Ebay greenies and IR

[FutureOne]

Hello everyone.

I recently purchased a Radiant LPM and started to measure all my green laser pointers.

It looks like most of them range from 30 to 50mW, and I'm sure a large percentage of that is IR.

I plan to buy some IR filters and retest with the filter on (to see how much mW is IR)

Let's assume a 30mW beam is actually 7mW worth of IR. Most 532mn goggle won't filter IR, so assuming a matte black surface, is there any danger from the IR coming out of the beam? This is assuming that matte black surface with the pointer stabilized on a tripod.

Would that pose any danger from the "diffused" IR reflection created?

 

[The Lightning Stalker]

A good source of IR filters is cheap Logitech webcams.

If the surface is a true matte black, there
won't be much reflected at these powers.
If the pen has a total output of 50mW and
worst-case, only 5mW of actual green 532,
that is still only 45mW of IR. Not much is
going to reflect from a matte black
surface. I wouldn't worry unless you can
see specular reflections in it, in which
case it is not really matte. IR glasses
are still a good investment, though.

 

[FutureOne]

A good source of IR filters is cheap Logitech webcams.

If the surface is a true matte black, there
won't be much reflected at these powers.
If the pen has a total output of 50mW and
worst-case, only 5mW of actual green 532,
that is still only 45mW of IR. Not much is
going to reflect from a matte black
surface. I wouldn't worry unless you can
see specular reflections in it, in which
case it is not really matte. IR glasses
are still a good investment, though.

Wow that's great info!

I have like 10 old Webcams lying around here doing nothing. I'll try a couple of their lenses and see the results I get.

I've thought about getting some goggles that filter both 532mn and IR frequencies, but they are usually very pricey.

As I don't own any significant amount of green lasers, I've never worried too much about it (the 400mW Lazerer for example, I only sparingly use it outside. It hasn't seen indoor use in over a year )

With my possible jump on the 520mW bandwagon, IR might be an obsolete issue to worry about for me.

 

[The Lightning Stalker]

Hint Hint: it is usually square and a shade of
purple.

IMHO, DPSS is not becomming "obsolete"
because it offers things direct diode
cannot achieve, at least not with current
technology.

 

[Pman]

Never heard of that source for IR lenses before. +REP. Gives me another thing to look for at places like Salvation Army.

 

[Deleted member 16589]

I meant to post this last night. I have some IR filters.

but as stated webcams and old camcorders are also good sources for filters.

 

[cncyana]

1) On average, what percentage of a 532nm laser is actually 532nm and how much is IR?

2) what nm range is the IR? I assume between 808nm and 980nm?

3) if I get a 300mW 532nm laser, approximately how much mW will be IR?

4) Do all other green lasers (e.g. 520nm and others) also emit IR?

thank you.

 

[Pman]

^ too difficult to answer amount of IR unless you purchase from a reputable manufacturer that installs an IR filter.

Lazerman, how big are those filters? All the ones I have are really small (as in maybe the size of a dime/nickel at the most). Would be very interested in a larger one

 

[cncyana]

^ too difficult to answer amount of IR unless you purchase from a reputable manufacturer that installs an IR filter.

I am considering the SKYlaser PL532nm, 300mW at laserbtb.com. I assume they use a quality IR filter.

 

[Pman]

I'm pretty sure you need to request the IR filter to be installed. Ask to make sure. They make high quality lasers. LOTS of owners of laserbtb units including myself (look for Skylaser units in my sig).

 

[mortuus]

I am considering the SKYlaser PL532nm, 300mW at laserbtb.com. I assume they use a quality IR filter.

no problem , you just add on the product IR filter and you should be safe, i would advise you to look at the 520 laser instead, they are diode and much more stable and also true green, 532 now that i have both to me is not green its more lime.. and Dpss lasers are temp sensitive just something to be aware of.

 

[cncyana]

I actually want some IR in my beam for arthritis therapy (IR penetrates deep into joints) in addition to having a green beam for superficial skin conditions like toenail fungus which 532nm is used to treat - dual purpose.

So I was going to request SKYlaser to NOT install the IR filter.

If I get a PL532nm-300mW laser , does anyone know about how much IR in mW it will put out - without an IR filter?

 

[The Lightning Stalker]

1)2) what nm range is the IR? I assume between 808nm and 980nm?

As with most ranges of the electromagnetic
spectrum, there is no definite wavelength
where the visible spectrum ends and IR
begins. The line between IR and EHF is
even more fuzzy. Furthermore, IR is
subcategorized into near, medium (mid),
long (far), and very long waves. IR can be
said to begin around 700nm and go all the
way to 1mm (300GHz). Some of the most
common and least expensive lasers in this
range are diodes (mostly near and the low
end of medium), HeNe, YAG, and CO2. There
is also Iodine COIL if you happen to be the
military or a defense contractor. Try
Wikipedia sometime. It's great.

 

[USAbro]

I could be wrong, a learning experience, but is it true that IR is not inherently bad for your eyes, just focused amount like any wavelength?

 

[Svenvbins]

I could be wrong, a learning experience, but is it true that IR is not inherently bad for your eyes, just focused amount like any wavelength?

That's correct. Generally, IR is just like green or blue, it's just invisible. The danger is in not seeing and, and thus being exposed to beams that are way too bright for you to handle - and because you don't see it you don't automatically turn away / close your eyes.

 

[cncyana]

My quick research on the internet seems to show that depending on the efficiency with which the IR beam is converted to 532nm green, the IR accompanying the visible 532nm beam can be as high as 5 to 10 times higher then the green beam.

Ex: If the 532nm beam is putting out a real 20mW, the IR accompanying that beam can be 100mW or even up to 200mW. The lower the efficiency of the conversion, the greater the IR released.