Abstract

In the rainbow schlieren apparatus, a continuously graded rainbow filter is placed in the back focal plane of the decollimating lens. Refractive-index gradients in the test section thus appear as gradations in hue rather than irradiance. A simple system is described wherein a conventional color CCD array and video digitizer are used to quantify accurately the color attributes of the resulting image, and hence the associated ray deflections. The present system provides a sensitivity comparable with that of conventional interferometry, while being simpler to implement and less sensitive to mechanical misalignment.

© 1995 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. H. Schardin, “Schlieren methods and their applications,” NASA Rep. TT-F-12731 (NASA, Greenbelt, Md.; 1970) [Ergeb. Exakten Naturwiss. 20, 303 (1942)].
  2. W. Merzkirch, Flow Visualization (Academic, New York, 1974), pp. 71–102.
  3. G. S. Settles, “Color schlieren optics—a review of techniques and applications,” in Flow Visualization, W. Merzkirch, ed. (Hemisphere, New York, 1982), Vol. 2, pp. 749–759.
  4. W. L. Howes, “Rainbow schlieren and its applications,” Appl. Opt. 23, 2449–2460 (1984).
    [CrossRef] [PubMed]
  5. L. A. Vasil'ev, Schlieren Methods (Israel Program Scientific Trans., New York, 1971), pp. 10–11.
  6. C. M. Vest, “Interferometry of strongly refracting axisymmetric phase objects,” Appl. Opt. 14, 1601–1606 (1974).
    [CrossRef]
  7. E. E. Anderson, W. H. Stevenson, R. Viskanta, “Estimating the refractive error in optical measurements of transport phenomena,” Appl. Opt. 14, 185–188 (1974).
  8. C. M. Vest, Holographic Interferometry (Wiley, New York, 1979).
  9. J. Rheinberg, “On an addition to the methods of microscopical research, by a new way optically producing color-contrast between an object and its background, or between definite parts of the object itself,” J. R. Microsc. Soc. 16, 373–388 (1896).
    [CrossRef]
  10. J. R. Meyer-Arendt, H. Appelt, “Microscopic color schlieren system using a wedge interference filter,” Appl. Opt. 15, 2017–2019 (1976).
    [CrossRef] [PubMed]
  11. W. L. Howes, D. R. Buchele, “Optical interferometry of inhomogeneous gases,” J. Opt. Soc. Am. 56, 1517–1528 (1966).
    [CrossRef]
  12. R. N. Strickland, C. Kim, W. F. McDonnell, “Luminance, hue, and saturation processing of digital color images,” in Applications of Digital Image Processing IX, A. G. Tescher, ed., Proc. Soc. Photo-Opt. Instrum. Eng.697, 286–292 (1986).
    [CrossRef]
  13. R. C. Gonzalez, P. Wintz, Digital Image Processing (Addison-WesleyReading, Mass., 1977), p. 177.
  14. A. Pebler, J. M. Zomp, “Stabilizing the radiant flux of a xenon arc lamp,” Appl. Opt. 20, 4059–4061 (1981).
    [CrossRef] [PubMed]
  15. R. Roberts, “Cermax small fiber illuminating lamp LSX 130,” Engineering Note 183 (ILC Technology Inc., Sunnyvale, Calif., 1988).
  16. D. W. Holder, R. J. North, Schlieren Methods (Her Majesty's Stationery Office, London, 1963).
  17. D. R. Buchele, D. W. Griffin, “Compact color schlieren optical system,” Appl. Opt. 32, 4218–4222 (1993).
    [CrossRef] [PubMed]
  18. W. L. Howes, “Rainbow schlieren vs Mach–Zehnder interferometer: a comparison,” Appl. Opt. 24, 816–822 (1985).
    [CrossRef] [PubMed]
  19. B. Ovryn, E. M. Haake, “Temporal averaging of phase measurements in the presence of spurious phase drift: application to phase-stepped real-time holographic interferometry” Appl. Opt. 32, 147–154 (1993).
    [CrossRef] [PubMed]
  20. R. Dändliker, R. Thalmann, “Heterodyne and quasi-heterodyne holographic interferometry,” Opt. Eng. 24, 824– 826 (1980).

1993 (2)

1985 (1)

1984 (1)

1981 (1)

1980 (1)

R. Dändliker, R. Thalmann, “Heterodyne and quasi-heterodyne holographic interferometry,” Opt. Eng. 24, 824– 826 (1980).

1976 (1)

1974 (2)

1966 (1)

1896 (1)

J. Rheinberg, “On an addition to the methods of microscopical research, by a new way optically producing color-contrast between an object and its background, or between definite parts of the object itself,” J. R. Microsc. Soc. 16, 373–388 (1896).
[CrossRef]

Anderson, E. E.

Appelt, H.

Buchele, D. R.

Dändliker, R.

R. Dändliker, R. Thalmann, “Heterodyne and quasi-heterodyne holographic interferometry,” Opt. Eng. 24, 824– 826 (1980).

Gonzalez, R. C.

R. C. Gonzalez, P. Wintz, Digital Image Processing (Addison-WesleyReading, Mass., 1977), p. 177.

Griffin, D. W.

Haake, E. M.

Holder, D. W.

D. W. Holder, R. J. North, Schlieren Methods (Her Majesty's Stationery Office, London, 1963).

Howes, W. L.

Kim, C.

R. N. Strickland, C. Kim, W. F. McDonnell, “Luminance, hue, and saturation processing of digital color images,” in Applications of Digital Image Processing IX, A. G. Tescher, ed., Proc. Soc. Photo-Opt. Instrum. Eng.697, 286–292 (1986).
[CrossRef]

McDonnell, W. F.

R. N. Strickland, C. Kim, W. F. McDonnell, “Luminance, hue, and saturation processing of digital color images,” in Applications of Digital Image Processing IX, A. G. Tescher, ed., Proc. Soc. Photo-Opt. Instrum. Eng.697, 286–292 (1986).
[CrossRef]

Merzkirch, W.

W. Merzkirch, Flow Visualization (Academic, New York, 1974), pp. 71–102.

Meyer-Arendt, J. R.

North, R. J.

D. W. Holder, R. J. North, Schlieren Methods (Her Majesty's Stationery Office, London, 1963).

Ovryn, B.

Pebler, A.

Rheinberg, J.

J. Rheinberg, “On an addition to the methods of microscopical research, by a new way optically producing color-contrast between an object and its background, or between definite parts of the object itself,” J. R. Microsc. Soc. 16, 373–388 (1896).
[CrossRef]

Roberts, R.

R. Roberts, “Cermax small fiber illuminating lamp LSX 130,” Engineering Note 183 (ILC Technology Inc., Sunnyvale, Calif., 1988).

Schardin, H.

H. Schardin, “Schlieren methods and their applications,” NASA Rep. TT-F-12731 (NASA, Greenbelt, Md.; 1970) [Ergeb. Exakten Naturwiss. 20, 303 (1942)].

Settles, G. S.

G. S. Settles, “Color schlieren optics—a review of techniques and applications,” in Flow Visualization, W. Merzkirch, ed. (Hemisphere, New York, 1982), Vol. 2, pp. 749–759.

Stevenson, W. H.

Strickland, R. N.

R. N. Strickland, C. Kim, W. F. McDonnell, “Luminance, hue, and saturation processing of digital color images,” in Applications of Digital Image Processing IX, A. G. Tescher, ed., Proc. Soc. Photo-Opt. Instrum. Eng.697, 286–292 (1986).
[CrossRef]

Thalmann, R.

R. Dändliker, R. Thalmann, “Heterodyne and quasi-heterodyne holographic interferometry,” Opt. Eng. 24, 824– 826 (1980).

Vasil'ev, L. A.

L. A. Vasil'ev, Schlieren Methods (Israel Program Scientific Trans., New York, 1971), pp. 10–11.

Vest, C. M.

Viskanta, R.

Wintz, P.

R. C. Gonzalez, P. Wintz, Digital Image Processing (Addison-WesleyReading, Mass., 1977), p. 177.

Zomp, J. M.

Appl. Opt. (8)

J. Opt. Soc. Am. (1)

J. R. Microsc. Soc. (1)

J. Rheinberg, “On an addition to the methods of microscopical research, by a new way optically producing color-contrast between an object and its background, or between definite parts of the object itself,” J. R. Microsc. Soc. 16, 373–388 (1896).
[CrossRef]

Opt. Eng. (1)

R. Dändliker, R. Thalmann, “Heterodyne and quasi-heterodyne holographic interferometry,” Opt. Eng. 24, 824– 826 (1980).

Other (9)

R. Roberts, “Cermax small fiber illuminating lamp LSX 130,” Engineering Note 183 (ILC Technology Inc., Sunnyvale, Calif., 1988).

D. W. Holder, R. J. North, Schlieren Methods (Her Majesty's Stationery Office, London, 1963).

C. M. Vest, Holographic Interferometry (Wiley, New York, 1979).

R. N. Strickland, C. Kim, W. F. McDonnell, “Luminance, hue, and saturation processing of digital color images,” in Applications of Digital Image Processing IX, A. G. Tescher, ed., Proc. Soc. Photo-Opt. Instrum. Eng.697, 286–292 (1986).
[CrossRef]

R. C. Gonzalez, P. Wintz, Digital Image Processing (Addison-WesleyReading, Mass., 1977), p. 177.

L. A. Vasil'ev, Schlieren Methods (Israel Program Scientific Trans., New York, 1971), pp. 10–11.

H. Schardin, “Schlieren methods and their applications,” NASA Rep. TT-F-12731 (NASA, Greenbelt, Md.; 1970) [Ergeb. Exakten Naturwiss. 20, 303 (1942)].

W. Merzkirch, Flow Visualization (Academic, New York, 1974), pp. 71–102.

G. S. Settles, “Color schlieren optics—a review of techniques and applications,” in Flow Visualization, W. Merzkirch, ed. (Hemisphere, New York, 1982), Vol. 2, pp. 749–759.

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 (11)

Fig. 1
Fig. 1

Schematic drawing of a simple schlieren apparatus.

Fig. 2
Fig. 2

Graphic representation of the HSI color space and its relationship to the R, G, B tristimulus vectors.

Fig. 3
Fig. 3

Pixel layout of a Cartesian filter: (a) the nonoptimized filter is seen with the accompanying index stripes necessary for registration; (b) the optimized filter, in which these stripes are discarded and replaced with tapered saturation zones.

Fig. 4
Fig. 4

Original (ideal) filter. (a) Spatially dependent transmittivity function of an ideal Cartesian. (b) The hue versus position data obtained when this filter was scanned. (c) The R, G, and B values corresponding to this scan. (d) The pair function derived from these data.

Fig. 5
Fig. 5

R, G, and B tristimulus values used to generate an ideal filter.

Fig. 6
Fig. 6

Optimized filter. (a) Spatially dependent transmittivity function of an optimized filter, showing the tapered saturation zones. (b) The resulting hue versus position data obtained when this filter was scanned. (c) The associated tristimulus components. (d) The pair function derived from these data.

Fig. 7
Fig. 7

Temporal variations in the R, G, and B components and hue of a stablized xenon arc lamp.

Fig. 8
Fig. 8

Configuration of a gas-filled wedge for the generation of known ray deflections.

Fig. 9
Fig. 9

Plot depicting predicted deflection angles as a function of gas pressure versus measured ray deflections at the plane of the filter for the gas wedge of Fig. 8. The best fit to the slope of this line corresponds to the focal length of the decollimating lens. The error bars represent the accuracy of the gauge used to determine the gas pressure.

Fig. 10
Fig. 10

Plot of the surface slope of a 75-mm-diameter BK-7 glass window.

Fig. 11
Fig. 11

(a) Raw data and (b) temperature field reconstruction of a radiantly heated pool of 10-cS silicon oil.

Equations (7)

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

θ exit tan θ exit = L n d l .
d = f c tan θ exit f c θ exit ,
I = R + G + B 3 ,
S = 1 min ( R , G , B ) I ,
H = cos 1 { [ ( R G ) + ( R B ) ] [ ( R G ) 2 + ( R B ) ( G B ) ] 1 / 2 } .
H / x = const = 2 π X max ,
H ( x ) = 2 π { 1 1 X max | x | } .

Metrics