Experimental Investigation and Characterization of Fabrication Shaped Clad Optical Fiber by Thermally Polishing Optical Fiber Preforms with CO2 Laser

0518811 - ÚFE 2020 RIV US eng C - Conference Paper (international conference)
Jasim, Ali - Podrazký, Ondřej - Peterka, Pavel - Todorov, Filip - Honzátko, Pavel
Experimental Investigation and Characterization of Fabrication Shaped Clad Optical Fiber by Thermally Polishing Optical Fiber Preforms with CO2 Laser.
Proc. of SPIE, Micro-structured and Specialty Optical Fibres VI. Vol. 11029. Bellingham: SPIE, 2019 - (Kalli, K.; Mendez, A.; Peterka, P.), č. článku 1102909. ISBN 978-1-5106-2725-3. ISSN 0277-786X. E-ISSN 1996-756X.
[Conference on Micro-Structured and Specialty Optical Fibres VI. Praha (CZ), 03.04.2019-04.04.2019]
R&D Projects: GA ČR(CZ) GA19-03141S
Institutional support: RVO:67985882
Keywords : Double clad fiber * High-power fiber lasers * Non-circular optical fiber * Optical fiber drawing * Optical preform shaping
OECD category: Optics (including laser optics and quantum optics)

We experimentally investigated loss of multimode optical fibers (MMFs) drawn of thermally shaped optical fiber preforms (OFPs). Such preforms are typically used for fabrication of double clad active fibers. The investigation involved undoped shaped MMFs coated with a low refractive index polymer. The fibers were drawn of silica rod, prepared by collapsing a pure silica tube (Heraeus F300, OH content is 0.2 ppm) in the MCVD lathe. Background losses of undoped MMFs with inner cladding of various geometries shaped by CO2 laser were measured via cut-back method. Losses of the shaped MMFs were compared to the loss of the circular and of the mechanically shaped MMF. Constraints, drawbacks and advantages of shaping the fiber preform using the CO2 laser are discussed. Shaping OFPs with CO2 beam provides advantages of quick polishing, smooth surface, and freeform shape. Results show that mechanical polishing technique leads to significant OH content elimination, which is expressed as reduced absorption peaks at wavelengths of 0.945 mu m and 1.24 mu m, which correspond to the third and second overtone, respectively. The average perimeter length of fibers cross section governs absorption at polymer-glass interface
Permanent Link: http://hdl.handle.net/11104/0303861