DIY laser power meter

[phoenix77]

This message is mainly for MILOS, but I will be happy to receive replies to anyone who can help me out. Does anybody know of an accurate/semi-accurate way to measure the power output from a laser by using a multi-meter? Seems to me I read something about being able to do that somewhere but I can't remember the way to do it or how accurate it is. If anybody knows, could you please answer me on this forum, PM, or Email me at fusedpulse@yahoo.com All replies will be gratefully appreciated & answered! And MILOS, if you happen to read this, or if somebody knows how to get in touch with him, can he please get in touch with me by PM or Email. Thank you all, very much for any assistance that you may have helped me with! Phoenix77

 

[styropyro]

There is a method by shining the laser at an LED hooked up to a multimeter set to millivolts, but it is so inaccurate you can guess the laser's power better than the makeshift meter.

 

[phoenix77]

Thanks for taking the time to send me a reply styropyro. It really irritates me when you post a question, especially one that requires a very simple answer, & nobody can be BOTHERED to take a minute or two, to shoot off a quick reply. So, THANK YOU for YOUR time,you seem like a good guy & I've read some of your answers on that OTHER forum. BTW I hardly go there anymore. This Forum is way better by far, don't you thimk so?

 

[VillageIdiot]

Oh yeah. If you're talking about LC, it's full to the brim with noobs. It actually makes me feel sorry for them when I go there to see what biased opinion they have today. I'm glad you escaped from there, man. ;D

 

[GooeyGus]

There is a method by shining the laser at an LED hooked up to a multimeter set to millivolts, but it is so inaccurate you can guess the laser's power better than the makeshift meter.

details? Can one use any color LED? It doesn't sound accurate at all but its better than nothin!

 

[Dingers]

Oh yeah,

another converted from LC [smiley=thumbsup.gif]

 

[FireMyLaser]

[quote author=styropyro link=1208550925/0#1 date=1208552832]There is a method by shining the laser at an LED hooked up to a multimeter set to millivolts, but it is so inaccurate you can guess the laser's power better than the makeshift meter.

details? Can one use any color LED? It doesn't sound accurate at all but its better than nothing!
[/quote]
You can do this (for green and blue lasers anyway), but it is only good enough to check the health of your laser. See if the out put is getting higher or lower in time. You will have to build a jig that always will hold the laser at the correct distance and lasing on the same spot every time you use it. You will need to make a diffuser and cut of the lens from the LED to make it more accurate. That's that I did to check my blu-ray. The best LED colour is orange, yellow or yellow-green. You could try to calibrate it, but I don't know if the meter will be linear.

Edit: If the laser is high power, LED might reach it's full voltage and the measurement will be useless. To prevent this you might need several diffusers (like white paper) in front of the LED to lower the brightness - experiment.