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ArcticMyst Security by Avery

50mW Green For $65

MAD

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Sep 16, 2008
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I went outside for the obligatory night sky shot, but it was pulsing again at full power. But I'm not really concerned about high power, just a nice stable ~50mw with the ability to run for hours.

A quick noob question. Can you see mode hopping with the naked eye? I had it turned down to ~4 and it seemed like it would get a little brighter and then a little dimmer every now and then. Or is this just power fluctuations?

The heat sink did get a little warm after 30 minutes, but I had to leave my finger on it for a while to notice it. (I know, real scientific measurement technique ::) )
 





jayrob

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I'm no expert on green lasers, but I know that the crystals can get over saturated and overheated, causing this kind of mode hopping...
Jay
 

MAD

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Thanks. I'm not too worried about it. I'm just curious what I am seeing.

Can I slip one more noob question in your thread? I had asked about IR filtering in one of the other threads, but I think the thread had died out. If this unit is not IR filtered can I just put a good IR filter into the enclosure mounted in front of the module?
 

jayrob

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Maybe someone else can chime in on that one... It may already have ir filtering. Just send an e-mail or e-bay message to AixiZ...
Jay
 
P

pgstl07

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Sorry if this question has already been answered, if not:

These lasers are NOT IR filtered in the standard sense, however they do not leak IR in the same way cheap green laser pointers do. This is due to the construction of the modules which only allow IR to pass directly through the crystals. This means that the IR is contained entirely within the beam. In order to stay safe, you only need avoid direct exposure to the beam itself, which you should do anyway. If you measure the output of these modules on most power meters the reading will be for both green and IR output. I'm not sure about the ratio, but I believe that the green output is dominant. One person on this forum stated that after running the beam through a dichroic element to sparate the green from the IR they only lost 4mw of output. What this means is that only 4mw was IR, the rest green.

Placing the unit in a case with a small aperture (about 1/4") about 2-3" in fron of the collimating (output) lens will block a significant amount of the IR splatter generated by these modules, if you are concerned about it. As long as the IR splatter isn't collimated or coherent, there's not much to worry about.

The time to be concerned about IR is when it is not confined into the output beam (as often occurs with cheap green laser pointers). If stray IR is emitted from the output lens in any other fashion, you could get hit with a stray beam and not even know it until it's too late. This is due to the fact that IR is invisible, and will not provoke a blink reflex.

Also, yes, obtaining an IR blocking filter and placing it externally would be a simple fix if you are concerned about eliminating the IR. You will lose a small amount of total output power, but you would get an almost pure green output.

If you use these modules as they come, without IR filters installed, you may want to make sure your safety glasses are rated for BOTH 1064nm and 532nm.

Personally, I don't consider the IR emissions from these modules to be a huge problem, since they are well controlled and confined to the beam. This greatly reduces the danger involved, and for the price... why complain?
 
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I ordered one of these, it came today.  The factory setting on the pot was nearly all the way up.  I turned it up the rest of the way.  I dont have a LPM, but im sure im not getting much over 50mW, if that.  Here are a couple of pics.   I placed the driver board inside an empty matchbox temporarily to prevent accidently shocking myself or shorting out the board.  I will get a project box from Radio Shack tomorrow for a permanent mounting, as well as an on/off switch.

Ted
 

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