A cheap and simple Laser Power Meter LPM for small power source

Here’s a cheap and simple Laser Power Meter LPM for small power source, based on “MarioMaster LPM meter” by Davide Gironi:

This type of meter uses a ThermoElectric Cooling module (TEC) to measure the power of a laser. The TEC will absorb the laser light, and transform the heat generated by the laser beam to an electrical signal.
An operational amplifier is used then to amplify the signal and ouput it to a volt meter.
Voltage meter will display the power in W unit of the laser beam you are testing.
The TEC takes a little amount of time to heat, so wait until your reading became stable.
This type of meter is simple and cheap to build.
It can measure laser power up to 2W, with an accurancy of +-10mW.

Check out the video after the break.