Quartz-quartz type light guides with low losses and a thin polymer shell for the near-IR spectral range.

The issues of obtaining silica optical fibers with SiO2/SiO2-F composition (where SiO2 is a core, and SiO2-F is a light-reflecting cladding) with low optical losses for the near-IR spectral range are considered. This fiber type is widely used in various fields of science and technology, including laser medicine. The study results of the dependence of the numerical aperture and fluorine concentration in silica glass of the formed fiber preforms on the Freon (C3F8) consumption in the gas phase when using a waveguide-type microwave plasmotron at the H10 wavelength, are presented. It is showed that to increase the fluorimeters sensitivity in the near-IR spectral range as probe fibers for detecting luminescence, it is promising to use quartz-quartz fibers with the “Heraeus” glass core and the reflective SiO2-F cladding with an increased fluorine content in the glass (up to 7 wt. %). In this case, the numerical aperture of such fibers will reach values up to 0.32. For laser procedures in ophthalmology, surgery, phlebology and etc., optical fibers with a standard numerical aperture 0.20-0.24 can be used (with a fluorine concentration in the glass up to 3 wt. %).

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Исследование оптических свойств многомодового кварцевого оптического волокна с отражающей оболочкой из фторированного термопластичного полимера

Журнал технической физики ◽

10.21883/os.2019.09.48206.107-19 ◽

2019 ◽

Vol 127 (9) ◽

pp. 477

Author(s):

А.А. Маковецкий ◽

А.А. Замятин ◽

Д.В. Ряховский

Keyword(s):

Optical Properties ◽

Optical Fiber ◽

Optical Fibers ◽

Scattered Radiation ◽

Fiber Length ◽

Numerical Aperture ◽

Optical Losses ◽

Laser Medicine ◽

Propagation Of Light ◽

Absorption Of Light

Optical properties silica - polymeric optical fiber with a core with a diameter of 430 microns and the reflecting cover 70 microns thick from thermoplastic copolymer of a tetraftoretilen with ethylene (Tefzel brand) are experimentally investigated. The polymeric cover is applied on silica fiber with applicator from polimer melt directly on drowing tower. Optical losses of the fiber, a numerical aperture and its dependence on fiber length are measured. It is established that at propagation of light in fiber its noticeable scattering is observed. It is connected with crystallinity of polymeric cover. Distribution of intensity of scattered radiation along an axis of fiber and an indicatrix of dispersion of radiation by a coating are measured. Relative deposits of dispersion and absorption of light in a cover at the general optical losses of fiber are estimated. The possibility of use of optical fibers of this structure in laser medicine is considered.

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Results of Spatial Structure of Atmosphere Radiation in a Spectral Range (1.5–2) µm Research

Light & Engineering ◽

10.33383/2017-061 ◽

2018 ◽

pp. 7-13

Author(s):

Anton M. Mishchenko ◽

Sergei S. Rachkovsky ◽

Vladimir A. Smolin ◽

Igor V . Yakimenko

Keyword(s):

Spatial Structure ◽

Unmanned Aerial Vehicle ◽

Wavelength Range ◽

Spectral Range ◽

Near Ir ◽

Optoelectronic Systems ◽

Aerial Vehicle

Results of experimental studying radiation spatial structure of atmosphere background nonuniformities and of an unmanned aerial vehicle being the detection object are presented. The question on a possibility of its detection using optoelectronic systems against the background of a cloudy field in the near IR wavelength range is also considered.

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Possible Effect of Human-Experimenter on Homeopathic-Like Aqueous Preparations

Water ◽

10.3390/w13111475 ◽

2021 ◽

Vol 13 (11) ◽

pp. 1475

Author(s):

Vladimir Korenbaum ◽

Tatiana Chernysheva ◽

Victorya Galay ◽

Roman Galay ◽

Alexandr Ustinov ◽

...

Keyword(s):

Statistical Analysis ◽

Light Scattering ◽

Dynamic Light Scattering ◽

Spectral Range ◽

Placebo Effect ◽

Measuring Process ◽

Observer Effect ◽

Spectral Changes ◽

Near Ir ◽

Patient Side

Homeopathy is one of the applications in structured water influencing human health. The objective is to search for the physical basis of homeopathy. This methodology includes a study of absorption in the far IR spectral range, absorption and refraction in THz diapason, dynamic light scattering in the UV–near IR spectral range for the blinded samples of homeopathic-like preparations (HLP) of several parent substances and hidden/apparent controls, and statistical analysis on the significance of distinctions in spectral data between ensembles of HLP of each parent substance and ensembles of hidden/apparent controls. The analysis of nine independent blind studies of aqueous HLP of several parent substances gave statistically significant spectral differences in some preparations with an apparent control (25 comparisons of 35) and a hidden control (11 comparisons of 40). The revealed dominance in the occurrence frequency of differences in any HLP with an apparent control can be treated as involving most of these changes to the samples by the spectral measuring process. This allows interpreting the main mechanism of manifestation of the spectral changes found as the “observer effect”. The therapeutic effect of HLP may be assumed as a combination of the “observer effect” from the physician side and a “placebo effect” from the patient side.

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Measurement of Laser Radiation Attenuation in Metallized Optical Fibers in Visible and Near-IR Spectral Ranges

2020 International Conference Laser Optics (ICLO) ◽

10.1109/iclo48556.2020.9285567 ◽

2020 ◽

Author(s):

P.S. Cherpak ◽

R.I. Shaidullin ◽

O.A. Ryabushkin

Keyword(s):

Laser Radiation ◽

Optical Fibers ◽

Radiation Attenuation ◽

Near Ir ◽

Spectral Ranges

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Dispersion properties of single-mode optical fibers in telecommunication region: poly (methyl methacrylate) (PMMA) versus silica

Journal of Optical Communications ◽

10.1515/joc-2020-0172 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

Hassan Pakarzadeh ◽

Seyed Mostafa Rezaei ◽

Mostafa Taghizadeh ◽

Forough Bozorgzadeh

Keyword(s):

Methyl Methacrylate ◽

Optical Fibers ◽

Spectral Range ◽

Structural Parameters ◽

Practical Importance ◽

Single Mode ◽

Dispersion Characteristics ◽

Poly Methyl Methacrylate ◽

Dispersion Wavelength ◽

Zero Dispersion Wavelength

AbstractIn this paper, the dispersion characteristics of two standard single-mode optical fibers (SMFs), fabricated with silica and poly (methyl methacrylate) (PMMA) are studied in telecommunication spectral regions. The effect of structural parameters, such as the radius of the fiber core and the relative core-cladding index difference, is numerically investigated. It is found that over whole spectral range, the PMMA-based SMF shows lower dispersion than the silica SMF. Also, the zero-dispersion wavelength (ZDW) of PMMA-based SMF is longer than that of silica fiber. The results may be of practical importance for the telecommunication applications.

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Shaping Beam Profiles Using Plastic Optical Fiber Tapers with Application to Ice Sensors

Sensors ◽

10.3390/s20092503 ◽

2020 ◽

Vol 20 (9) ◽

pp. 2503

Author(s):

Kostas Amoiropoulos ◽

Georgia Kioselaki ◽

Nikolaos Kourkoumelis ◽

Aris Ikiades

Keyword(s):

Fiber Optics ◽

Optical Fibers ◽

Laser Cooling ◽

Detection Efficiency ◽

Numerical Aperture ◽

Beam Profile ◽

Hollow Beam ◽

Enhanced Sensitivity ◽

Surface Irregularities ◽

Plastic Optical Fibers

Using either bulk or fiber optics the profile of laser beams can be altered from Gaussian to top-hat or hollow beams allowing enhanced performance in applications like laser cooling, optical trapping, and fiber sensing. Here, we report a method based on multimode Plastic Optical Fibers (POF) long-tapers, to tweak the beam profile from near Gaussian to a hollow beam, by generating surface irregularities on the conical sections of the taper with a heat-and-pull technique. Furthermore, a cutback technique applied on long tapers expanded the output beam profile by more than twice the numerical aperture (NA) of the fiber. The enhanced sensitivity and detection efficiency of the extended profile was tested on a fiber optical ice sensor related to aviation safety.

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Fabrication of Lensed Plastic Optical Fiber Array Using Electrostatic Force

Journal of Manufacturing Science and Engineering ◽

10.1115/1.4004204 ◽

2011 ◽

Vol 133 (3) ◽

Cited By ~ 1

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.

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