Green laser IR filter

I have a green laser of around 100 mw (I bought it as a 200 mw). The dot is really bright, but it doenst burn anything. It even doen't heat the hand.

I thought that it is because it has an IR filter. I procceded to disassemble the pointer, but didn't find anything like a IR filter.

Any idea? IS needed a more powerful green laser to burn?

There are the photos:





Thank you very much!

Bubal , I have done quite a few green laser builds and I see that you have a preassembled module from China. These never have the IR filter installed I always use one. The cheapest ones I found are on eBay for $15.99 for 5, 11.5 mm square filters or $6.79 for two of the same. The 100 mw will burn black plastic, but you have to leave the spot on a target for at least a minute. The nice thing about the filters is that they have <2% transmission for 808 nm and 1064 nm and> 97.5% for 532 nm. To get a good burn you need about 200 mw-350 mw or even higher if you want something spectacular. Paul1598419

Those pens will not burn anything.

Like Paul said, no cheap chinese green pointers will have an IR filter. Comapnies like CNI, Optronics, etc. will use IR filters, but everything you find on ebay will not have one. Don't mess with the optics inside the laser, they are the crystals that convert 808nm (IR) light->1064nm(IR)->532(green). If you knock them out of alignment, good luck realigning them...at that point it would be far easier to spend 10$ on a new cheap pointer.

Can you show lenses? Maybe the filter is here.

200 mW out of this Only with 808+1064

bubal said:

I have a green laser of around 100 mw (I bought it as a 200 mw). The dot is really bright, but it doenst burn anything. It even doen't heat the hand.

I thought that it is because it has an IR filter. I procceded to disassemble the pointer, but didn't find anything like a IR filter.

Any idea? IS needed a more powerful green laser to burn?

There are the photos:

Thank you very much!

Click to expand...

Bubal, it is unfortunate that you disassembled the pointer. These Chinese pointers never have a filter in them and the parts that you show are glued together. the 808 nm laser is soldered to the driver board, next to it is the lens to focus beam on ND:YVO4/KTiOPO4 crystals that are in the center of the of the disk in the next picture, they will change the output of the 808 nm to 1064 nm at about 60% of the power, then double the frequency to the second harmonic of 532 nm at about 40% of remaining power. That means your laser diode is probably a 1000 mw IR LD. The rest are lenses that collimate the beam, but no filter. If you want to see a filter go to eBay and check items # 110887324982 and # 110931824868 and they show pictures. Putting that pointer back together is going to be near impossible unless you get extremely lucky, because the alignment is critical. My best wishes to you, paul1598419

paul1598419 said:

Bubal, it is unfortunate that you disassembled the pointer.

Click to expand...

First of all, the pictures in this thread are way too big. Your quoting the entire OP with the
huge pictures is just really bad form.

paul1598419 said:

the 808 nm to 1064 nm at about 60% of the power, then double the frequency to the second harmonic of 532 nm at about 40% of remaining power. That means your laser diode is probably a 1000 mw IR LD.

Click to expand...

I don't know where you're getting this information from. It's all wrong. Even if those
efficiency figures were right, a 1W pump would still give an output of 240mW. A 300mW
pump can give over 100mW of green under the right conditions.

paul1598419 said:

Putting that pointer back together is going to be near impossible unless you get extremely lucky, because the alignment is critical. My best wishes to you, paul1598419

Click to expand...

Have you ever actually taken one apart? Unless the crystal set pops off or gets damaged,
everything remains in perfect alignment. :spank:

The Lightning Stalker said:

First of all, the pictures in this thread are way too big. Your quoting the entire OP with the
huge pictures is just really bad form.



I don't know where you're getting this information from. It's all wrong. Even if those
efficiency figures were right, a 1W pump would still give an output of 240mW. A 300mW
pump can give over 100mW of green under the right conditions.



Have you ever actually taken one apart? Unless the crystal set pops off or gets damaged,
everything remains in perfect alignment. :spank:

Click to expand...

Yeah. I was thinking in terms of a 200 mw laser. The "efficiency" figures are correct, but they are also theoretical. So, for a 100 mw 532 mw laser with no IR component it will take a 500 mw 808 nm laser diode. paul1598419