Transmission of red-laser radiation by using Bragg fibers with air cores

0457525 - ÚFE 2016 RIV US eng C - Konferenční příspěvek (zahraniční konf.)
Matějec, Vlastimil - Podrazký, Ondřej - Kašík, Ivan - Frank, M. - Jelínek, M. - Kubeček, V.
Transmission of red-laser radiation by using Bragg fibers with air cores.
MICRO-STRUCTURED AND SPECIALTY OPTICAL FIBRES IV. Vol. 9507. Bellingham: SPIE, 2015 - (Kalli, K.; Kaňka, J.; Mendez, A.), 95070Q. Proceedings of SPIE. ISBN 978-1-62841-628-2. ISSN 0277-786X.
[Conference on Micro-Structured and Specialty Optical Fibres IV. Prague (CZ), 15.04.2015-16.04.2015]
Grant CEP: GA ČR GAP102/12/2361
Institucionální podpora: RVO:67985882
Klíčová slova: Laser power delivery * MCVD method * Bragg fiber
Kód oboru RIV: JA - Elektronika a optoelektronika, elektrotechnika

This paper presents experimental results on transmission characteristics of a Bragg fiber with an air core at a wavelength of 632 nm. The results are compared with those recently reported for the same fiber but at a wavelength of 1064 nm. The cladding of the fiber consists of three pairs of Bragg layers. Each pair is composed of one layer with a high and one layer with a low refractive index. A diameter of the air core is of about 50 mu m. A theoretical modelling of Bragg fibers was carried out from which band gap characteristics of the fiber cladding were determined for the refractive-index contrast of the high-and low-index layers on a level of 0.03 and wavelength of 632 nm and 1064 nm.
Preforms of the Bragg fiber in the form of tubes were prepared by the MCVD method. Germanium dioxide and phosphorous pentoxide were used as silica dopants for the high-index layers. The low-index layers were fabricated of silica slightly doped with phosphorous pentoxide. The last layer applied was the high-index one. Bragg fibers were drawn from the tubes under controlled temperatures around 2000 degrees C in order to obtain the fibers with designed dimensions of Bragg claddings and air cores. Results of characterization of prepared fibers with optical microscopy are presented in the paper. The transmittance and attenuation of the fibers at 632 nm were measured with a continuous-wave He-Ne laser as a light source. Spatial distributions of output beams from the fibers were also determined
Trvalý link: http://hdl.handle.net/11104/0257911