What is Hologram: Definition and 36 Discussions

Holography is a technique which enables a wavefront to be recorded and later re-constructed. Holography is best known as a method of generating three-dimensional images but it also has a wide range of other applications. In principle, it is possible to make a hologram for any type of wave.
A hologram is made by superimposing a second wavefront (normally called the reference beam) on the wavefront of interest, thereby generating an interference pattern which is recorded on a physical medium. When only the second wavefront illuminates the interference pattern, it is diffracted to recreate the original wavefront. Holograms can also be computer-generated by modelling the two wavefronts and adding them together digitally. The resulting digital image is then printed onto a suitable mask or film and illuminated by a suitable source to reconstruct the wavefront of interest.

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  1. rogdal

    I Hologram recording on photorefractive material

    Good morning, I am developing an experiment on how to study the kinetics of etching/erasure of holographic lattices in a photorefractive material and I have some doubts about the procedure to follow. I have a single-mode He-Ne laser with monochromatic light of wavelength 632.8 nm and the...
  2. M

    I Why does quantum mechanics believe that gravity is a field?

    According to general relativity, gravity is simply the side-effect of bending the geometry of space-time. As a thought experiment imagine a 3D image being projected from a 2D hologram - the distance between the actual 2D pixels in the 2D plane always remains constant, yet depending on the shape...
  3. M

    Controlling light diffraction angle with a holographic "lens"

    I'm a physics student, and working on a class project that requires coming up with a method to control the exit angle (diffraction angle) of a monochromatic light source. For example, taking a laser (monochromatic, coherent light source), spreading the beam, and directing the light at a piece...
  4. P

    Optics Lab Project Holographic Weapon Sight

    Good evening everyone. For my third year optics course we have to do a research lab that includes a lab component for a project. Our prof has suggested we look into something that interests us an design a lab around it. Personally I have always had an interest in military technology and was...
  5. N

    A Hologram theory and quantum physics = existential crisis

    Hello, here there are 2 things (one about hologramic universe and the other about a quantum physics test similar to the slit lamp. The first one is about the Bohm and Pibram as well as one about Alain Aspect 1982 study: articles about their theories...
  6. SteveSA

    B Perhaps a silly analogy - hologram light source retreating?

    Hi everyone I would love to get some feedback on this silly idea I had when thinking of the balloon analogy. Another way to achieve the same effect - at least in 2 dimensions - is to move a projector further away from a screen - everything expands relatively. If the universe is a 2d hologram...
  7. J

    B Create Your Own Hologram for Beginners

    hello! i am trying to make a hologram. buy lasers, isolation table, spreading optic, etc... I have no idea of phisics or maths, i study photography but the subject interests me so much. I have a few books about it. Do you think it is possible to make a simple hologram without any knowledge of...
  8. 3301

    How is this hologram created and projected?

    Recently i stumbled upon this video and got me confused. Any one seen this before? Better yet.. can someone explain how can this hologram work? Also on this site i`ve found this: "
  9. kelvin490

    How Holography Works: Explained

    To make a hologram a film is exposed to an incident plane wave and wave from the object to record the interference pattern on the film. The principle is commonly explained in a way like that in p.1212 of "University Physics" (...
  10. Malaxus

    Question about Holograms and 3D mid air images, videos, etc.

    I am very curious about holograms and if there is a possible way to project 3D , mid-air images and videos on air with no holographic screen (The Princess Leia hologram in Star Wars). If it is not possible, how long till they actually start arriving to the world and how will they work/operate?
  11. T

    Two hologram halves brought together

    A google search will bring up a lot of pages talking about cutting a hologram in halve and ending up with two smaller copies of the original hologram. What about the reverse? I can't find anything which says what happens when you stick the two pieces together again. Will you end up with two...
  12. P

    Very small holographic laser projectors and diffraction.

    In thinking about what it would take to make a feasible invisibility cloak or holographic disguise or perfect hologram room, I've imagined something that works like this: A light beam "image" is projected onto a device designed to refract or reflect it in all directions, but only 1 color in any...
  13. ghost313

    Learn How to Make a Hologram: Step-by-Step Guide & Equations

    Can anyone tell me,or send me a link to a paper on holograms,how to make them and if possible their equations?
  14. A

    Is Our Universe Truly a Hologram?

    I recently read this:- http://www.dailymail.co.uk/sciencetech/article-2522482/Is-universe-hologram-Physicists-believe-live-projection.html Since I'm not well versed with the current developments in physics, I do not know if this is pseudo-science or true. Anyone care to explain?
  15. Greg Bernhardt

    Evidence that Maldacena’s hologram conjecture is true

    Simulations back up theory that Universe is a hologram http://www.nature.com/news/simulations-back-up-theory-that-universe-is-a-hologram-1.14328
  16. P

    Hawking Radiation and the Hologram Theory

    According to Hawking Radiation, a black hole if left alone will eventually evaporate. As the black hole loses mass the area of the event horizon shrinks until both are gone. The Hologram Theory says that as matter falls past the event horizon all the information pertaining to that matter is...
  17. C

    Neutralize EMF Radiation w/ Vibrational Energy Hologram

    A hologram with "vibrational energy" to neutralize EMF radiation within its radius? http://www.safespaceprotection.com/qanda.aspx How do the products work? Our products 'repattern' the electromagnetic field by creating a 'coherent polarizing field effect'. When the charged particles are...
  18. A

    Does Black Hole Information Storage Suggest a Holographic Universe?

    Hi. I've always been fascinated by black holes. I have recently leared something new about them. It is regards to whether or not information that enters a black hole is lost or somehow preserverd? This is an important question because if it is the former case, then black holes would violate...
  19. T

    Software to make computer-generated hologram

    Does anyone know software to make computer-generated holograms? Thanks.
  20. S

    Hologram Question: Exploring the Definition of a Simple Physics Demonstration

    Hello everyone, An interesting discussion has arisen within my physics department. Would this (https://www.amazon.com/dp/B0002W3J7M/?tag=pfamazon01-20) two-sided reflective dish technically fit the definition of a hologram? We often present this demonstration to schoolchildren, talking...
  21. S

    Why could we see a laser hologram?

    How could we see a hologram created by lasers if laser beams do not get in our eyes (it could be dangerous)?
  22. C

    Making a Hologram and Diffraction

    So when they make a hologram they use a laser and it gets shot out and goes through a beam splitter and the one beam bounces off a mirror and then the object they want to make the hologram of , and the other beam bounces off a mirror and when the two beams meet they interfere and then hit the...
  23. A

    Hologram of a car or skyscaper.Is it possible?

    I wrote a project about holograms,but my teacher asked me kind of tricky question. Is it possible to make a hologram of a car or skyescraper?`My answer was not at the moment but probably yes in the future.But is kind a difficult to explain all physics behind this matter. Maybe someone could...
  24. F

    Explaining the Hologram Effect - fawk3s

    "If you tear a hologram in half, you can still see the whole image in each piece. The same is true with smaller and smaller pieces." I don't understand how this works. Can anyone explain? Thanks in advance, fawk3s
  25. C

    Do Holograms Reflect on Surfaces Like Clear Floors?

    hello, It's chitose wonder chick again. First, I don't know where should I put this question so I choose this. ......... yesterday, I talk with my friend about hologram we saw in magazine and something bother me... Dose hologram have refect on objuct? such as clear floor I watch...
  26. L

    Make a Hologram: Materials, Pictures & 3D Objects

    Anyone have any experience making holograms? Where would I buy the materials? Can I make a hologram out of a picture, or does the thing I'm turning into a hologram already have to be 3 dimensional?
  27. J

    MATLAB Create a Hologram with Matlab?

    Create a Hologram with Matlab??! Hi, I have been given a task to mathematically create a hologram of an object so that I can try various reconstruction procedures to obtain the objects field. For simplicity I am assuming the object is a 1*1 pixel in a 256*256 matrix (x,y plane) and it is...
  28. J

    Question About Hologram Property - Seeking Answers

    Someone I know has asked about a certain property of holograms which he said he was shown while he was in school, but i can't figure out why the property should be true. He says that he once saw a video of a demonstration where a light (presumably a laser) was shone through a hologram, and...
  29. K

    3d hologram in vacuum help ?

    3d hologram in vacuum ... help please ? hi everyone I am a software engineer and i want to make a project based on laser or light and don't know a lot in laser (almost nothing), so i will discuss the project i want to do and i will ask some questions about it please? I want to make 3d...
  30. G

    Hologram Universe: Exploring Susskind & t' Hooft's Theory

    I took a look at the back of a book titled "The Black Hole War" by Leonard Susskind. The last sentence of the commentary or summary stated that Susskind and t' Hooft showed that everything in the physical world is actually a hologram projected from the farthest realm of space. What is the...
  31. fargoth

    Solving the Mystery of Hologram Interference Image

    after many experiments with digital holography i finally got the best interference image i could... but after analyzing it, i got my object in two locations! it was supposed to be on the lower right side of the image, but i got it on the upper right side too... any idea why it happened...
  32. N

    Can I use inexpensive laser diodes to create white reflecting hologram ?

    I read the tutorial on http://www.3dimagery.com/ on how to create a white light reflecting hologram but the He-Ne laser is too expensive for me . So I want to ask that can I use inexpensive laser diodes in the place of He-Ne gas lasers . Besides that I see the websites say that the...
  33. N

    Making hologram without optical table ?

    I read the instruction on how to make a hologram at http://www.3dimagenery.com and it says that you need optical table in order to make a hologram but the optical table is quite expensive for me . So, I want to ask that can I make the hologram as in the 3dimagenery website without using a...
  34. N

    How to make a hologram by myself ?

    I want to create a hologram by myself . How can I create it . I know that I need a laser a optic plate . But what is optic plate ? Can I make it by myself ?
  35. z-component

    Hologram be fully 3-dimensional

    I am constructing a hologram device for a school project. The hologram will be made with a HeNe laser, but what can I expect it to actually look like? If constructed correctly, will the hologram be fully 3-dimensional like the original object? I can't find any good pictures of an actual...
  36. R

    Generate Holograms with a Simulator - Get Answers Now

    does anyone know of a program where I can simulate the properties of a hologram, or generate a hologram from an image? thanks :)