I have read about the types of plates and special films that the holograms can be created on. Are there other substances that it will show up on as well? Like can you create a hologram on a clear plastic bottle or on glass?
Also, in looking at pictures of holograms online I have come across pictures of hologram overlays that companies sell. These are printed on what appears to be clear plastic. Is making a hologram on this type of material the same as make a hologram on a plate?
And here's the plastic hologram overlay I was talking about:
I'm sorry if these are basic questions, I've just started researching how holograms are created.
Those are embossed holograms, see the recording materials part of the wiki (linked in the top post).
In theory you could put them on a plastic bottle or even a glass (both requiring quite a bit of engineering, especially the latter) but you would not be able to see them without the reflective coating normally backing an embossed hologram. You could simply use a sticker of course.
These transparent overlays are a variation of embossed holograms. Without the metallized backing these mass-produced images are visible but not very bright; however doping up the coatings that the image is embossed into (the plastic film itself is way too hard to emboss directly into; a thin layer called the emboss coat is applied to the foil and that's what takes the heat and pressure to form the image) to raise its refractive index makes a brighter image.
The amount of light reflected from a surface is not only dependent upon the polarization vector and the angle of incidence but the refractive index change between the two media. So the image you uploaded is an example of a hologram embossed onto a High Refractive Index or HRI coating. The advantage is that you can put this on top of photos or documents and see the info as well as the holographic image. As an additional element of security, these types of foils are of a controlled circulation; the average person might not be able to buy them.
I noticed that this guy from the Netherlands makes and sells glass plate holograms. I'm assuming this means his created the hologram directly on the glass plate and did not just place a piece of glass over the holographic film. He's had some amazing results.
I was wondering about glass specifically because I have a friend who's into amateur glass blowing and he can created glass flowers and figurines and whatnot. I was wondering about the possibility of creating a hologram effect on the glass to give it an amazing look. Can the emboss coat that Ed mentioned for the overlays be placed on top of glass to enable the hologram to be created?
Ed, thank you for your knowledge of the transparent overlay holograms. So if I understand you correctly, these are created by taking the transparent clear overlays and coating them with an emboss coat that the hologram can be recorded onto? Where exactly does the foil come into play?
Sorry if these are really specific questions. I'm just curious about the ability to create holograms on other mediums.
The glass in those holograms is just the carrier for an emulsion ... those holograms also need special lighting for viewing, unlike the horizontal parallax (ie. perspective shifts only if you move horizontally, not if you move vertically) rainbow hologram in your original post.
Ed Wesly wrote:As an additional element of security, these types of foils are of a controlled circulation; the average person might not be able to buy them.
Hmm, so is this why Vikuiti transflective polarizers nearly all have build in diffusers? (Except one, which they only sell to LCD OEMs.)
I'm kind of using the terms film and foil interchangeably, but they are only the base that carries the hologram.
There is a subtle distinction between recording a hologram, which implies exposure to laser light, kind of like recording music. The embossed holograms are replicated, meaning they never see the light of laser, but are run through a machine where the holographc pattern is tranferred into the material, not unlike a vinyl record is molded from a master stamper.
Are you guys up to 4 wave degenerate mixing or what? My curiousity is piqued.
If LiNBo3 is like Barium Titanate, then it's like up there in the DCG like region. But usually you expose about a millimeter or so at a time, so the exposure time is relatively short.
Any time you find a new material you kind of log it in the back of your mind. I like the data storage posibilities of Lithium Niobate.
One could use 4 wave degenerency mixing to spread a laser beam if you did not have a lens. :whistle:
No really till you mentioned I had not heard of it. While the math was pretty easy to follow I could not come up with an application. What would it be used for?
Another one that caught my eye was a patent for embossing diffraction gratings in sugar.
