High accuracy laser power measurements: a scale comparison.

Area of Science:

• Metrology
• Optical Engineering
• Radiometry

Background:

• Accurate laser power and energy measurements are crucial for scientific research and industrial applications.
• Various measurement scales and instruments exist, necessitating inter-device comparisons for validation.

Purpose of the Study:

• To compare the performance of different laser power and energy measurement scales.
• To validate the accuracy of C-series calorimeters, an electrically calibrated pyroelectric null radiometer, and a twin calorimeter system.

Main Methods:

• Comparative measurements were conducted at specific power levels (3 mW, 9 mW, 30 mW) and wavelengths (488 nm, 647.1 nm, 351.1 nm, 363.8 nm).
• Instruments used included C-series calorimeters, an electrically calibrated pyroelectric null radiometer, and a commercial twin calorimeter system.

Main Results:

• Excellent agreement was observed between the C-series calorimeters and the electrically calibrated pyroelectric null radiometer across tested power levels and wavelengths.
• Measurements from the twin calorimeter system showed a ~10% discrepancy compared to the other instruments at UV wavelengths.

Conclusions:

• C-series calorimeters and electrically calibrated pyroelectric null radiometers provide reliable and consistent laser power measurements.
• The observed discrepancy in the twin calorimeter suggests a potential issue with window transmission correction, highlighting the importance of calibration details.