Calculating the average power emitted from a laser

[toughsteel]

I have found a 5000 volt 20 milliamp laser at a Ham fest now logic tells me the power of the laser would be simply 5000V*0.02A= 10watt input then loses would maybe make it one watt. however I really doubt that it has that much power. I haven't been able to find a power supply capable either of running the thing either because the ignition voltage is 10,000 volts! I would rather find out the power of the Laser before I go on a hunt for a power supply and I'm curious on how one can calculate the power of a laser without measuring the output beam intensity.

 

[kuruman]

If you have a 20 milliWatt laser, isn't its power 20 milliWatts or am I missing something?

 

[toughsteel]

no the rating on the side says 20 milli amps 5000 volts

 

[kuruman]

OK, so you changed your units on me. The fact that you put 10 W in does not mean that you get 10 W out. I am not an expert on this, but I would assume that he efficiency of your laser is a number you will probably have to measure, not calculate. See for example

http://www.Newton.dep.anl.gov/askasci/eng99/eng99213.htm
http://www.rp-photonics.com/wall_plug_efficiency.html

 

[toughsteel]

I see that its what I thought, a measuring device however would be very expensive. I think however if I compare it to the efficiency of other lasers I end up with a very small rating around 50 milliwatts. The irony is that the thing is about 16 inches long and has a 2 inch diameter yet most likely has a rating only a few times greater than your average laser pointer. I guess they don't scale well. (Note by efficiency of other lasers I mean watts in watts out)