally involves either a separate lens or the direct formation of the lens at the end of the fiber. Forming the lens-like structure directly on the fiber end is preferred for simplicity of fabrication and packaging, such as polishing and fusion, combine different fibers with the cascaded fiber method and hydroflouride (HF) chemical etching. These approaches are well established, but applicable only to glass. Optical assembly architecture for multichannel fibers and optical devices is critical to optical fiber interconnections. Multichannel fiber-pigtail laser diode (LD) modules have potential for supporting higher data throughput and longer transmission distances. However, to be of practical use, these modules must be more precise. This work proposes and manufactures lensed plastic optical fibers (LPOF) array. This novel manipulation can be utilized to fabricate an aspherical lens on a fiber array after the UV curing of the photo-sensitive polymer; the coupling efficiency (CE) is increased and exceeds 47% between the LD array and the fiber array.

Heat Transfer in Chemical Vapor Deposited Optical Fiber Coatings

2001 ◽  
Author(s):  
Patricia O. Iwanik ◽  
Wilson K. S. Chiu
Keyword(s):  
Heat Transfer ◽  
Optical Fiber ◽  
Gas Flow ◽  
Convection Heat Transfer ◽  
Fiber Surface ◽  
Chemical Vapor ◽  
Temperature Changes ◽  
Flow And Heat Transfer ◽  
Chemical Vapor Deposited ◽  
Fiber Coatings

Abstract A fundamental understanding of how reactor parameters influence the fiber surface temperature is essential to manufacturing high quality optical fiber coatings by chemical vapor deposition (CVD). In an attempt to better understand this process, a finite volume model has been developed to study the gas flow and heat transfer of an optical fiber as it travels through a CVD reactor. This study showed that draw speed significantly affects fiber temperature inside the reactor, with temperature changes up to 45% observed under the conditions studied. Multiple heat transfer modes contribute to this phenomena, with convection heat transfer dominating the process.

Sign in / Sign up

Export Citation Format

Share Document