Q: The readings of a water-cooled laser power meter fluctuate periodically, synchronized with the laser's emission rhythm. What's the cause?
A: This is a typical water circuit connection issue. Many users connect the power meter and the laser in parallel to the same chiller, which is an improper connection method.
Error Mechanism:
1、Uneven flow distribution: When the laser's output power changes, the internal water resistance changes dynamically. The flow in the parallel circuit is redistributed between the laser and the power meter, causing the power meter's heat dissipation capacity to fluctuate.
2、Temperature cross-contamination: The laser's high-temperature return water enters the chiller and raises the overall water temperature, causing periodic fluctuations in the power meter's inlet water temperature.
Under the combined effect of both factors, the readings drift dramatically.
Recommended Solution: The power meter must be supplied with water from an independent chiller. It must not share a chiller with the laser or be connected in parallel.
