"laser rainbow" opinions needed

This is really interesting:
https://www.youtube.com/watch?v=Ay7yV41EB80



Any idea how it was done? Watching other videos it seems to be total of 110W laser power. I can't see clearly, but it seems to be 1 laser projector with two mirrors for each beam. Isn't a whole laser projector expensive for such project if you're just projecting single beams from each? The rest of the unused diodes, electronics and scanners in each seem like a waste of money.

And isn't that much power an overkill, even for sky projecting?

Video mapping is more of my thing, but I'm going to try to propose a similar project to a company in my local town. We only need the beams to reach around 5 km compared to the claimed 56 in that video. How much power do you think we'll need at a darker night than in that video?

Re: 110W "laser rainbow" opinions needed

Ha, nice to see this pop up again. Did some very basic research on this some time ago, because 2015 is the Unesco year of light!

Anyway, here's their site:
laserfabrik showlaser GmbH - Global Rainbow by Yvette Mattern

As for "laser projector being overkill", nah. Remember, they don't even need a full laserprojector, just a set of 2 (moving) mirrors. They can probably even use the crappy ebay ones because they don't need any fast translation at all.
Also, they're NOT using the diodes that would be in laser projectors

As for the overkill, depends on your wishes, but if you want to see it at a 90 deg angel I guess you need quite some power, especially when there's little fog or dust in the air

EDIT:
Looking at one of the pics on their site (Click me!) I'd say they don't use any scanners at all and adjust the mirrors manually.

Re: 110W "laser rainbow" opinions needed

Thanks for the link, I didn't know there was a site.

The reason that led me to believe they were using a laserprojector was the large flight cases, as seen also in these photos:
http://www.laserfabrik.com/images/p...w7deb110a192300013e0bd9a697ddbb6/IMG_2140.jpg
http://www.laserfabrik.com/images/p...697ddbb6/_R8J8724-Bearbeitet-ohneMenschen.jpg

But yeah, I agree, since the beams are static you don't really need expensive scanners, just mirrors.

Svenvbins said:

Also, they're NOT using the diodes that would be in laser projectors

Click to expand...

What do you mean?
Again, I'm not very experienced with lasers, video mapping is more of my thing. But I've been getting increasingly interested in lasers and have taken a laser safety course.

As far as I know, and correct me if I'm wrong, they would need to use custom array for knife edge combination and advanced cooling to achieve >10W single visible laser beams, which I've only seen readily available as assembled "laser modules", mostly sold and used in high power laser projectors.

The reason I thought the power was too much for a similar project was the difference in the distance (5 km vs 56). I know it's not easy thing to calculate and there are many variables (humidity/fog/dust/ambient light) that can change how much power will be needed.

Re: 110W "laser rainbow" opinions needed

bradt said:

Thanks for the link, I didn't know there was a site.

The reason that led me to believe they were using a laserprojector was the large flight cases, as seen also in these photos:
http://www.laserfabrik.com/images/p...w7deb110a192300013e0bd9a697ddbb6/IMG_2140.jpg
http://www.laserfabrik.com/images/p...697ddbb6/_R8J8724-Bearbeitet-ohneMenschen.jpg

Click to expand...

Ah, okay. I'll admit I haven't seen professional high-power projectors myself, but I'm pretty sure they still are way smaller. I'd think these boxes have the resonator(s), lots of cooling and some optics in them. Not sure though, as this also is outside my area of knowlegde

Also, they're NOT using the diodes that would be in laser projectors

What do you mean?

Click to expand...

Click to expand...

Well, instead of using 'regular' diodes which can be kept pretty small they seem to use different tech:

All laser sources are pure single line resonators or MOPA lasers. No common diode-arrays or OPS-arrays are used.

Click to expand...

Probably because of the better long term, high power, whatever they want-characteristics.

As far as I know, and correct me if I'm wrong, they would need to use custom array for knife edge combination and advanced cooling to achieve >10W single visible laser beams, which I've only seen readily available as assembled "laser modules", mostly sold and used in high power laser projectors.

Click to expand...

Correcting, but don't worry about it There are more ways to create strong lasers, such as fiber lasers. I won't pretend to know a lot about them, but I only know we've got a small box in our lab that already cranks out >10W. So whatever is in those boxes on the pictures, it must be cool

The reason I thought the power was too much for a similar project was the difference in the distance (5 km vs 56). I know it's not easy thing to calculate and there are many variables (humidity/fog/dust/ambient light) that can change how much power will be needed.

Click to expand...

Ah, okay. Thought you found the 110W overpowered for THEIR purpose, not yours.

Good luck!

Thanks for all the info.

The biggest laser projector I've seen was 40W (10W Red, 10W Green, 20W Blue) and the size was about 700x500x400cm. Haven't had luck to see inside of these machines, or how these powerful modules work inside. Those stuff cost like $50000 though (where $2000 for the scanners). I wonder how much the ones in this video costed to build or buy.

Never heard about "single line resonators or MOPA lasers" or "fiber lasers". I wonder where I can learn more (info, build, buy)? Most search results are product pages.

bradt said:

The biggest laser projector I've seen was 40W (10W Red, 10W Green, 20W Blue) and the size was about 700x500x400cm.

Click to expand...

I.... I... did not expect THAT. Oof. Shows how little I know

bradt said:

Never heard about "single line resonators or MOPA lasers" or "fiber lasers". I wonder where I can learn more (info, build, buy)? Most search results are product pages.

Click to expand...

I'm afraid it's difficult (much more difficult than diodes/DPSS) to do this yourself. The resonators would be possible (such as gas lasers) but I think that's really expensive too, and I've never heard of a DIY fiber laser :\

Maybe someone else can chime in with less "I think" and "Maybe" and more "I know" ^^

Hm, where can I learn more?

if you check CNI Lasers, Lasever, Laserwave, Kvant, they all have laser modules which are several Watts for both red, green and blue. Nothing cheap though.
But then I've also seen this: https://www.youtube.com/watch?v=53GJJHwQ8BA

And btw, the laser rainbow website info is a bit confusing:

I don't get why they went for 24.5W for cyan and at the same time only 8.5W for blue, while green is 10.5. I thought both red, green, red+blue appear brighter at same power than dark blue (44Xnm)?

Chemistry lab stands are great for doing the laser rainbow. You can hold and aim the lasers individually and independently. I love it for photography. Check out some of Brucemir's photo shoots; he took the idea and ran with it, to great effect. Highly recommended.

What's the point of using these bulky and expensive "resonator" laser if they can just build a diode laser knife edge array or DPPS? The green they use is like 10W which is like 5 1W diodes in two rows and dark blue is 12W which could be done with 4 NDB7A75 3.5W diodes. Red would require more unless there's more than 700mW diodes I haven't seen but I've seen photos of companies doing it.
Orange, yellow, cyan and bright blue would just be combining such arrays with dichros.
Right?