Maker's Name: 
Electronics Workshop UQ Physics
Where made: 
9.5 × 16 × 7.3 cm

A Peltier thermoelectric device is mounted on a two inch minifin heatsink that maintains one side at a relatively constant temperature. The other side, coated if necessary with an absorbent paint, is heated by the laser beam and generates a voltage. This is amplified by a dual op-amp LF353N, that outputs a voltage proportional to the laser power absorbed. Readout is by a moving coil meter.

Response is slow, but the sensor is not easily overloaded or damaged, and has a wide spectral range. It is especially suitable for CW CO lasers and was developed because expensive commercial power meters were continually being damaged.