Abstract

Scattering from an apparently perfect fiber, placed perpendicular to a laser beam, produces an out of plane scattering pattern containing an internal structure not predicted by simple fiber scattering theory. A photographic study of light scattered from twisted fibers shows that the effect is due to periodic disturbances along the fiber axis that act as coherent scattering centers.

© 1980 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |

  1. E. Hecht, A. Zajac, Optics (Addison-Wesley, Reading, Mass., 1974); F. A. Jenkins, H. E. White, Fundamental of Optics (McGraw-Hill, New York, 1957); R. S. Longhurst, Geometrical and Physical Optics (Wiley, New York, 1967).
  2. C. Bohren, Dept. Meteorology, Pennsylvania State U., private communication.
  3. H. C. Van de Hulst, Light Scattering by Small Particles (Wiley, New York, 1957).
  4. M. Kerker, The Scattering of Light and Other Electromagnetic Radiation (Academic, New York, 1969).

Bohren, C.

C. Bohren, Dept. Meteorology, Pennsylvania State U., private communication.

Hecht, E.

E. Hecht, A. Zajac, Optics (Addison-Wesley, Reading, Mass., 1974); F. A. Jenkins, H. E. White, Fundamental of Optics (McGraw-Hill, New York, 1957); R. S. Longhurst, Geometrical and Physical Optics (Wiley, New York, 1967).

Kerker, M.

M. Kerker, The Scattering of Light and Other Electromagnetic Radiation (Academic, New York, 1969).

Van de Hulst, H. C.

H. C. Van de Hulst, Light Scattering by Small Particles (Wiley, New York, 1957).

Zajac, A.

E. Hecht, A. Zajac, Optics (Addison-Wesley, Reading, Mass., 1974); F. A. Jenkins, H. E. White, Fundamental of Optics (McGraw-Hill, New York, 1957); R. S. Longhurst, Geometrical and Physical Optics (Wiley, New York, 1967).

Other

E. Hecht, A. Zajac, Optics (Addison-Wesley, Reading, Mass., 1974); F. A. Jenkins, H. E. White, Fundamental of Optics (McGraw-Hill, New York, 1957); R. S. Longhurst, Geometrical and Physical Optics (Wiley, New York, 1967).

C. Bohren, Dept. Meteorology, Pennsylvania State U., private communication.

H. C. Van de Hulst, Light Scattering by Small Particles (Wiley, New York, 1957).

M. Kerker, The Scattering of Light and Other Electromagnetic Radiation (Academic, New York, 1969).

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (7)

Fig. 1
Fig. 1

Geometrical relationship between a laser beam, some scattering obstacles, and their diffraction patterns: (A) single fiber perpendicular to laser beam scatters light through angle θ; (B) single fiber perpendicular to laser beam tilted through angle ϕ scatters light through angle θ forming diffraction pattern tilted through angle ϕ; (C) single fiber tilted through angle β toward screen; various β tilts create various conic sections on screen; (D) rectangular aperture perpendicular to laser beam scatters light in both the θ and ϕ directions.

Fig. 2
Fig. 2

The I(θ) scattering from an apparently perfect cylindrical quartz fiber showing light scattered above and below the β = 0 axis.

Fig. 3
Fig. 3

Experimental apparatus used to photograph the scattering patterns. Laser light scattered by the fiber hits the screen at point P located at (x,y) or (θ,β). A motor twists the fiber to create the desired number of segments per length.

Fig. 4
Fig. 4

Micrographs of two different twisted fibers of elliptical cross section, one containing four times as many twists per length.

Fig. 5
Fig. 5

Photographs of the fiber scattering patterns as a function of the number of segments per millimeter indicated at the center of each diffraction pattern. The top middle pattern is from an untwisted fiber. Patterns on the left have a cat’s whisker appearance, on the right a herringbone appearance. Midway between the cat’s whisker and herringbone appearances, the diffraction pattern is nonsymmetric about β (middle column). As the number of segments per millimeter increases, the herringbone and cat’s whisker patterns become indistinguishable and develop into a general rectangular diffraction pattern.

Fig. 6
Fig. 6

Geometry showing the origin of β scattering from a twisted fiber.

Fig. 7
Fig. 7

Fiber-beam geometry showing the origin of symmetric and nonsymmetric scattering patterns.

Equations (1)

Equations on this page are rendered with MathJax. Learn more.

I ( θ ) = I 0 [ sin ( π w λ sin θ ) π w λ sin θ ] 2 ,

Metrics