Optical properties of Yb-doped fibers prepared by gas phase doping

Lindner, Florian; Aichele, Claudia; Schwuchwo, A.; Leich, Martin; Scheffel, A.; Unger, Sonja

doi:10.1117/12.2036928

Cited by 14 publications

(17 citation statements)

References 21 publications

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“…4 presents the NA of active fibers which is in the range of 0.08-0.2 while the dotted curve is the predicted trend of NA due to pure Al 2 O 3 doping with identical AlCl 3 flow rates as in active fibers. It also has been observed that Al 2 O 3 concentration in active fibers decreases with increment of Yb content as compared to passive fibers which is similar in nature as reported by Lindner et al [18]. Fig.…”

Section: ) Carrier Gas Flow Ratesupporting

confidence: 86%

“…Influence of numbers of core layer passes on core diameter. limited to 5-6 cm at maximum as compared to the long taper range of ∼20 cm as observed and reported by Lindner et al [18].…”

Section: ) Number Of Deposition Passessupporting

confidence: 79%

“…As described in the earlier reported results, this process suffers from poor repeatability [12], [22], "clogged" delivery lines due to condensation of precursor materials [22], [23], shorter usable preform length [13], [14], lower RE concentrations [12], [13], non-uniform RE distribution along the length of the preform [15] and higher OH − content in the fibers [11], [18]. So, the prime target of this study was to demonstrate a standardized process technology to fabricate LC, low numerical aperture (NA) and high Yb-doped fibers for laser applications with higher reproducibility.…”

Section: A Optimization Of the Process Parametersmentioning

confidence: 92%

“…A number of methods were followed to incorporate Yb +3 ions into silica glass, most of which are alterations of the conventional modified chemical vapor deposition (MCVD) process. Two of the most common techniques are solution doping method [9], [10] and vapor phase doping technique [11]- [18]. Till date, solution doping method is the most popular due to its simple operational scheme and wide range of selectivity of dopants.…”

Section: Introductionmentioning

confidence: 99%

“…In addition, since the incorporation of REs and co-dopands occurs simultaneously with the deposition of silica, there is the possibility for homogeneous dopants distribution in the silica network which leads to significantly less RE clustering. However, till date, very few fibers are made by this method [11]- [18] due to many critical challenges of the process, viz. decomposition of RE compounds prior to the reaction zone, blocking of delivery lines due to condensation of precursor materials [22], [23], variation in dopants concentration over the length of the preforms [15], [22] etc.…”

Section: Introductionmentioning

confidence: 99%

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An Optimized Vapor Phase Doping Process to Fabricate Large Core Yb-Doped Fibers

Saha

Pal

et al. 2015

J. Lightwave Technol.

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The paper demonstrates a standardized process of vapor phase doping to fabricate large core Yb-doped preforms with longer useful length in reproducible manner. The optimization of the process led to successful achievement of Yb-doped core thickness of 4.5 mm (in 14.8 mm of preform diameter) by depositing up to 30 number of core layers with controlled amount of generated precursor vapors. The influence of the process parameters was studied rigorously to enhance the useful preform length up to 380 mm. A combination of Yb and Al in different proportions was doped into the core with uniform dopant concentration along the length by adjusting few process parameters efficiently. The Al 2 O 3 concentration up to the level of 17.8 mol% has been achieved successfully which resulted in NA of 0.31. This is the highest ever doping of Al in passive fibers by any modified chemical vapor deposition process. The Yb 2 O 3 content in the active fibers is as high as 0.47 mol%.

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Section: ) Carrier Gas Flow Ratesupporting

confidence: 86%

“…Influence of numbers of core layer passes on core diameter. limited to 5-6 cm at maximum as compared to the long taper range of ∼20 cm as observed and reported by Lindner et al [18].…”

Section: ) Number Of Deposition Passessupporting

confidence: 79%

Section: A Optimization Of the Process Parametersmentioning

confidence: 92%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

An Optimized Vapor Phase Doping Process to Fabricate Large Core Yb-Doped Fibers

Saha

Pal

et al. 2015

J. Lightwave Technol.

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Vapor phase doping process for fabrication of rare earth doped optical fibers: Current status and future opportunities

Saha

Sen

2016

Physica Status Solidi (a)

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Emerging application of rare-earth (RE) doped optical fibers in high power lasers requires preforms with stringent geometrical and optical properties. This in turn demands more versatile and reliable process technology which brought Vapor Phase Doping (VPD) into prominence. This technology has immense potential to overcome fiber fabrication related challenges viz, dopant-rich phase separation, RE uniformity in radial as well as longitudinal direction, "star-like" defect elimination from core-clad boundary and refractive index (RI) adjustment which results in improved beam quality and power stability of fiber laser. Further, high power lasers demand LMA active fibers with large core diameter and low numerical aperture (NA) which is easily producible by VPD method as it permits deposition of multiple RE doped core layers in a reproducible "in situ" manner. So, the prime focus is to optimize process technology to produce low RI, large core fibers. This article gives an overview of the comprehensive effort made by the global researchers to overcome challenges of VPD method and to demonstrate a standardized process technology for RE doping in silica glass preform.

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