Slashdot Mirror
Laser Pointer Holograms
kgb1001001 writes: "A couple of instructors at Lake Forest College and the Kyoto Institute of Technology have put together a nice little page on amateur holography using laser pointer diodes. This home-page gives enough information to get started and also includes an order form for the photographic plates and chemicals needed to develop the holograms. Also, another page discusses the same techniques and materiels, but comes with some nifty pictures (2-d of course) of the final outcome."
Draw them by hand using a compass and plexiglass.
324006
This is the kind of stuff that should be spread among all students... it's so cool that it makes me puke :-)
That's the best way to spread the love for science and to make our curiosity take over our minds... that's the kind of stuff that makes the world go forward.
Well done, keep up the good work!
Here is an informative page about creating your own holograms, and the different types.
Your hair look like poop, Bob! - Wanker.
I knew I'd eventually use those pointers for more than annoying people.
d ucation/Light_and_Optics/Holography/
http://www.shadow.net/~holodi/holobook.htm
This seems to be a rather popular endeavor. Further resources:
http://directory.google.com/Top/Science/Physics/E
Laser pointer holography was originaly developed by Frank DeFreitas. His web site http://www.holoworld.com/holo/diode.html has many pictures of his work. Quite a marvel. You should buy his book. It is very informative. It's about 17 bucks from Amazon.com Its very helpful and takes you step by step in the process and a bit into the history of holograms etc. I'be had great success with his process. It's a bit harder to find his holographic plates, and this isn't exactly the cheapest thing in the world. The plates cost me US$60 for five or six! But the results are great. You CAN'T use this for any kind of forgery because the holograms are on a glass substrate. I suppose it is possible to put it on plastic somehow. But beats me on how to do it.
W-S
It was really quite interesting to setup. The ones we made turned out so-so. The problem was the only room that we had to create the holograms in was on the 2nd floor of the house. So all kinds of vibrations from below caused some problems.
If ur going 2 do this urself, I'd advise setting up the project in a school's darkroom or janitor's closet with a cement floor.
Make sure ur far away from streets and all forms of noise (and therefore vibrations) as this REALLY causes problems.
FLXkid (the Visual Dataflex Guru)
...
Better VDF than VD!
Better VDF than VD...check it out: Data Access
Man: Is your uh, is your wife interested in....holography, ay? 'Holographs, ay', he asked him knowingly?
Squire: Holography?
Man: Snap snap, grin grin, wink wink, nudge nudge, say no more?
Squire: Laser pointer diodes, eh?
Man: They could be, they could be taken with diodes. Candid, you know, CANDID holography?
Squire: No, no I'm afraid we don't have a laser pointer.
I watched C-beams glitter in the dark near the Tannhauser gate.
The type of holographic labels companies use are completely different from what is being described here.
:)
The process being discussed uses glass plates, chemical developer and is monochromatic. The type of holography you're refering to uses micro embossed metal to produce an image.
I dont think they have anything to worry about.
Anyway, we did this for a science class in college, and it was a lot of fun even though the image of my pocket watch came out kinda dim. You need an object with a really reflective surface to get something sharp looking, plus a steady hand and a room with solid floor. There's a lot of variables to account for and a lot of people simply ended up with a glass plates with some cool looking lines on it.
The only catch is that these holograms are only visible at a very narrow range of angles. Not just the two angles of rotation to your eye, but also the two angles of rotation to the point light source. So it can take a bit of fiddling before you suddenly see something. But when you do, it's very sharp and detailed.
Slashdot monitor for your Mozilla sidebar or Active Desktop.
Those laser pointers you can get with with switchable tips that cause the device to project different 2D images (by multi-slit-diffraction, I suspect) can be fun. One time I was in a hotel up on the tenth floor and I had just bought one of these toys.
... fun!
[Side note: yes, I know this is somewhat off topic, but this thing I'm about to tell you could have amplified effect with 3D projections.]
I stuck on the tip which projected a 'UFO' image, stepped out onto the balcony and shone it onto the ground. I moved it around and after a few seconds I heard some little girl scream "MOMMY!" so then turned it off. Imagine what you could do with one of these things projecting the right 3D image
Get a used HeNe laser off ebay or any Optics surplus, with TEM00 properties (which means the laser is coherent... needed for holography, and you'll be able to make some holograms that have more than a few millimeters of coherence (hense, depth).
:), yeah sometimes it's that crazy, I tried :) ).
Laser Diodes holography really sucks, it's pricey for the result you get, learn the thing with the right basic parts. If you're ready to invest let's say 400$ worth of chemicals films and all, with the idea of doing more in the future, might as well invest in the proper "amateur equipment"
Also: High power laser diodes in a decent spectrum (630-640nm) aren't THAT powerful, or if they are, (more than 5mw) they are pricey. These laser diodes lacks coherence (notice how close are the object from the plates). Without coherence, you don't get depth, without power, you have more chances that your object might move (if the object moves just a quarter of the wavelength, it screws up the hologram), so getting a cheap used 20mW HeNe laser gives you the benifit of power (you won't make a 8x10 with that, unless you have a really stable environment that can take 30+seconds exposure time depending on the object, of course doing the hologram of a fruit might not work too well with that much exposure because only the "fermentation" of the fruit over 30 seconds changes the structure in the nm scale
The only downside of Gas lasers is their lifespan. You can be lucky and it would last for 3-4 years, like you can get one that will last for 6 months, depends on the manufacturer, prices, condition. Normally they give you the tube usage and lifespan. Also, it requires high voltage power supply, which isn't a problem for the low power heNe lasers (under 30mw at the output).
Holography is cool, but it takes patience, a lot of trial/error, and when you want to move a step further, it takes as much money than doing high-end photography (with all the optics and chemicals).
--- Metamoderating abusive downgraders since my 300th post.
www.photologie.net has a geat walkthrough for laser pointer holograms with lots of pictures.
It covers adding more power to the pointer as well and some details for opening the caseing without damageing it.
Bust out your Dremel tool and potentiometer, and use the fish cuz its in French.
the holography that tj describes on his web page is a denisyuk or on-axis reflection hologram, done with a low powered laser on to silver halide based film. the holography that is being used as anti-counterfeiting methods(credit cards, cd's, baseball cards) are using a variation of the whitelight transmission or rainbow hologram. this method requires(typically) a multi-watt, water cooled argon laser with photoresist plates and a highly toxic development procedure. after a photoresist plate hologram is created, a nickel "mother" plate is grown using a plating process(like for choming). this mother plate is used to grow several daughter plates, which in conjunction with heat, pressure, and hard to aquire materials is embossed onto paper and plactics using a hot stamp process. the manufacture of these kind of holograms is just terribly time consuming, expensive, and spans several old-school technologies(photography, photochemistry, electro-plating, web press, foil hot stamping) and requires a small army of people. the security hologram is only security thru obscurity; the return on investment for the manufacturing of these security items is horrible, and the manufacturing of the materials used is built to order(not many people order tem00, 50 watt tunable argon lasers; photoresistplates; mercuric chloride, potassium permanganate, and other obscure toxic materials). all things which are easily tracked from manufacturer to purchaser.
three can keep a secret, if two are dead - benjamin franklin
It's psychosomatic. You need a lobotomy. I'll get a saw.