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LUND UNIVERSITY LIBRARIES

Intensity distribution conversion from Gaussian to Top-Hat in a single-mode fiber connector

Willstrand, Ola LU (2013) In Lund Reports on Atomic Physics PHYM01 20122
Atomic Physics
Abstract
Gaussian to top-hat beam shaping is widely used today in areas of cutting, welding, and laser patterning. Typically, single-mode solid state lasers are used whose Gaussian intensity distribution is transformed into a top-hat. In this thesis the transformation is applied in a single-mode fiber connector, where the aim is a uniform intensity distribution of the emerging light from the connector. This is desirable in unclean environments where the probability of dirt or dust particles on the connector interface is high. Different methods of the transformation are analyzed, and the circular symmetric Powell lens is found most suited for implementation in a fiber connector. Two different connector-models where the Powell lens is involved are... (More)
Gaussian to top-hat beam shaping is widely used today in areas of cutting, welding, and laser patterning. Typically, single-mode solid state lasers are used whose Gaussian intensity distribution is transformed into a top-hat. In this thesis the transformation is applied in a single-mode fiber connector, where the aim is a uniform intensity distribution of the emerging light from the connector. This is desirable in unclean environments where the probability of dirt or dust particles on the connector interface is high. Different methods of the transformation are analyzed, and the circular symmetric Powell lens is found most suited for implementation in a fiber connector. Two different connector-models where the Powell lens is involved are designed and for this purpose two optical simulation software products, FRED and ZEMAX, are used. These two products are compared concerning user friendliness, support, optimization feature, and accuracy of the simulations. The comparison is valid for the content of this thesis, but the scope of applications of these products reach far beyond this project. Because of the expensiveness in producing just one custom made lens, such as the circular symmetric Powell lens, instead cylindrical Powell lenses were used in the experiments, which are catalogue lenses. The experiments showed i.a. that the transformation predicted was successful. They also revealed some shortcomings in the simulation tools. (Less)
Please use this url to cite or link to this publication:
author
Willstrand, Ola LU
supervisor
organization
course
PHYM01 20122
year
type
H2 - Master's Degree (Two Years)
subject
keywords
Gaussian beam, top-hat, fiber connector, Powell lens, FRED, ZEMAX
publication/series
Lund Reports on Atomic Physics
report number
LRAP-471
language
English
id
3410933
date added to LUP
2013-02-06 21:30:18
date last changed
2013-02-06 21:30:18
@misc{3410933,
  abstract     = {Gaussian to top-hat beam shaping is widely used today in areas of cutting, welding, and laser patterning. Typically, single-mode solid state lasers are used whose Gaussian intensity distribution is transformed into a top-hat. In this thesis the transformation is applied in a single-mode fiber connector, where the aim is a uniform intensity distribution of the emerging light from the connector. This is desirable in unclean environments where the probability of dirt or dust particles on the connector interface is high. Different methods of the transformation are analyzed, and the circular symmetric Powell lens is found most suited for implementation in a fiber connector. Two different connector-models where the Powell lens is involved are designed and for this purpose two optical simulation software products, FRED and ZEMAX, are used. These two products are compared concerning user friendliness, support, optimization feature, and accuracy of the simulations. The comparison is valid for the content of this thesis, but the scope of applications of these products reach far beyond this project. Because of the expensiveness in producing just one custom made lens, such as the circular symmetric Powell lens, instead cylindrical Powell lenses were used in the experiments, which are catalogue lenses. The experiments showed i.a. that the transformation predicted was successful. They also revealed some shortcomings in the simulation tools.},
  author       = {Willstrand, Ola},
  keyword      = {Gaussian beam,top-hat,fiber connector,Powell lens,FRED,ZEMAX},
  language     = {eng},
  note         = {Student Paper},
  series       = {Lund Reports on Atomic Physics},
  title        = {Intensity distribution conversion from Gaussian to Top-Hat in a single-mode fiber connector},
  year         = {2013},
}