A question about IR.

[SB241]

I am new to lasers, I have read the forum stickies and used the search function. I am building a 445nm 1.8w laser. I have the proper eye protection for 445nm (eagle) but I still don't understand IR, do some wave lengths have more than others? Where can I find a chart and how can I protect myself from it.

I have read that even wearing proper glasses for my laser that IR can still pass through. Please help me sort fact from fiction.

 

[Aleksa]

IR is a spectrum of light (beyond 780nm). Infa Red. Lasers are single spectrum!
You have probably read about DPSS lasers. DPSS-diode pumped solid state. They work by converting the spectrum. A DPSS green laser for exapmple works by having 808nm as a pump then going through a crystal to get 1080nm and than trough another crystal to get 540nm. Thats when you need to be concern about the infra red passing through the crystals. If you have a direct semiconductor laser DIODE,you have ONLY a single spectrum. So if a diode is 450nm,no IR will be emitted.

Light
Amplification by
Stimulated
Emission of
Radiation

 

[SB241]

Aleksa, thank you. I couldn't find that answer anywhere. I like to err on the side of caution.

 

[Aleksa]

No worries bro. This is the best forum on the internet,you can find out anything that you need(also non laser related). Have fun!

 

[Pi R Squared]

I would also like to add that DPSS lasers because of their more complex design, break easily (don't drop it), are temprature sensitive, and the output isn't completely stable but can fluctuate some. If you want a green, in my opinion a 520nm is better than a 532nm DPSS. There are other colors that are DPSS but they are very expensive.

Alan

 

[trencheel303]

...and to answer the actual question, the 445nm laser you are building won't give out any IR, so you are fine in that department.

EaglePair goggles do come in nIR blocking range, they just cost a little bit extra and have lower VLT. As for proper IR that we can not see and is well into the micrometer wavelength, any polycarbonate will inherently block it so your existing safety goggles will work. Don't pay out the arse for 10,600nm safety glasses because they're just poly ones!

 

[marcuspeh]

I'm impressed, I must say. Really rarely do I encounter a blog that's both educative and entertaining

Just a note, this is a forum not a blog