0

Why does a hologram when divided still maintain the total image of the subject? And one would imagine at the atomic scale when the hologram is separated to such a small set of atoms the total image would no longer be present in that section. What is at work here and when would the total image stop being present?

StarDrop9
  • 1,211
  • 1
    A fraction of the original hologram doesn't retain the total image. At best it retains a less resolved version of the image and it has only a fraction of the viewing angle of the complete hologram. – CuriousOne Sep 09 '15 at 15:30
  • If you break a hologram in two, however, you end up with two holograms, each of which shows the entire original scene, although from slightly different points of view. – StarDrop9 Sep 09 '15 at 15:40
  • Need a more complete answer than CuriousOne has contributed. – StarDrop9 Sep 09 '15 at 15:46
  • I would suggest to modify the question. You are basically starting out with a false statement rather than asking "How does the image quality of a hologram degrade when it is cut down in size.". – CuriousOne Sep 09 '15 at 15:51
  • 1
    Since each point in the object illuminates all of the hologram, the whole object can be reconstructed from a small part of the hologram. Thus, a hologram can be broken up into small pieces and each one will enable the whole of the original object to be imaged. One does, however, lose information and the spatial resolution gets worse as the size of the hologram is decreased — the image becomes "fuzzier". The field of view is also reduced, and the viewer will have to change position to see different parts of the scene. – StarDrop9 Sep 09 '15 at 15:58
  • I definitely take odds that the question started out with is false. CuriousOne if you persist in driving an answer be little more patient and creative maybe even think harder and longer. The point isn't that the image degrades or loses resolution. The point is each point illuminates all of the hologram no matter the resolution falls off. – StarDrop9 Sep 09 '15 at 16:10
  • To be slightly more precise: a hologram can be understood as being a Fourier transform of the image (it's a little more complex because the phase information is lost, but anyway). So the recording is like a Fourier transformation and the viewing is the inverse Fourier transform. Cutting the hologram in pieces is like multiplying the Fourier transform with an aperture function (it's either 1 for the parts that are there or 0 for those that are lost). The inverse transform then acts like a convolution of the inverse transform of the aperture function with the original image. /handwaving off :-) – CuriousOne Sep 09 '15 at 16:26
  • Ihope you're aware that holograms depend on varying the phase difference here and there and that below the fundamental particle (molecules or larger) you cannot maintain the proper phase relationships. – Carl Witthoft Sep 09 '15 at 17:15
  • Yes I think that is where we are taking this question. I believe there are at least three reference laser beams at work here and the wavelength of the laser being recorded on the holographic plate will be the limiting factor and the area necessary to maintain the phase conjugation as you point out. Thank You. – StarDrop9 Sep 09 '15 at 18:01

0 Answers0