| NIST's new calibration service for high-power lasers up to 10 kW is controlled from behind a protective barrier. The laser is visible here in the upper left corner of the right-hand screen. Paul Williams (left) and Joshua Hadler operate the service. (Credit: Burrus/NIST) |
The Quantum Electronics and Photonics Division of the National Institute of Standards and Technology (NIST; Boulder, CO) has launched a new calibration service for high-power lasers such as those used in industry for materials processing, as well as in the military.
NIST, which is the only national metrology institute in the world to offer calibrations for laser power and power meters above 1.5 kW, is now offering the new service for power levels up to 10 kW.
10 kW IPG fiber laser
To establish the new service, NIST staff bought a 10 kW 1060-nm-emitting YLS-10000-Y13 fiber laser from IPG Photonics (Oxford, MA) and extensively renovated a laboratory to meet electrical requirements and add appropriate safeguards, such as walls with high damage tolerance and custom optics and beam controls for the laser. Operators view the running laser from behind a protective barrier using a multicamera system for monitoring and control. Laser light is absorbed by a conventional calorimeter surrounded and cooled by flowing water. The temperature difference between the incoming and outgoing water is measured and the value used to calculate the laser power.
NIST recently completed its first high-power calibration, for a commercial 5 kW laser power meter. The measurement had an uncertainty of about 1% over two standard deviations, the accuracy and precision threshold necessary for military and advanced manufacturing applications. "That level of uncertainty at multikilowatt levels is unprecedented," calibration leader Josh Hadler says.
Research into laser welding
NIST also plans to use the new facility for research on the fundamental physical processes that occur during laser welding. The study could help overcome technical challenges such as welding of materials that are dissimilar or have different thicknesses.
NIST is also developing faster and more portable laser power meters for use with kilowatt lasers, which may eventually be used as transfer standards for the new service, says project leader Paul Williams. This could enable NIST-calibrated measurements of high-power lasers to be performed in commercial labs or national metrology labs in other countries.
For technical descriptions of NIST laser calibration services and staff-contact information, see www.nist.gov/pml/div686/calibrations/laser.cfm.
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