Thermopile laser power meters

A thermopile is simply an array of thermocouples connected in series and close together. The most common application is when a voltage is applied to cool one side of the thermopile and whatever it is bonded to.

Thermopiles for laser power measurement, however, are used in the opposite fashion. That is, a temperature difference is used to create a voltage. On one side, the material heated by a laser (or any other radiation source), and on the other side is a heatsink. The laser's energy that is absorbed by the material is converted to heat.

With the hot absorber on one surface and the cold heatsink on the other, there is a temperature difference across the thermo-electric device as the heat flows through it. This temperature difference causes the thermopile to generate a voltage. That voltage is proportional to the temperature difference, which in turn is proportional to the laser power.

At Gentec-EO, we carefully design and build the thermopiles for our laser power detectors to make sure that we offer the best performance for your application.