Questions tagged [hologram]

"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.

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Is there a way of changing air refractivity?

Is there any kind of way/equipment that can change the air refractive index? For example, a mirage is hot air refracting light in a certain way, making it look like water. The best I could think of ...
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3D holographic image reconstruction in optics

I am trying to understand how 3D reconstruction of holographic images work. I have a basic knowledge of the holography principle in optics, and that there are several methods for phase retrieval and ...
epsilon's user avatar
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Where is the focus point on a picture with full parallax?

Let's assume I have a theoretical display that can show a different flat picture depending on the viewer's location. It would provide different images to the left and right eyes of a human observer. A ...
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3D hologram point from lasers [closed]

Firstly, I'm not a physics guy. I want to try to create a 3D hologram point with lasers. As I know, if I have at least 3 lasers in the same wavelength and their beam is crossing each other at a single ...
Korte Alma's user avatar
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What happens when holograms get "too big"?

Since a hologram is a 3D object represented on a 2D surface... 3D objects scale like $L^3$ whereas 2D objects scales as $L^2$. Thus the information density scales as $L^3/L^2=L$. This would mean (...
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Can a hologram be programmed to emit a specific frequency of EM radiation?

Do holograms emit EM radiation, or is it possible to program a hologram to emit specific frequencies of EM? If possible, would it require light shining on the hologram to emit the EM? I am asking this ...
Jeremy Gottfried's user avatar
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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 ...
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What is the maximum virtual depth achievable in a printed hologram?

I remember a few years ago printed holograms were quite fashionable. Even though they still had different colors from reality, I found them quite impressing. I wonder if there has been any progress in ...
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Holograms as a superposition of many individual interference patterns

I've recently started reading about non-linear optics and holograms. While I do understand the basics of how holograms are made, by superposing the reference waveform on the object waveform over a ...
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Kirchhoff Diffraction for backwards wave propagation

Classic Kirchhoff Diffraction integral for a monochromatic wave is formulated with a restriction that it's only applicable to a point that's outside of the volume enclosed by the integration surface ...
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Metasurface holography as a principle behind volumetric displays?

Disclaimer: By no means am I a physicist of any kind so complete inability to grasp complex physical concepts without spending ridiculously unreasonable amounts of time on corresponding research is a ...
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Hologram: At the "crux" of the hologram, is there any potential for wave-wave interaction?

Starting with Gabor's original 1948 paper: https://www.nature.com/articles/Art56 And continuing where that paper left off with Gabor's Nobel Prize paper, https://www.nobelprize.org/uploads/2018/06/...
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Electrons and Positrons: What happens when a positron beam in-phase with diffracted electrons is used to make a hologram with the anti-electrons?

Suppose two independent beams of positrons and electrons are filtered such that each is in phase with the other (correction: this probably isn't possible, although terminology to this effect is out ...
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Is the Standing Wave of a particle Hologram "interactive"?

In other words, suppose one creates a particle hologram -- no photo reaction, just a standing waveform in space. Suppose the particle is something we are skilled at manipulating, like an electron. ...
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Matter Holograms: What would be involved?

With photons, holograms are easy: shine laser light at a slit with an appropriate width, get a diffraction. Shine laser light that is in-phase with the source light at the right spot downstream of the ...
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What are the effects of the real image formed by the hologram?

Interference effects of hologram film produces a virtual image at the position of the original object and a real image an equal distance away. Would the real image distort the virtual image to an ...
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Hologram Questions

How does a hologram create parallax, compared to a photograph? If a hologram's purpose is to reproduce the light field, what part of that field creates parallax (angle, magnitude or position)?
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Mirascope Holograms

So I just realised that 3d hologram fan projectors are now a thing, and the quality looks quite good (search Ashata 3d hologram fan projector). However, an inherent problem with them is that the image ...
Richard Goodman's user avatar
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Information in Holograms

I was reading about Holograms, and I read something to the effect of the following statement - "In a hologram, any part of the hologram with sufficient size contains the whole of the stored ...
ramseysdream111's user avatar
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What is the term for the simple, label/sticker like holograms?

From my everyday experience I can say that there are 2 types of holograms. One is the simple type that one can find on the important papers, paper money, as excise marks on the alcoholic beverages, as ...
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Possibility of Star Wars style holograms [closed]

We’ve all probably seen those neat little hologram projectors in franchises like Star Wars, are holograms on the level we see them in Star Wars possible? If so, what are some approaches to this type ...
Boo Radley's user avatar
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Can an optical phased array be used to create free-floating holograms?

Frustratingly, most sources I've found about optical phased arrays only state that they can be used for "holograms" but do not explain what that means. Can optical phased arrays be used for "Star ...
Michael Stachowsky's user avatar
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Calculating maximum allowable velocity of an object during holography

I am working through some questions in preparation for an upcoming exam and the following has me doubting myself: An experiment takes $x$ seconds to create a hologram of an object using $\lambda$ nm ...
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Holographic "lens" - controlling light diffraction angles with silver halide film

I'm trying to develop a way to control the "exit angle" (diffraction angle) of a monochromatic light source. For example: taking a laser; spreading the beam; and directing the light at a piece of ...
Digiman Brunnell's user avatar
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Holographic planetarium

Discussing the possibility of building a planetary with some colleagues, we started wondering about the theoretical idea of a planetarium dome based on a multichannel CGH able to show the sky of ...
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Holograms and Entanglement: Does recording an entangled signal in a hologram “observe” the entangled state?

Suppose I have two photons $A$ and $B$, which are entangled. As I have had it explained to me, entanglement works more or less as follows: I observe or measure $A$, and find $A=S_a$, where $S_a$ ...
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Are holograms in midair physically possible? [duplicate]

Is it possible for holograms, as in 3D projections of light in midair, to exist? Consider this image. If a projector, placed in the same position as the gray circle in the first image, were to ...
Curious Fish's user avatar
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Is it possible to make full-colour Holography using three lasers and three separate holograms?

Holograms need monochromatic coherent light sources like lasers so that the reference light can interfere with the light scattered by the object. Illuminating the holograms, the stored interference ...
Saurabh Shringarpure's user avatar
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Holographic magnification and the requirement of single wavelength coherent reference wave

How is holographic magnification for different wavelength reference beams consistent with the requirement of illuminating the hologram with light with wavelength same as the reference beam? If we ...
Saurabh Shringarpure's user avatar
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Where can I learn about holograms?

I want to learn about holograms. I have zero knowledge of how they work. How can I start? I tried using Google but I cannot decide where to and how to start. Can you suggest any good sites for this ...
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Can Young's double slit experiment be considered a holographic setup?

As described in his landmark paper on holography, "A new microscopic principle", Denis Gabor sent coherent light through a transparent plate with some black letters on it. The light that was ...
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Can single photons make a hologram over time

INTRO. In the parallel slit experiment, single photons ejected from the source at different times still seem to interfere to make a fringe pattern, which in a sufficientliy long exposure time becomes ...
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Sampling theorem for in-line digital holography

In digital holography, the image sensor must have a sufficient pixel density. The book New Techniques in Digital Holography by Pascal Picart and others, the following condition is given: ...
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How do self-developing holographic plates work?

Litiholo started working on self-developing plates in mid-2004 and managed to achieve its goal and started selling these no-fuss self-developing hologram kits that produce pretty good results. ...
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How can 2D flat holograms be considered holograms?

When I think of a hologram I imagine this where you shine a beam of laser light onto a holographic film to reproduce an object beam and see a virtual image of an object that can be viewed from many ...
zld123's user avatar
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Can we see "imaginary" light beams?

When a reference beam, R, interferes with an object beam, O, the interference pattern is captured by a holographic plate. When reconstructing the image, the reference beam is incident on the ...
zld123's user avatar
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What happens when a reference beam passes through a holographic plate?

Here is my understanding of how holograms work: A holographic plate captures the interference pattern between a reference beam and an object beam. When reconstructing the hologram, the reference beam ...
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How much can we infer internal structure from a hologram?

How much can we infer internal structure eg of an arbitrary object, like a sphere or cell, from a holographic interference pattern on its surface?
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Magnification in Holographic Microscopy

The book "Introduction to Optics" by Frank, Leno, and Leno Pedrotti, Ed 3, makes the claim that It can be shown that if the reconstructing light of wavelength $\lambda_r$ is longer than the ...
Ulad Kasach's user avatar
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What is the bright spot in reflective digital holographic microscopy and how to remove it?

We are working on reflective DHM and the system looks like the setup in figure 1. We are facing a severe problem of reflection in the system. Apart from the reference beam and object beam, there is ...
thomas0708's user avatar
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1 answer
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How do holographic mirrors work?

I found this hologram on a book. Apart from the usual rainbow colors, it sported a convex mirror effect on it. Here, you can see my phone's reflection in the tiny circles. It would be ...
AlphaLife's user avatar
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How to Approximate the Maximum Diameter of a Particle in In-line Holography

The in-line, digital holographic system that I am designing is similar to this article, https://www.ncbi.nlm.nih.gov/pubmed/21460907, which images a range of particles present in clouds. I understand ...
Don Abbot's user avatar
2 votes
1 answer
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(Fresnel) diffraction in on-axis holography

In on-axis holography one can consider the plane wave from source the scattered wave from object (spherical if the object is a point) Then it is possible to model the transmission on the ...
Sørën's user avatar
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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 ...
smcs's user avatar
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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 ...
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What type of LED to use with a 100 micrometer pinhole for in-line digital holography?

I want to set up an in-line digital holographic microscope that is similar to the one describe in the article, A Study of Digital In-Line Holographic Microscopy for Malaria Detection, which is they ...
Don Abbot's user avatar
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"Half-life" of a holographic grating imprinted on gold?

Reading further about gold after reading about Warren Buffet's 20 meter gold cube estimate in the BBC's How much gold is there in the world? I came across images of a kinebar which is an optical ...
uhoh's user avatar
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Setting Up In-line Digital Holography

I would like to set up an in-line digital holography system to image plankton samples. The set up consist of a laser that project through an objective which will transmit through a pinhole. In the ...
Don Abbot's user avatar
1 vote
1 answer
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Virtual and real in the case of hologram images?

Are the terms virtual and real applicable to hologram images? Is the hologram image real if the observer sees it in front of the photographic plate, so he could 'touch' it, and virtual if the observer ...
jkien's user avatar
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What information is lost when you view only a piece of broken hologram?

When a hologram is broken into pieces, you can still see the whole object from any piece of them, but I am wondering what information is lost in each of them, does the hologram images look the same ...
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