"Hologram" has evolved in meaning over the past 40 years. To Gabor it meant a diffractive "whole picture" recorded by optical interference. Today its meaning very loosely includes much more: HOE's, any image with diffractive effects, and even practically any 3D image regardless of how it works. But the preferred meaning is "a pattern recorded via wave interference", with "wave" being light, sound, radio, or quantum mechanical particles.
Questions tagged [hologram]
100 questions
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Is there a type of hologram that could be used to focus light?
I was wondering if a hologram could be made that could focus light that wasn't in the original hologram. I'm assuming that this would have to be a mathematically constructed hologram as, by my understanding, a hologram of an actual lens can only…
Adrian
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Physics of a hologram and its Fundamental Limitations
I understand the basic principle behind holography as the interference of a scattered wave with a reference beam which is captured using a photographic plate. The photographic plate is further used to recreate the original image by using it as a…
Prathyush
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Is it (theoretically) physically possible to project an image into thin air?
Is there some law of physics that strictly prohibits the projection of 2D or 3D images into thin air (such as holograms in movies) or is a solution to achieve this still up for grabs by an eventual discoverer?
anthonyvd
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Holograms other than light
Normal holograms are, if I understand correctly, what happens when coherent light is passed through something that manipulates the photon's wave functions to be what would have been present had they been reflected off a real 3d object.
Is it…
BenRW
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Can thick-film reflection holograms be used to create true mirrors?
Experimental alert: Someone may be able to answer this question experimentally simply by going to a shopping mall and finding the right piece of holographic jewelry.
My question is whether the type of front-view "thick film" hologram often seen in…
Terry Bollinger
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Computer-Generated Holograms: I'm completely lost. How are they physically implemented?
I have been reading about holography, and I think I understand the general concept, but one thing that has me completely lost is how computer generated holography works in practice.
I think I get the basic idea behind how CGHs work. If we were to…
krfkeith
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What is relation between Holographic principle and Hologram?
What is relation between Holographic principle and Hologram?
The holographic principle is a property of quantum gravity and string theories which states that the description of a volume of space can be thought of as encoded on a boundary to the…
alpha
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Holography versus Young's double slit
In order to see interference fringes in double slit one needs the two slits to be very close (1-2 wavelengths) even using highly coherent laser. But in Holography this condition apparently does not play role. There is interference when the object is…
Mercury
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The need of the reference beam in Holography
For a project, we're investigating how a transmission hologram works. I understand how the process of making this hologram works, but I can't get my head around just one thing. Why would a transmission hologram require a reference beam to illuminate…
P.Yntema
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How does making "pyramid hologram projectors using smartphones" work?
The basis of this question is this video, where a 3D hologram like effect is achieved using a 4 sided hollow pyramid. I don't know if this is holography in the usual sense. Can some one explain this phenomenon in a detailed, mathematical way using…
biryani
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Possibility of a free-space hologram
Holograms are real. But they are not what sci-fi calls holograms.
From a simple geometric optics standpoint we can see that in order to create the illusion of an object there must be some sort of light-emitting or light-modulating surface on the…
2012rcampion
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How to understand holography and hologram
I've spent some time reading wiki etc. What I get now is that apart from the normal light amplitude information, holograms also record the phase information of light. But this is so difficult for me to understand. In my understanding to display the…
zinking
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Does a "reflected" hologram produce a caustic in the shape of the original object?
Imagine you make a transmission hologram, ala the standard picture. Now you take your photographic plate, and everywhere it is transparent, you put a thin reflective layer on, and everywhere it is opaque, you make it transparent (more accurately,…
Craig
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What's a tangible explanation of the angular spectrum in optics?
In order to understand image reconstruction from a diffraction pattern as applied in in-line holography, I'm reading Joseph Goodman's Introduction to Fourier Optics. Chapter 3.10 discusses the angular spectrum. For a monochromatic planar wave along…
smcs
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How does a holographic object change perspective when the image is rotated?
Fundamentally I want to know: How do holograms work?
The problem with that question is that normally you will end up with pages and pages talking about:
a laser
a beam splitter
a diffuser
the object being imaged
object beam
reference…
Ian Boyd
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