OSA's Digital Library

Applied Optics

Applied Optics


  • Vol. 39, Iss. 36 — Dec. 20, 2000
  • pp: 6754–6760

Beam quality after propagation of Nd:YAG laser light through large-core optical fibers

Andreas Kuhn, Ian J. Blewett, Duncan P. Hand, and Julian D. C. Jones  »View Author Affiliations

Applied Optics, Vol. 39, Issue 36, pp. 6754-6760 (2000)

View Full Text Article

Enhanced HTML    Acrobat PDF (106 KB)

Browse Journals / Lookup Meetings

Browse by Journal and Year


Lookup Conference Papers

Close Browse Journals / Lookup Meetings

Article Tools



Laser beam characteristics are altered during propagation through large-core optical fibers. The distribution of modes excited by the input laser beam is modified by means of mode coupling on transmission through the fiber, leading to spatial dispersion of the profile and, ultimately and unavoidably, to degradation in the quality of the delivered beam unless the beam is spatially filtered with consequent power loss. Furthermore, a mismatch between the intensity profile of a typical focused high-power laser beam and the profile of the step-index fiber gives rise to additional beam-quality degradation. Modern materials processing applications demand ever higher delivered beam qualities (as measured by a parameter such as M2) to achieve greater machining precision and efficiency, a demand that is currently in conflict with the desire to utilize the convenience and flexibility of large-core fiber-optic beam delivery. We present a detailed experimental investigation of the principal beam-quality degradation effects associated with fiber-optic beam delivery and use numerical modeling to aid an initial discussion of the causes of such degradation.

© 2000 Optical Society of America

OCIS Codes
(000.4430) General : Numerical approximation and analysis
(060.2270) Fiber optics and optical communications : Fiber characterization
(060.2300) Fiber optics and optical communications : Fiber measurements
(140.3390) Lasers and laser optics : Laser materials processing
(140.3530) Lasers and laser optics : Lasers, neodymium

Original Manuscript: November 2, 1999
Revised Manuscript: August 28, 2000
Published: December 20, 2000

Andreas Kuhn, Ian J. Blewett, Duncan P. Hand, and Julian D. C. Jones, "Beam quality after propagation of Nd:YAG laser light through large-core optical fibers," Appl. Opt. 39, 6754-6760 (2000)

Sort:  Author  |  Year  |  Journal  |  Reset  


  1. N. Reng, T. Beck, M. Ostermeyer, “Comparison of different types of fibers for high power cw Nd:YAG lasers,” in High-Power Gas and Solid State Lasers, M. Bohrer, T. Letardi, D. Schuoecker, H. Weber, eds., Proc SPIE2206, 443–454 (1994).
  2. B. V. Hunter, K. H. Leong, C. B. Miller, J. F. Golden, R. D. Glesias, P. J. Laverty, “Selecting a high-power fiber-optic laser beam delivery system,” in Proceedings of ICALEO’96 (Laser Institute of America, Orlando, Fla., 1996), pp. 173–182.
  3. M. W. Sasnett, “Propagation of multimode laser beams—the M2 factor,” in The Physics and Technology of Laser Resonators, D. R. Hall, P. E. Jackson, eds. (Hilger, Bristol, UK, 1989).
  4. T. Beck, I. G. Bostanjoglo, N. Kugler, K. Richter, H. Weber, “Laser beam drilling applications in novel materials for the aircraft industry,” in Proceedings of ICALEO’97 (Laser Institute of America, Orlando, Fla., 1997), pp. E93–E102.
  5. A. Kuhn, P. French, D. P. Hand, I. J. Blewett, M. Richmond, J. D. C. Jones, “Fibre optic delivery of high beam quality, high energy Nd:YAG pulses for percussion drilling,” in Proceedings of ICALEO’98 (Laser Institute of America, Orlando, Fla., 1998), Vol. 85, Section B-40.
  6. D. P. Hand, J. D. C. Jones, “Single-mode fiber delivery of Nd:YAG light for precision machining applications,” Appl. Opt. 37, 1602–1606 (1998). [CrossRef]
  7. D. Gloge, “Propagation effects in optical fibres,” IEEE Trans. Microwave Theory Tech. 23, 106–120 (1975). [CrossRef]
  8. D. Marcuse, Light Transmission Optics (Van Norstrand Reinhold, New York, 1982).
  9. D. Gloge, “Optical power flow in multimode fibers,” Bell Syst. Tech. J. 51, 1767–1783 (1972). [CrossRef]
  10. J. Saijonmaa, D. Yevik, “Beam-propagation analysis of loss in bent optical waveguides and fibers,” J. Opt. Soc. Am. 73, 1785–1791 (1983). [CrossRef]
  11. L. B. Felsen, “Rays, modes and beams in optical fibre waveguides,” Opt. Quantum Electron. 9, 189–195 (1977). [CrossRef]
  12. W. A. E. Goethals, “Laser beam analysis by geometrical optics,” in The Physics and Technology of Laser Resonators, D. R. Hall, P. E. Jackson, eds. (Hilger, Bristol, UK, 1989).
  13. A. Yariv, Optical Electronics, 3rd ed. (Holt-Saunders, New York, 1985).
  14. D. Su, A. A. P. Boechat, J. D. C. Jones, “Curvature induced mode coupling in large core optical fibres with step refractive index profiles,” Opt. Lasers Eng. 20, 193–205 (1994).

Cited By

Alert me when this paper is cited

OSA is able to provide readers links to articles that cite this paper by participating in CrossRef's Cited-By Linking service. CrossRef includes content from more than 3000 publishers and societies. In addition to listing OSA journal articles that cite this paper, citing articles from other participating publishers will also be listed.

« Previous Article  |  Next Article »

OSA is a member of CrossRef.

CrossCheck Deposited