Declaring laser power

[laserLips]

No, not at customs, after you've built it.

When I first started this I really did'nt expect to buying lasers induvidually and thought I was to scared to get anythign over 100 mw in case I burnt the house down.
But now it seem the laser I am building will be a touch over 0.6 watts. ( For me this is big ) DZZZZZZZZZZ
But when I'm fisnished, how do I specify the laser's power?
Do I add up all the MW's and say "oooh, it's 640mw of power" or should I measure the actual output. Do people use both, are their names for these two power readings?

Graham

[JimBo]

You need to measure the power unless the diodes have certificates for their output power.

Jim

[buffo]

Or you can just measure each laser individually and then add a fudge factor. So let's say you've got 350 mw of red, 150 mw of blue, and 100 mw of green. That should be right at 600 mw. To be safe, put a label that says "DANGER Laser Radiation Avoid eye or skin exposure to direct or scattered radiation. Solid State Class IV laser projector. 800 mw max output at 473 - 660 nm." If you are really paranoid, make it "1000 mw max output".

So long as your measured output power is lower than the max on the sticker, you're OK. If there is even the remotest possibility that you'll go over a half watt, make sure you affix the Class IV label, not the Class 3B one.

Adam

[JimBo]

What about the IR that quite often is there but isn't declared?
I think you need to measure to put your mind at ease.

Jim

[allthatwhichis]

What about the IR that quite often is there but isn't declared?
I think you need to measure to put your mind at ease.

Jim

I think... think, that you have to put the wavelengths your projector can/will emitt and we should use an IR filter somewhere and then you list, like Adam shows, the visible wavelengths that it is emitting, 457 - 680... I think... If you don't use a filter and are not sure all your lasers have them individually, you put the IR wavelength in you declaration sticker and documents. I thought I overheard someone say at FLEM you had to have an IR filter somewhere to get a varience...

[The_Doctor]

I thought I overheard someone say at FLEM you had to have an IR filter somewhere to get a varience...

Probably did too, it's not visible so it has no purpose in a show and is a danger. Same reason that UV lasers are cool and light up dayglo screens and such but try getting a variance for a UV laser. As far as I know, you can't. Strictly for visible range 400-700 nm only. Could get round that for UV though by back projection so long as you can prove nothing can burn through the screen even if the beam sits still and tries.

[JimBo]

The thing is that many of the chinese laser companies send lasers out without IR filters.
Over here in England we don't have the same problems as you do over the other side of the pond.
I presume Graham is in the UK, if he is he does need to check for either a filter or measure the IR.

Jim

[stanwax]

IR at the scanners need not be a problem. From my recent fiddlings it seems that you can get rid of it in the dichros within the guts of your projector.
For example - If you have a green laser with no ir filter and are using a green bounce dichro, most of the ir will go straight through - ie not be sent to the scanners. In my projector the last dichro is a red bounce dichro - and these reflect ir very well - so any ir that comes from the green or blue that has not already been lost by passing through the dichros, is bounced at 90 degrees away from the scanners.
Look at your layout and think about how much ir will actually get to the scanners and its likely to be a tiny ammount. Certainly of little concern.

Rob