Laser Speckle Photography for the Measurement of Changes in Refractive Index in Phase Media

  • B. S. Ramprasad
  • T. S. Radha
  • E. S. R. Gopal
Conference paper


A technique of measurement of changes in refractive index in liquids and gases using laser speckle photography is presented. By analysing Young’s fringes from the double exposed specklegrams changes in refractive index of liquid mixtures as small as 0.0005 can be measured. The application of this technique for the nondestructive testing of incandescent lamps is described.


Refractive Index Liquid Mixture Speckle Pattern Incandescent Lamp Photographic Plate 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Es wird ein Verfahren für die Messung von Änderungen des Beugungsgrades in Flüssigkeiten und Gasen mit Hilfe der Laser-Speckle-Fotografie vorgestellt. Durch die Auswertung der Youngschen Interferenzstreifen auf den doppelbelichteten Specklegrammen lassen sich die kleinsten Änderungen des Beugungsgrades in flüssigen Gemischen bis zu 0,0005 messen. Die Anwendung dieses Verfahrens auf die zerstörungsfreie Prüfung von Glühlampen wird beschrieben.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Merzkirch, W.; Flow Visualization. New York, London: Academic Press 1974.Google Scholar
  2. 2.
    Jones, R. and Catherine Wykes.; Holographic and Speckle interferometry. Cambridge: Cambridge University Press 1983.Google Scholar
  3. 3.
    Köpf, V.; Application of speckling for measuring the deflection of laser light by phase objects. Opt.Comm. 5 (1972) 347.CrossRefGoogle Scholar
  4. 4.
    Farrel, P.V. and Hofeldt, D.L.; Temperature measurement in gases using speckle photography. Appl. Opt. 23 (1984) 1055–1059.CrossRefGoogle Scholar
  5. 5.
    Ramprasad, B.S.; Ph.D. Thesis. Indian Institute of Science, Bangalore 1987.Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1989

Authors and Affiliations

  • B. S. Ramprasad
    • 1
  • T. S. Radha
    • 1
  • E. S. R. Gopal
    • 1
  1. 1.Instrumentation and Services UnitIndian Institute of ScienceBangaloreIndia

Personalised recommendations