I recently bought some cheap lasers and wanted to measure the power output. I don't know why all the laser power meters that I saw for sale were so expensive, because this really isn't that complicated.
I hooked up a peltier module to a voltmeter and shined various lasers at it. The voltage gives a relative measurement of the power of the laser.
http://imgur.com/Xe1RrMz
That is a thermoelectric module on an old CPU heatsink. It would probably work better if I painted it black, but this setup is rather sensitive as it is. It can detect the heat from my hand from about 10 cm away.
The only problem is I'm not sure how to calibrate this to calculate the actual power of the laser. I need something to use as a reference. Is there a laser that I can buy that would, for example, have exactly 5 mW output?
I hooked up a peltier module to a voltmeter and shined various lasers at it. The voltage gives a relative measurement of the power of the laser.
http://imgur.com/Xe1RrMz
That is a thermoelectric module on an old CPU heatsink. It would probably work better if I painted it black, but this setup is rather sensitive as it is. It can detect the heat from my hand from about 10 cm away.
The only problem is I'm not sure how to calibrate this to calculate the actual power of the laser. I need something to use as a reference. Is there a laser that I can buy that would, for example, have exactly 5 mW output?