So much current for a cheap 5mW green laser?

[mikedelfino]

Hello everybody!

I recently begun in the green laser world Well I have a lot of red ones. I bought my first one on eBay (not the best place but the cheapest to begin...).

It's a 5mW green laser. As doing some experiments today I decided to measure how much current it used. I hooked up my multimeter and reads 280mA@2.75 volts... That seems to be a lot, so the diode uses 770mW???

Not sure about the calculation but that seems to be a lot. Let's say that the efficiency is 20%, it would say that it outputs 154mW....

In fact it's impossible, I can see the beam in a dark room but not in daylight. Or is it a big big big leak in infrared?

I hope I messed up in my calculation.

Thanks for your advice!

 

[magonegro]

You get 770mw, ok, and say 25% are going to 808nm IR Laser emission (driver also takes its piece of cake), this is 192.5mw, dpss conversion crystals takes its own loss, let's say in the end only ~20% are converted to 532nm, so ~30mw could be the peak of your laser. Seems an underrated one.

 

[mikedelfino]

Thanks, forgot the losses of the driver. What do you mean by underrated? Oh and it popped a balloon after ~20-25s exposure on a blackspot (blue ballon) but I wasn't able to repeat the experiment.

 

[iFoSh]

underrated or over-spec means it isn't a true 5mW pen. It is most likely putting out more than 30 if ur popping balloons.

 

[mikedelfino]

Ok thank you for the clarification. Those chinese... I could have got blind from their crap. Hopefully I never got any direct reflection...