HELP need to lower output on a 50mw green laser

Hi there, as the title say i need to decrease the output on my laser.

Specs:


- Green Laser sight unit
- Wavelength: 532nm
- Max output: 50mw
- Length: 11 cm
- Beam Diameter : 1.2 mm
- Beam Range : 25 miles
- Windage & Elevation Adjustment
- Material: Aluminium metal
- Use CR123A 3V Lithium Battery


this is the laser i just bought.
i do not know much about lasers yet but i was told that 50mW was harmful to the eye, and would burn it in ½ a second.

if anyone knows anything about decreasing the output or any other ways to make it safer.
I am most interested.

hobe you can help.

Look around for a screw somewhere. Open it up and post a picture. Thanks.

sure thing, i'll post pictures as soon as i get a hold of a camere, hopefully real soon.

thanks for showing interest.

Usually we see the opposite of this question, as people usually want more power.

One option would be to get saftey goggles/glasses. Glasses made specifically for green laser protection can be purchased for $68 shipped from Wicked. Or you can get some Tool King or DeWalt red laser enhanser glasses for aroung $15 - these are not specifically made for green lasers protection, but effectively block non red light effictively. I actually use the DeWalts ($6 off ebay), and all I can see os a faint red dot(105mW). I would recommend using goggles for any power over 5 mW.

If you want to mod your laser, post a picture. Also, where did you get it? Certain models will have a "pot" screw, which allows you to add/decrease the strength of the laser. There are risks involved, as you could fry your laser in the process, rendering it useless. The first place to look is usually under the power button.

A little more info (picture, brand, where you got it) and people will be able to help more.

this is the laser i bought.
FULL SET OF GREEN LASER 50mw Lithium Power Pointer

i bought it on Ebay.com

you might be able to view the link
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=220027392600&ssPageName=STRK:MEWN:IT&ih=012

i think i'll try the red laser filter to see what it does.
is there a way to messure the output without any expencive equipment?

it might not even be 50mw green, the power might be due to no filter as most ebay garbage, which is REALLY bad on your eye and has a differnt nm range by over 300nm. YAG goggles are probably 4x what you paid for the laser. this looks alot like one Jack tested that had no Ir fliter. bad news

Are you mounting it to an air soft or air rifle? Make sure you are careful of other poeples eyes as well as your own.

The only accurate way to test inexpensively is to take it to a local university with a friendly physics dept, or send it to a fellow CPF'er with the means to and is willing to test. Have them check for IR as well. A lot of the higher powered lasers on eBay don't have an IR filter, or one that is inadequate. This practice gives the laser the appearance of higher power, but most of the power is IR vs the 532nm wavelength (green). I've never seen a review of your particular model, but I would be careful until you know one way or the other.

Also, I could not tell you if that model has a pot or not. I've never seen one in person or in a review(assembled or disassembled).

If you bought this to use on a gun, these higher powers are not that desirable because you do not want to be targeted by the recipient of your laser following a brilliant green laser beam back to you, and subsequently hosing you down.

The_LED_Museum said:

If you bought this to use on a gun, these higher powers are not that desirable because you do not want to be targeted by the recipient of your laser following a brilliant green laser beam back to you, and subsequently hosing you down.

Click to expand...

Plus; looking back along the beam towards the laser is where it appears the brightest, so it will look brighter to your opponent than yourself. That's of course assuming it will be in a dark environment - in bright daylight outside, no beam will be visible. (Except perhaps very early in the morning or at dusk)

Cheers,
Erling

it will be used on our training weapons, yes some say airsoft.
hehe
the visable laser beam is needet for the scare factor as well as ir.

when you say that they have no IR filter, do they not get invisable to the eye if you pass em throug an IR filter?
i've seen that before and that's one f the reasons we use green laser cause the red will still be visable throug the filter as a red dot.
will a 50mW still be visable with an IR filter mounted and would that be a solution?

Sounds like you need a filter from Edmund Optics

http://www.edmundoptics.com/US/

Request a catalogue, they are GREAT

Owen

Raw_force said:

it will be used on our training weapons, yes some say airsoft.
hehe
the visable laser beam is needet for the scare factor as well as ir.

when you say that they have no IR filter, do they not get invisable to the eye if you pass em throug an IR filter?
i've seen that before and that's one f the reasons we use green laser cause the red will still be visable throug the filter as a red dot.
will a 50mW still be visable with an IR filter mounted and would that be a solution?

Click to expand...

An IR filter blocks most of the IR, but has no affect on the green laser light. Putting an IR filter into the unit will not solve you problem, 50 mw's of green light is still bright enough to cause injury alone. If you use eyewear that blocks the green with IR filter combined you won't see anything. The wavelength produced by the diode is at best marginally visible. The easiest method to reduce exposure hazzard would be to increase the beams divergence. I won't describe how that's done since it is very easy to do, I'll let you figure that out.
BTW, a 5 mw unit would have been adequate for your purpose.

hehe that sounds simple
but i'm not good at this stuff, could you link me or describe how it is done please.
thanks for all the responses.

Increasing the divergence will solve one problem (perhaps), but will create another one. You won't be able to target as effectively with a large spot instead of a single dot.

The easiest way of increasing divergence is by using a diverging lens, or a converging lens too. Or, if that unit has adjustable focus, you can unfocus it to give a larger spot on a far away wall.

Also, using safety goggles while "war fighting" is not wise either, as most of the light is filtered and the visibility is reduced. You will see mostly in red, which is a bit uncomfortable. Contrast will also be reduced.

Your best bet is to physically lower the output by reducing the current reaching the laser diode. For that you will certainly need to open it somehow.

i got my camera today and will post pictures later tonight, thank you all for caring.

Yep, the easiest way to reduce the output will be to control the current or voltage. Inside the laser on the driver board, there may be a potentiometer (pot) which you will want to turn down a bit. This should reduce the output to your liking. As mentioned it will require you to open up the laser, but it can be done cleanly if you do it carefully. Sometimes there is glue or epoxy holding the module in the casing, you can use acetone to work it out.

You will want to read up in the forum first on the procedure, but this should enable you to get the desired effect.

If the laser does not have an IR filter, then it may already be below 50mW in the 532nm range. However even if it's 20mW, it is to bright for your purpose. Before taking it apart to lower the current, check to see if it has an IR filter. The IR filter will look like a green/blue glass. If it does not have one, you will want to first get one and install it. After that, then go through with lowering the current.

Also, I know this is a bit off topic from your question, why not use a red laser instead? Due the the delicate nature and brightness of DPSS greens, I find red lasers work better for your application.

we mostly use the green laser for the scare effect, also anyone in denmark can buy a red laser, but a green is almost only used for my guys.
the green laser also has a use when a strong IR filter is applied, we use this for night operation, the IR is only visable to nightvision.

i tried to look for the IR filter, but i can only find what looks to be only a clear plastic plate.
is the IR filter a small piece mounted on the diode?
it looks like there might be something there. but once again i'm not really a laser tech guro.

i appreciate your answer.

This is what an IR filter from a DPSS laser would look like.

well the pictures are not showing much, the adjuster thingi is that like a little + scrue.
and how much and what way should i turn it to decrease output.

ahh no worries i found out and it worked beautifuly, thanks guys...