Laser Wall

FabLab said:

They do, but they are not near the vents so it's not an issue. I have not yet tested any lasers. I have order a 5mw green laser diode to try it out but it hasn't come in yet. I think water mist would be the best way to go, but one of the higher ups at the lab said that it would leave too much water. But I was thinking I could probably do it if I had some way to prevent the liquid from building up.

Click to expand...

5mW diode or 5mW DPSS? Could you link us to what you bought? It's entirely possible that it's advertised as "5mW" but is in fact significantly more than 5mW - just something to be aware of.

I bought it off amazon: https://www.amazon.com/Green-Lasers...=1467314965&sr=8-3&keywords=green+laser+diode

I'm clearly not an expert on lasers so I wasn't really sure where to purchase it from. And should I also be worried about infrared radiation?

FabLab said:

I bought it off amazon: https://www.amazon.com/Green-Lasers...=1467314965&sr=8-3&keywords=green+laser+diode

I'm clearly not an expert on lasers so I wasn't really sure where to purchase it from. And should I also be worried about infrared radiation?

Click to expand...

IR may be a concern - green output power may also be a concern. The seller may be able to confirm the presence of an IR filter - although I'm not sure you can contact them directly through Amazon? You can usually confirm that yourself too - will see if I can find a link for you. Doubtful that they'd be able to confirm the output power with an actual power reading.

Hopefully someone here has tried one of these and can confirm that the output is IR filtered and actually ~5mW.

You may open yourself up to all sorts of liabilities if it turns out your module is doing 10x is rated power and ends up causing someone eye damage, especially if it's in a publicly accessible space - that usually has an effect on what regulations apply depending on your location.

For example - we didn't strictly follow the regulations at the UKLEMs but it was a private event and we restricted access to the public - thus no need to comply.

How are you with soldering? Will most likely need to solder wires onto the driver to replace the spring - which is negative FYI, in case you missed that in the product description. Usually how it goes with 532nm DPSS green lasers - case is positive, the spring is negative.

I'd usually aim for something like this for this sort of project: https://www.amazon.com/532nm-3-5VDC...48155&sr=8-2-spell&keywords=green+lasermodule

Not necessarily that power output of course.

What you have is fine too!

I will try to contact the suppliers to see about the IR filter. There is a machine at the lab that can measure the power of the laser.

Yes it is very important that no one gets injured. I plan on having a motion sensor to turn the lasers off so that no one will ever in direct contact with the beams. The only remaining issue would be with the eye safety.

Personally I am not experienced at soldering. But there are plenty of people at the lab who are and who are experienced with electronics as well that will be able to set up the circuit with the laser.

Thank you for the link. If this laser doesn't work out, I'll probably buy one like that. It seems easier to work with wiring wise.
I really appreciate all the help!

FabLab said:

I will try to contact the suppliers to see about the IR filter. There is a machine at the lab that can measure the power of the laser.

What machine is it? Just want to make sure it's an actual, thermal, laser power meter. I've seen people asking about fibre optic testers - which do technically measure laser power (And losses/reflections etc) but that's not going to be suitable for testing one of these.

Yes it is very important that no one gets injured. I plan on having a motion sensor to turn the lasers off so that no one will ever in direct contact with the beams. The only remaining issue would be with the eye safety.

Motion sensor is a good idea - although if all the beams are <=5mW you'll be fine - unless someone deliberately stares into one with their eyes open for an extended time (hell mend them if they do!) - the blink reflex is fast enough otherwise.

Personally I am not experienced at soldering. But there are plenty of people at the lab who are and who are experienced with electronics as well that will be able to set up the circuit with the laser.

Great! That's good to know you have help if needed. Really - the module I linked is basically the same thing - just with wires instead of a spring. The only issue you might run into with the modules that use a spring is that they may not have a dedicated pad on the board for the positive connection. Often they just use the brass case as that connection and whatever pin is connected to the case on the diode itself to connect to the driver.

Thank you for the link. If this laser doesn't work out, I'll probably buy one like that. It seems easier to work with wiring wise.
I really appreciate all the help!

Click to expand...

Most welcome - hopefully you can get it figured out! It'd look cool I'm sure.

I was trying to find an image I saw a while back of a laser wall someone had set up with a high power RGB projector. The beams were enclosed in a perspex "box" of sorts and bounced down the middle of the enclosure between two sets of mirrors IIRC. If I find it'll I post it, may give you some inspiration.

FabLab said:

I like the idea of the fiber optics, but that would unfortunately go against the fire code as well.

Click to expand...

I just don't think the beam of a laser will be easily made visible in this situation without being dangerously powerful. It's inevitable that people are going to walk through it or something might end up reflecting the beam. Even the "5mW" DPSS modules are pretty risky.

You sure fire code won't let you put a transparent curtain of fiber optic? Fire code is usually pretty lenient in regards to curtains people can walk through in an emergency, and the only problem of visibility would be resolved by transparency. You wouldn't even have to hang them all the way to the floor.

Check this out:


Otherwise, I'd say a flat lighting product like EL tape or LED strips on the ceiling and/or floor might create a nicely visible divide for a room.

Rivem said:

Otherwise, I'd say a flat lighting product like EL tape or LED strips on the ceiling and/or floor might create a nicely visible divide for a room.

Click to expand...

Yeah! Was just thinking that too - if lasers aren't going to work one of those RGB LED strips (With the single RGB LEDs, not individual R, G and B LEDs) around the inside of the frame might look cool! No risk of someone being blinded then either.

Oh, I think the machine just measured generic power output, it's not specifically for lasers. It probably wouldn't work then.

I'm just worried about kids who might try to stare directly at the lasers which is why I'm trying to be as cautious as possible.

I really hope it works out but I'm afraid that it won't be visible!


Even the fiber optic strips would not be allowed :/ The building is leased from the school which is why the fire code is so strict.

The El tape/ RGB Led strips both look cool. It's not quite the effect I want, but I think it would still be an awesome substitute if the lasers don't work out.

So I've been looking into the El tape and the only thing that I can find seems to be sold in 1M strips. Do you have any suggestions on where to purchase it from?

FabLab said:

So I've been looking into the El tape and the only thing that I can find seems to be sold in 1M strips. Do you have any suggestions on where to purchase it from?

Click to expand...

A long time ago, I ordered 15ft from here: Home page

Might be better for ceiling or walls though. I'm not sure how well it holds up to being walked on or having things rolled over it.

If you want to do the floor, using some of the LED strips in channels would probably hold up better. If you don't want to cut the floor or tile, just put some floor transitions or reducers to smooth where the channel is a bit.

FabLab said:

Hello, I am hoping to build a laser wall and I was wondering if anyone had any advice on how to do so.
The wall will be constructed inside in an entrance way as a way to separate the hallway and the main room. The structure will need to be fairly permanent. Currently I am planning on using two 5mw green lasers reflected across two mirrors to create the criss-cross effect. I am going to try to build a box around each of the lasers to prevent people from looking directly into the beam. The default setting for the lasers will be off but they will be turned on by a motion detector when someone walks in the door. I will either then have them turn off after a certain amount of time or have the person hit a button to turn them off.

The main issue is the visibility of the lasers. The hallway can be dimmed but I am still unsure if people will be able to see the laser beams. Fog machines and misters are not ideal because they will set off the fire alarm as well as leaving residue on the floor. Any suggestions on how to make the lasers more visible? They also have to be low powered so no one gets hurt.

Click to expand...

Interesting idea but no really practical way to do it without it being problematical, expensive, and dangerous.

Is an OK idea maybe for a movie as a special effect by one method or another.

I would guess it would have been done thousands of time over already if it were possible to do a credible laser wall/partition to separate rooms in everyday liiving. Maybe a grill that can been seen in very dark conditions would work.

Yes, a few thin and weakly visable beam lines like in a alarm system probably can be done
.
Not much in the way of photos of what anyone has done on google--you can have a look here: https://www.google.com/search?q=laser+light+wall&hl=en&gbv=2&tbm=isch&oq=laser+light+wall&gs_l=img.3..0j0i30j0i8i30l3.11719.18100.0.18383.13.9.0.0.0.2.97.754.9.9.0....0...1ac.1.34.img..7.6.514.ou25_VTWgkY

This is goofy and I think you should back way up and find the root problem here.

You need a wall? Why? And why does it need to be made of lasers? Is it to keep people out? How have you ruled out all the other methods of keeping people out? Is it to warn people? How have you ruled out all the other methods of warning people?

Thank you for all the ideas. The LED floor also looks very cool.

Cyparagon said:

This is goofy and I think you should back way up and find the root problem here.

You need a wall? Why? And why does it need to be made of lasers? Is it to keep people out? How have you ruled out all the other methods of keeping people out? Is it to warn people? How have you ruled out all the other methods of warning people?

Click to expand...

It's not necessary, it was just the initial idea I had. Considering all the restrictions due to the fire code it was a good way to create a visual barrier. It is not to keep people out, only to stop them so that they can sign in before entering the main lab.