Mr. Adam S. Hokansson Profile

Adam S. Hokansson

Director of Fiber Value Stream at OFS Specialty Photonics Div.

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Publications (10)

Proceedings Article | 4 March 2022 Presentation + Paper

A new polyimide coating for optical fibers: demonstration of advantageous characteristics in harsh environments

Matthew Popelka, Andrei Stolov, Adam Hokansson, Jie Li, Michael Hines

Proceedings Volume 11997, 119970J (2022) https://doi.org/10.1117/12.2608322

KEYWORDS: Optical fibers, Coating, Glasses, Silica, Standards development, Signal attenuation, Resistance, Polymers, Metals, Liquids

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Proceedings Article | 27 February 2019 Presentation + Paper

Effects of e-beam and gamma sterilization on attenuation of selected single-mode and mutimode optical fibers

Andrei Stolov, Adam Hokansson, Jie Li, Man Yan, William Smith, Jaehan Kim

Proceedings Volume 10872, 108720B (2019) https://doi.org/10.1117/12.2504519

KEYWORDS: Optical fibers, Signal attenuation, Gamma radiation, Germanium, Coating, Aluminum, Multimode fibers, Radiation effects, Silica, Cladding

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Sterilization of medical equipment using e-beam or gamma radiation produces high sterility assurance but may lead to alterations in materials being treated. Thus, color centers developed in optical fibers result in added attenuation. In this work a series of specialty single-mode (SM) and multimode (MM) optical fibers (13 in total) were exposed to gamma and e-beam sterilization doses of 32 kGy, and the radiation-induced attenuation was investigated. The optical fibers selected for the study had different core chemical compositions, including pure silica and also SiO₂doped with Ge, F, P and Al. The fibers also differed in the clad diameters (80 and 125 μm), numerical aperture (0.1 – 0.21), coating types (carbon, acrylate, polyimide) and the cutoff wavelength (SM fibers only, 930 – 1470 nm). Effects of all these features on the radiation-induced attenuation were analyzed primarily in the framework of medical applications. The radiation-induced optical losses can be moderated by subsequent thermal treatment of the fibers, and such option was also investigated. Our results showed that while the radiation-induced losses may be high (10² – 10⁴ dB/km), sterilization using e-beam and gamma radiation can be acceptable for many medical applications that deploy 3 m or less fiber lengths. After gamma or e-beam sterilization, 3 meters length of SM fibers with pure SiO₂ and Ge doped core transmit >98% of optical power at 1550 and 1310 nm. In contrast, similar length of SM fibers with P and Al doped cores exhibit very low transmission and cannot be used after ionizing sterilization. Among the MM fiber, F-doped core fibers display much higher transmission than Ge-core fibers, especially at 850 nm. The clad diameter, coating type and bend insensitive features in the refractive index profile did not show much effect on the radiation-induced loss. While gamma and e-beam radiation caused similar changes in the attenuation spectra, gamma radiation caused ~25% higher loss increase than e-beam at the same 32 kGy dose. Since our data showed that postradiation annealing at 100°C for 24 hours results in only ~30% recovery of the radiation induced loss, it may not be practical to implement such annealing scheme for medical applications.

Proceedings Article | 2 June 2014 Paper

Bragg gratings in carbon coated optical fibers and their potential sensor applications in harsh environment

Yaowen Li, David Kudelko, Adam Hokansson, Debra Simoff, Andrei Stolov, Joanna Ng, Joel Mann

Proceedings Volume 9157, 91573X (2014) https://doi.org/10.1117/12.2059676

KEYWORDS: Carbon, Coating, Reflection, Fiber Bragg gratings, Optical fibers, Environmental sensing, Sensors, Fiber optics sensors, Hydrogen, Modulation

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Proceedings Article | 20 February 2014 Paper

Effects of sterilization on optical and mechanical reliability of specialty optical fibers and terminations

Andrei Stolov, Edward Warych, William Smith, Paula Fournier, Adam Hokansson, Jie Li, R. Steve Allen

Proceedings Volume 8938, 893806 (2014) https://doi.org/10.1117/12.2036864

KEYWORDS: Optical fibers, Ultraviolet radiation, Silicon, Optical coatings, Connectors, Signal attenuation, Cladding, Gamma radiation, Adhesives, Glasses

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Proceedings Article | 20 March 2013 Paper

Effects of sterilization methods on key properties of specialty optical fibers used in medical devices

Andrei Stolov, Brian Slyman, David Burgess, Adam Hokansson, Jie Li, R. Steve Allen

Proceedings Volume 8576, 857606 (2013) https://doi.org/10.1117/12.1000005

KEYWORDS: Optical fibers, Gamma radiation, Silicon, Polymers, Signal attenuation, Optical coatings, Cladding, Neodymium, Glasses, Oxides

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Proceedings Article | 28 February 2012 Paper

Optical fibers with polyimide coatings for medical applications

Andrei Stolov, Brian Slyman, Debra Simoff, Adam Hokansson, R. Steve Allen, John Earnhardt

Proceedings Volume 8215, 82150B (2012) https://doi.org/10.1117/12.916858

KEYWORDS: Optical fibers, Optical coatings, Neodymium, Corrosion, Glasses, Cladding, Silica, Humidity, Inspection, Microscopes

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Proceedings Article | 21 February 2009 Paper

Study of laser-induced damage to large core silica fiber by Nd:YAG and Alexandrite lasers

Xiaoguang Sun, Jie Li, Adam Hokansson, Dan Whelan, Michael Clancy

Proceedings Volume 7173, 71730E (2009) https://doi.org/10.1117/12.807758

KEYWORDS: Optical fibers, Fiber lasers, Alexandrite lasers, Polymers, Nd:YAG lasers, Glasses, Laser induced damage, Coating, Silica, Pulsed laser operation

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Proceedings Article | 15 February 2007 Paper

Study of optical fiber damage under tight bend with high optical power at 2140 nm

Xiaoguang Sun, Jie Li, Adam Hokansson

Proceedings Volume 6433, 643309 (2007) https://doi.org/10.1117/12.699202

KEYWORDS: Fiber lasers, Silica, Optical fibers, Coating, Cladding, Polymers, Laser induced damage, Laser applications, Laser energy, Glasses

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Proceedings Article | 10 January 2005 Paper

A low-loss specialty fiber designed for 980/1600 WDM coupler used in the L-band EDFA

Honggu Jiang, Adam Hokansson, Timothy McMahon, Jie Li

Proceedings Volume 5623, (2005) https://doi.org/10.1117/12.577166

KEYWORDS: Signal attenuation, L band, Wavelength division multiplexing, Fiber couplers, Optical amplifiers, Single mode fibers, Fusion splicing, Specialty optical fibers, Erbium, Waveguides

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Proceedings Article | 10 September 2004 Paper

Aging behavior of optical fibers in aqueous environments

Eric Lindholm, Jie Li, Adam Hokansson, Brian Slyman, David Burgess

Proceedings Volume 5465, (2004) https://doi.org/10.1117/12.544879

KEYWORDS: Silicon, Optical coatings, Optical fibers, Silica, Glasses, Carbon, Silicon carbide, Reliability, Interfaces, Fiber coatings

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Showing 5 of 10 publications

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