Laser Art Exhibit

[rickyk586]

Hey everyone! I'm going to a 3 day art event called Youtopia in San Diego. It's similar to Burning Man but much smaller.

My idea for an exhibit to bring was involving lasers, because they're awesome and everyone loves them . There are a bunch of trees around so my plan was to have laser beams bouncing between mirrors attached to trees. So, I bought 10 cheapo green lasers ($5.40 a piece), 100 3"x3" mirrors, and refrigeration hose for attaching the mirrors to the trees and allowing us to bend and adjust the mirror angles.

So we tried it last night in a park and came across a couple problems. One is that the lasers became pretty dull after about 10 minutes. After some googling I see that they are not designed for continuous use at all. So my first question is: Is there a way I can keep these lasers on for a few hours? As far as batteries go, they normally take 2 AAAs so I rigged up 2 Ds instead which worked, but after about 10 minutes the laser got pretty hot and it also got pretty dull. I was thinking maybe they got dull because of the heat, but they also got dull using the AAAs but it didn't get hot (only slightly warm). After cooling down, the laser worked normally. I understand that continuous use will also shorten the lifespan of the lasers, but I'm not too concerned about it because of how cheap they were.

The other problem we had is not nearly as important, but I figured I would still ask about it just in case anyone had any pointers. The glass on the mirrors is kinda thick and therefore only allowed the laser to bounce off of maybe 4 of them before the beam was not visible anymore. Is there anything I can do about this besides buying much more expensive mirrors?

Any input you have is appreciated. Thank you very much! Also I can provide pictures if anyone asks.

 

[swamidog]

and i was just in san diego on friday running lsx laser shows at a company i can't mention.

it's hard for me to imagine the trees would hold still enough to keep the lasers targeted to the bounce mirrors.

those little green laser pointer cores have no thermal management and are designed for light duty (ha!) only. you might be able to passively cool them with larger heat sinks, but i doubt it. you could manage that with low power red or blue diodes, but they will not be visible at the same power level as the green.

unless you have a log of fog/smoke/dust/etc in the air, the beams at eye safe (read: low power) levels will never be very visible.

if you scale up to nice bright lasers (=>5mW) you will need to be concerned about safety and permits.

Hey everyone! I'm going to a 3 day art event called Youtopia in San Diego. It's similar to Burning Man but much smaller.

My idea for an exhibit to bring was involving lasers, because they're awesome and everyone loves them . There are a bunch of trees around so my plan was to have laser beams bouncing between mirrors attached to trees. So, I bought 10 cheapo green lasers ($5.40 a piece), 100 3"x3" mirrors, and refrigeration hose for attaching the mirrors to the trees and allowing us to bend and adjust the mirror angles.

So we tried it last night in a park and came across a couple problems. One is that the lasers became pretty dull after about 10 minutes. After some googling I see that they are not designed for continuous use at all. So my first question is: Is there a way I can keep these lasers on for a few hours? As far as batteries go, they normally take 2 AAAs so I rigged up 2 Ds instead which worked, but after about 10 minutes the laser got pretty hot and it also got pretty dull. I was thinking maybe they got dull because of the heat, but they also got dull using the AAAs but it didn't get hot (only slightly warm). After cooling down, the laser worked normally. I understand that continuous use will also shorten the lifespan of the lasers, but I'm not too concerned about it because of how cheap they were.

The other problem we had is not nearly as important, but I figured I would still ask about it just in case anyone had any pointers. The glass on the mirrors is kinda thick and therefore only allowed the laser to bounce off of maybe 4 of them before the beam was not visible anymore. Is there anything I can do about this besides buying much more expensive mirrors?

Any input you have is appreciated. Thank you very much! Also I can provide pictures if anyone asks.

 

[cantthinkofone]

Yeah.... There is no solution for the mirrors. You could water cool the lasers for 1,000 dollars. Sorry but not many cheap solutions.

 

[rickyk586]

and i was just in san diego on friday running lsx laser shows at a company i can't mention.

it's hard for me to imagine the trees would hold still enough to keep the lasers targeted to the bounce mirrors.

those little green laser pointer cores have no thermal management and are designed for light duty (ha!) only. you might be able to passively cool them with larger heat sinks, but i doubt it. you could manage that with low power red or blue diodes, but they will not be visible at the same power level as the green.

unless you have a log of fog/smoke/dust/etc in the air, the beams at eye safe (read: low power) levels will never be very visible.

if you scale up to nice bright lasers (=>5mW) you will need to be concerned about safety and permits.

Nice. I hope you enjoyed your stay in San Diego!

We will be fixing the mirrors to the trunks of the trees, 1' to 8' from the ground, so we're not too worried about the trees moving. During our first trial, we were able to successfully mount the laser and 4 mirrors and were able to still see the beam, granted not very well and not really from 90 degrees, but still good enough for us.

Using heat sinks is a good idea. I think it's a possibility that it could provide enough cooling because with the AAAs it really didn't get that hot (although I didn't feel the temperature of the actual diode so maybe it was getting very hot).

fog/smoke/dust is also a great idea. There's no electricity there and we're trying to do this on the cheap so we're still looking into our options for this.

I would absolutely love to scale up to a brighter laser for this but yeah, I would be too worried about safety.

It seems like heat sinks are the best possible solution so far for keeping these lasers on for a while so thanks for the idea!