Black out

[Anthony P]

Hope this is the right forum.
As a laser hobbyist one of my pursuits is holography. A major problem I have encountered with green laser holograms is reflected or scattered light which clouds photo plates. In the past a bit flat black rustoleum here and there works fine for low power HeNe. With the PL530 @ about 50mW or so, this paint is totally inadequate.
I have read about Vantablack and it is a facinating substance, perfect for the job. Unfortunately it is not available to the public and enough of it would cost more than my house. Even the publicly available Singularity Black is insanely expensive. ( it would make good goth nail polish)lol.

Question: Can anyone recommend a practical paint for light absorption?

 

[Immo1282]

A British artist called Stuart Semple who was unhappy with Anish Kapoor's exclusivity on Vantablack came out with this product which he calls "Black 2.0".
http://stuartsemple.com/project/black-v1-0-beta-worlds-mattest-flattest-black-art-material/

Basically it's a poor-man's version of Singularity black - £12 for a bottle instead of the $75 that a quick google search pulled up on it... No idea if shipping it to the US is insanely expensive - but I could always forward you a bottle if Semple's site wanted an unreasonable amount for shipping.

Unsure if it'd do the job for very high power lasers, but for it's price (and the 50mW you can get out of your PL530) it's probably better than the paint you used before...

 

[paul1598419]

I have found the judicious use of beam stops and light blocks to work best for this problem. If you take time to block it from reaching your plate you might not need to do it every time you shoot a hologram. It can be time consuming, but worth it.

 

[Anthony P]

Thanks Immo. I found some black2.0 on ebay and ordered it. 20 bucks for 150ml is worth a try.

Thanks Paul. As always your advice is greatly appreciated. I have made some shutter mods that I will test this weekend. With HeNe, a simple black card in front if the laser was fine for shutter. If I try that with the green laser, there is enough reflection from card to light up the whole room. BTW I got my first reflection hologram to turn out. It is horrible quality... but at least it is there. Now I have something to work with.

 

[paul1598419]

That's great. I knew you'd get one eventually. I would look into driving the 530nm laser at a lower current level. You likely don't need that much exposure. But, green is much more visible to our eyes than red, so you will still see more light even when you get it down to 10 mW.

 

[Anthony P]

I have tried the stuart Semlpe black. It is, in fact, very matte and heavily pigmented. It is much better than Rustoleum, but it is not vantablack. Vantatblack is not really a paint though. It is actually an amalgamation of sub-atomic particles that parially removes the coated object from our space-time continuum rendering it impercievable.( that is the first emoji I ever used in my life).
I have been busy fabricating beam stops. I never realized how much laser stuff Wal-mart has in their arts and crafts department. Now I feel like a whole different kind of nerd.

 

[Immo1282]

Yeah - Vantablack is a forest of tiny carbon nanotubes No paint's gonna replicate that. Like the spiky walls of an anechoic chamber, but scaled down so they trap light instead of sound waves... Shame that it's not accessible or affordable

 

[paul1598419]

Rustoleum is useless for this application. I actually have some black Rustoleum from years ago when I was trying different blacks for a TEC coating for LPMs. I still have all of it because it didn't help advance my project at all.

 

[Mandelvolt]

New holographer here...
Trying my hand at RGB holography. I'm still working on a remote beamstop, but I'm thinking something like a black box with a hole in one side to catch the beam, that way only a very narrow angle of reflection can escape the box. Obviously this is more 3d and heavier than a simple beam stop, although that might be something to try is physically blocking the beam using something like a black tube or box with a little hole in the end depending on how much space you have between optical elements.