Hologram of a car or skyscaper.Is it possible?

agentas · Post by **agentas** » Mon Jun 14, 2010 7:43 am

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 give me a link where i can find answer or give a short explanation. Thank you

DJ Mathson · Post by **DJ Mathson** » Mon Jun 14, 2010 1:40 pm

Search the web for holographic stereogram.

ron olson · Post by **ron olson** » Mon Jun 14, 2010 2:11 pm

I believe the University of Toronto produced a transmission hologram of a sports car using their 10 Joule, Q-switched ruby laser. The skyscraper - really anything much larger than car - becomes extremely problematic because of the laser energy and coherence required. As a rule of thumb for my studio I work with pretty much any subject that can walk, be led, or carried through my front door (standard size).

agentas · Post by **agentas** » Mon Jun 14, 2010 2:42 pm

ron olson wrote:I believe the University of Toronto produced a transmission hologram of a sports car using their 10 Joule, Q-switched ruby laser. The skyscraper - really anything much larger than car - becomes extremely problematic because of the laser energy and coherence required. As a rule of thumb for my studio I work with pretty much any subject that can walk, be led, or carried through my front door (standard size).

Ok but than what size is a hologram?The size of the car?3mx2m?How it is possible to illiuminate all car with laser beam?I am sorry but it is very difficult to believe this

BobH · Post by **BobH** » Mon Jun 14, 2010 3:24 pm

A 4"x5" hologram can record the contents of an entire room. It would be like looking through a little window. The room can easily be lit with laser light by hitting diffusers placed around the room with beams, just like light bulbs would be. The size of the hologram can be as big as the wall.

Ed Wesly · Post by **Ed Wesly** » Mon Jun 14, 2010 7:55 pm

Any object can be recorded if you have enough laser power. I have holograms of myself on a motorcycle, Dr. Tung Jeong, some of my friends including an S & M model, all shot when I worked at FermiLab and go to use their large pulsed Ruby laser. My avatar on this forum also dates from this era.

They are 30 by 40 cm plates or film, laser lit, and you can see the whole volume of the room, floor, ceiling, two or three of the walls, garbage cans, the person pushing the button on the laser. They are or sale, if interested, please PM me via this forum.

holo_cyware · Post by **holo_cyware** » Tue Jun 15, 2010 5:35 am

The holographic stereograms are a "dirty" solution to the problem of getting a skyscrapper into a hologram. Basically you can get anything on this, since it is made of images that can be computer generated. I won't call it a hologram though. To me it's a way of creating a very high resolution stereogram and nothing else. (search for "rabbithole hologram" on youtube)

To answer your question, if you have access to some Los Alamos visible wavelength laser that for some odd reason it is fitted with an etalon so it gives a coherence of hundreds of meters, then yes, you can probably make a a real hologram of a skyscraper, Denisyuk style. I don't even want to calculate the power needed though. While I know there are quite very powerfull Nd lasers, doubler/ktp crystal must be huge (think fistsize or more). But since I don't know yet how many MJ would be needed I'm just farting out of my brain.

It is indeed a catchy question, and your teacher probably wanted to underline the "superiority" of the classical photo technology.

agentas · Post by **agentas** » Tue Jun 15, 2010 8:01 am

I understant that we need a powerful laser to get a hologram of skyscraper but dont we need also to have very big lense in order to illiuminate whole skyscraper ant once.I think it would be very difficult to make such lens.Am i right?

Tom B. · Post by **Tom B.** » Sat Jun 19, 2010 6:50 am

agentas wrote:I understant that we need a powerful laser to get a hologram of skyscraper but dont we need also to have very big lense in order to illiuminate whole skyscraper ant once.I think it would be very difficult to make such lens.Am i right?

A small lens could easily spread the beam enough to light the skyscraper. Due to losses from the glass and coatings, it would quickly be destroyed by the megawatt coherent laser pulse needed for this job, but lenses are cheap. You would need a pulsed laser since the skyscraper even in calm air is swaying quite a bit from random seismic vibration and internal elevators etc.

MfA · Post by **MfA** » Tue Jun 22, 2010 7:14 pm

holo_cyware wrote:The holographic stereograms are a "dirty" solution to the problem of getting a skyscrapper into a hologram. Basically you can get anything on this, since it is made of images that can be computer generated. I won't call it a hologram though. To me it's a way of creating a very high resolution stereogram and nothing else. (search for "rabbithole hologram" on youtube)

The pixelized methods Zebra, Rabbithole and a couple of others use are not angle multiplexed stereograms. They can do full parallax.