Underrated lasers?

Andrew LB

Active member
Nov 20, 2013
So earlier today i found a laser in my closet i had bought back in 2015 that according to the label is a 532 wavelength green laser with the output power rating of 700mW. So i threw on the 'old man' glasses that came with it and messed around with it, putting some holes in electrical tape and lighting a few matches and became curious as to how strong this laser actually is. So i removed the 18650 battery and hooked up the leads from my variable bench power supply, set the volts to 4.2v and dialed up the current and was surprised that this thing was drawing 0.35A. I double checked to make sure the left display was set properly and it was on amps, not milliamps.
I used an online amps to watts calculator and according to it being 4.2v and 0.35a, the watt draw is 1.47w. Is that accurate or did i have some sort of gross miscalculation here? I never really got into lasers so my knowledge is pretty slim, but i recall 1w being a pretty stout laser pointer.


I just now remembered why i threw it in my closet and it had something to do with my concern about the cheap-o reddish colored glasses being able to block green laser light but not infrared. I never tested to see if this has an IR filter on the laser, but i guess i can shine it through the glasses and see if my welders helmet auto-darkens. unless there is an easier way to test this...


Well-known member
Oct 19, 2003
In a handbasket
The IR filter has a faint greenish cast. If you can remove the colimating lens and look at the diode, you might be able to see it if it's present.