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Pramana

, Volume 65, Issue 3, pp 413–424 | Cite as

Scattering of light by a periodic structure in the presence of randomness IV. Limit of detection by curve fitting

  • S. Chatterjee
  • V. C. Vani
Article

Abstract

In the context of scattering of light, we determine the extent of randomness within which a hidden periodic part can still be detected. The detection is carried out using a technique called the extended matched filtering, first introduced by us in this context. The earlier prediction, before our technique was introduced, had placed the limit of detection, by intensity measurements alone, at (r 0/Λ) ∼ 0.33, where r0 is the coherence length of light for scattering by the rough part of the surface and Λ is the wavelength of the periodic part of the surface. In our earlier works we have shown that by intensity measurements alone, the limit of detection can be taken to a much lower value of (r 0/Λ), when the extended matched filtering method is employed. In this paper we follow the extended matched filtering method, and try to reach the lowest possible value of detection in (r 0/Λ) by fitting the data to a polynomial. It is concluded by our numerical work that the lowest possible limit for detection from intensity measurements alone is (r 0/Λ) = 0.11.

Keywords

Light scattering matched filter curve fit 

PACS Nos

42.25.Fx 42.30.Kq 42.30.Sy 

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References

  1. [1]
    J C Dainty and D Newman,Opt. Lett. 8, 608 (1983)ADSCrossRefGoogle Scholar
  2. [2]
    H P Baltes, H A Ferwerda, A S Glass and B Steinle,Opt. Acta 28, 11 (1981)Google Scholar
  3. [3]
    S Chatterjee,Indian J. Phys. B74, 363 (2000)Google Scholar
  4. [4]
    S Chatterjee and V C Vani,Bull. Astr. Soc. India 30, 835 (2002)Google Scholar
  5. [5]
    S Chatterjee and V C Vani,J. Mod. Opt. 50, 833 (2003)zbMATHADSGoogle Scholar
  6. [6]
    V C Vani and S Chatterjee,Bull. Astr. Soc. India 31, 457 (2003)ADSGoogle Scholar
  7. [7]
    V C Vani and S Chatterjee,Curr. Sci. 86, 177 (2004)Google Scholar
  8. [8]
    V C Vani and S Chatterjee,Appl. Opt. 46, 3664 (2004)CrossRefADSGoogle Scholar
  9. [9]
    P Beckmann and A Spizzichino,The scattering of electromagnetic waves from random surfaces (Pergamon Press, London, 1963)Google Scholar
  10. [10]
    P Beckmann, Scattering of light by rough surfaces, inProgress in optics edited by E Wolf (North Holland, 1967) Vol. 6, pp. 55–69Google Scholar
  11. [11]
    P R BevingtonData reduction and error analysis for the physical sciences (McGraw Hill, New York, 1969)Google Scholar

Copyright information

© Indian Academy of Sciences 2005

Authors and Affiliations

  • S. Chatterjee
    • 1
  • V. C. Vani
    • 2
  1. 1.Indian Institute of AstrophysicsBangaloreIndia
  2. 2.Department of InstrumentationIndian Institute of ScienceBangaloreIndia

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