A New Method for Generating Depth Contours Holographically

Abstract

Employing holographic techniques, Hildebrand and Haines have demonstrated that a multiple frequency source can be used to generate range contours on or near an image. Supplementing their system with an auxiliary imaging system, we show that contours can be generated over much larger surfaces. With our modified system, it is also very easy to generate contours denoting constant depth rather than constant range. Experimental results are presented that show depth contours representing separations of 9.25 micro over a surface area of about 80 cm(2).

Applications of holography

“…When the two images are formed from the two holograms, fringes are again formed with a spacing proportional to the inverse of the wavelength difference. Naturally, multiple sources and multiple wavelengths would produce multiple beam interference fringes, giving more accurate positional location of the contours Haines 1965, Zelenka andVarner 1968).…”

Holographic Interferometry (HI), Infrared Vision and X-Ray Fluorescence (XRF) spectroscopy for the assessment of painted wooden statues: a new integrated approach

“…There are several ways to generate contour maps [27]- [31]. In this work, it is reported the result obtained with an experimental arrangement based on the sandwich holography technique [10], i.e.…”

Contouring by electronic speckle pattern interferometry employing dual beam illumination

“…Holographic methods for measuring surface shapes are based on two-wavelength techniques, 1 altering the refractive index of the medium surrounding the object, 2 sandwich holographic interferometry, 3 and by displacing the object and the illuminating beam. 4 Electronic speckle pattern interferometry (ESPI) an outgrowth of image plane holography, has received some of the direct implementation of the holographic methods.…”