Integraf Diode Vs Generic Laser diode

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thycore
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Integraf Diode Vs Generic Laser diode

Post by thycore »

Hi Everyone !

I'm new to this forum and quite happy to finally have found a place to discuss my newest hobby !

I've spent countless hours on trying to make holograms and burnt something like 30 plates (Integraf & Ultimate) and I must say that maybe 2 holograms only were successful.

I wonder if my set-up might not be the reason why I have so much difficulties.

The first question which comes by making holograms is the laser source, initially I bought the integraf kit and I have a red laser diode with the one I had more or less 100% of my 2 (out of 30) successful holograms.

Somehow this laser diode from Integraf shows funky figures when directing to a wall :
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I thought maybe this is bad and I bought from the internet some other laser red diodes (very cheap, like 10$ the 10 pieces), the diffusion pattern was however rather uniform and "good looking" (at least better looking, were my thoughts).

I 3D printed some "tower" and some "holo plate holder" which I glued to a wood plank (objective of the holo plate holder is to "hide" the glass sides to avoid any beam reflexion to get "inside" the glass and bounce over creating undesired interferences) :
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This set-up simply never gave me any successful hologram (using Ultimate plates).

Would you think the problem is the "diode" ? does it have to be of a particular quality ? (I read on the wiki, a polarized is better), how can we explain the price difference between integraf's diode (35$) compared to the laser diodes we can get for 2$ on amazon ?

Also, would you say it's best to power your diode using Bettery-cells or Lab power source ?
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Thanks for your ideas :)
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thycore
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Re: Integraf Diode Vs Generic Laser diode

Post by thycore »

With integraf led and battery cell I made this using ultimate plate.

There is clearly an overexposition in the middle :
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HoloM
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Re: Integraf Diode Vs Generic Laser diode

Post by HoloM »

Welcome to the world of holography.
The difference between this two diodes may be the coherence length and the tendency of doing mode hops.
So a diode has to be tested, if it suitable for holography.
Some are, some not.
I would say it is normal that you have to do many tests before getting any good result.
The most common problem is stability. Second is exposure time, third is development.
Where have you placed your setup? Have you a holographic table, or doing it on a normal table, or doing it on the ground floor?
Have you done anything for minimizing vibrations?
Where do you live? Out in the calm forest or in a city nearby a heavily used road? Are you on the ground floor, or on the 25th floor?
Did you call exposure time? Which development did you use?
Your plate seems not to be lighted equally. What about spreading the beam with a lens?
For serious experiments I would engage you to invest in a helium neon laser and a small lens.
Use one type of film, don't change it until you get consistent results.
So keep experimenting!
BobH
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Location: Mesa, AZ

Re: Integraf Diode Vs Generic Laser diode

Post by BobH »

I don't think there is anything wrong with your first laser. The patterns you show at the edges of the beam are just dust specks. Those won't cause a problem. The likely cause I see is your plate holder. If the plate is free to wiggle a little in there, that's a huge problem. If the plate is easy to insert and remove, it's waaaay too loose in there. The plate needs to be held against a solid and flat surface, with light spring force holding it against that surface.

Do you glue your objects to the table surface? If not, they could be moving during exposure. I'd tack them down with a couple tiny dabs of glue. My favorite is 5-minute epoxy.
lobaz
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Location: Pilsen, Czech Republic

Re: Integraf Diode Vs Generic Laser diode

Post by lobaz »

I agree with Bob, it is some movement most likely. Try to proceed with the simplest experiment described in the Integraf booklet:
1. Get a sandbox, there should be at least 10 cm of sand.
2. Get a glass about 20-25 cm tall, fill it with sand and put in to the sandbox, try to dig it deep into sand.
3. Take a clothespin, put a laser diode into it, and dig it into the sand filled glass.
4. Turn the laser on. It should illuminate the sand surface at an angle about 45 degrees. Keep it running about 10 minutes before you start the exposure. Use batteries.
5. Take some flat, metal, simple object, such as a coin (just one piece!). Put it into the spot of laser light.
6. Put a card between the laser and the coin so that the card blocks light completely.
7. Put a holographic plate directly on the coin, emulsion facing the coin. Basically, the plate lies directly on the sand. There is also a coin somewhere in the middle.
8. After about a minute or two, slightly lift the card so that the plate is still not illuminated. Hold it in your hand, do not touch anything in the sandbox, hold your breath.
9. Wait about 20 seconds until everything calms down. Then remove the card so that the plate is illuminated.
10. After about 10 seconds, block light again so that the plate is not illuminated. Do it as fast as possible, but do not shove anything in the sandbox. Start breathing again. :)
11. Develop the plate. Ultimate plates are easy with the Ultimate chemistry, other plates may be trickier.

I assume you use a red laser and red sensitive plates.
This process should give you a hologram even in very poor conditions. If you succeed, you can try - one step at a time - to replace components, make more complicated objects, etc.

Good luck!
Petr
142laser
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Re: Integraf Diode Vs Generic Laser diode

Post by 142laser »

Sounds like solid back to basics advice. HI PETR! :) How RU you doing?
lobaz
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Location: Pilsen, Czech Republic

Re: Integraf Diode Vs Generic Laser diode

Post by lobaz »

Indeed, Phil! Very well, thank you, and the lasers send you their best wishes! :)
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