Title page for etd-0802111-220522


[Back to Results | New Search]

URN etd-0802111-220522
Author Li-Jin Wang
Author's Email Address No Public.
Statistics This thesis had been viewed 5355 times. Download 1869 times.
Department Electro-Optical Engineering
Year 2010
Semester 2
Degree Master
Type of Document
Language zh-TW.Big5 Chinese
Title Effect of Curvature Radius and Offset on Coupling Efficiency in Double-Variable-Curvature Fiber Microlens
Date of Defense 2011-06-24
Page Count 89
Keyword
  • coupling
  • double-variable-curvature
  • fiber microlens
  • Abstract A study of double-variable-curvature microlenses (DVCM) for promoting coupling efficiency between the high-power 980-nm pumping laser diodes and the single-mode fibers has been proposed. In comparison with the previous works on asymmetric fiber microlenses fabricated by the multi-step processes with complicated fabrication, the advantages of the DVCM structure for achieving high coupling are a single-step fabrication, a reproducible process, and a high-yield output. In the fusing procedure, the slight arc fusion was mainly applied for fine polishing merely instead of reshaping for the reason that the fabricated double-variable-curvature fiber endface (DVCFE) was very close to the ideal shape. Hence, the fabrication time was reduced and the yield was promoted due to the withdrawn step of tip elimination.
    In this study, the geometric center of the fiber was defined through, the cladding diameter and the core diameter, for comparison to measure the offset. The offset measured by the core diameter was more accurate and coincidence with the coupling efficiency in the experiment.
    In the fabricated 45 DVCMs, to achieve the average coupling efficiencies higher than 84%, the offsets were ought to be controlled in merely less than 0.6μm with the curvature radii in the minor axis ranged from 2.4 to 2.9μm (with tolerance of 0.5μm). Alternatively, the offsets were ought to be controlled in less than 0.3μm though the curvature radii in the minor axis ranged from 2.4 to 3.7μm (with larger tolerance of 1.3μm). However, it was more difficult to control over the offsets than the curvature radii in the minor axis while fabricating the DVCMs.
    In conclusion, to achieve higher yield, it was relatively practical to control the offsets of fiber microlenses to be less than 0.6μm with 2.4 to 2.9μm curvature radius. As a result, the coupling efficiencies were all higher than 80%.
    Advisory Committee
  • Ching-Ting Lee - chair
  • Maw-Tyan Sheen - co-chair
  • Ying-Chien Tsai - co-chair
  • Yi-Cheng Hsu - co-chair
  • Wood-Hi Cheng - advisor
  • Files
  • etd-0802111-220522.pdf
  • Indicate in-campus at 1 year and off-campus access at 1 year.
    Date of Submission 2011-08-02

    [Back to Results | New Search]


    Browse | Search All Available ETDs

    If you have more questions or technical problems, please contact eThesys