IR leakage in higher powered greenies

I was curious about any IR leakage in my greenies, so I shined them through a diffraction grating and viewed the pattern through a night vision camera.

I didn't see anything unusual with my lower powered greenies, an 80mW CNI PGL III-A and a Nova X150.

However, I did see additional dots with my RPL and brand new PL-D, both of which are supposed to possess IR filters.

Boosted240 also recently measured his new PL-D 500 for IR leakage by placing goggles in front of an LPM and got 82mW.

Assuming these higher powered greenies use 2.5W IR diodes and IR filters that leak 2-3%, are these IR leakage results expected? :thinking:

Most high powered greenies will leak some IR... in some cases quite a bit more than the 2-3%.

One 400mW o-like torch I had, leaked about 90mW of IR with total of ~460mW. Another 40mW of IR with total of about ~500mW.

200mW greenies that leaked ~5mW, 40mW, and ~15mW.

Have a strange dying greenie that leaks over 100mW of IR if I let it run past 90 seconds:undecided:

So to answer your question, I think those results are perfectly in line with what's to be expected. Might be that the lasers don't have an IR filter by rely on efficiency to deal with ir.

InfinitusEquitas said:

Might be that the lasers don't have an IR filter by rely on efficiency to deal with ir.

Click to expand...

wat :thinking:

romogracie said:

wat :thinking:

Click to expand...

Depending on the efficiency of the process that produces 532nm... there can be very little IR left over to leak

I can think of no other reason that two EXACTLY identical lasers will have slightly different overall output, but a drastic difference in IR leakage.

InfinitusEquitas said:

Most high powered greenies will leak some IR... in some cases quite a bit more than the 2-3%.

One 400mW o-like torch I had, leaked about 90mW of IR with total of ~460mW. Another 40mW of IR with total of about ~500mW.

200mW greenies that leaked ~5mW, 40mW, and ~15mW.

Have a strange dying greenie that leaks over 100mW of IR if I let it run past 90 seconds:undecided:

So to answer your question, I think those results are perfectly in line with what's to be expected. Might be that the lasers don't have an IR filter by rely on efficiency to deal with ir.

Click to expand...

I have a cheapish green laser that outputs ~130mW.
Should I get a ir filter for it?

TuhOz said:

I have a cheapish green laser that outputs ~130mW.
Should I get a ir filter for it?

Click to expand...

It depends on how you use the laser.

Personally I don't use IR filters in any of my greenies because even the best filter will also lower the output of 532nm a bit, and it will affect beam quality, could also affect the dot.

The big risk with IR is that most goggles do not protect against IR.

Of course the IR is also usually not nearly as focused as the visible green light.

If you use the laser for burning, I would recommend either putting in an IR filter or getting goggles that block IR...

To be honest I usually don't use goggles for lasers under 200mW... but I am VERY careful with where I point them and how I'm using them.