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Blog Category: Joint Quantum Institute

NIST Researchers Measure High Infrared Power Levels from Some Green Lasers

Photo from an ordinary camera shows light from a green laser diffracted into several spots. The green laser pointer is visible in the foreground. (Bottom) The same vignette photographed by a webcam with no infrared-blocking filter reveals intense diffraction spots from 808nm infrared light, invisible to the eye. Green laser pointers have become a popular consumer item, delivering light that’s brighter to the eye than red lasers, but stories have circulated on the Web about the potential hazards of inexpensive models. Now, a team led by physicist Charles Clark at Commerce's National Institute of Standards and Technology (NIST) puts some numbers to the problem. In one case, the group found that a green laser pointer emitted almost twice its rated power level of light—but at invisible and potentially dangerous infrared wavelengths rather than green. A new NIST technical note* describes the nature of the problem as well as a home test using an inexpensive webcam that can detect excess infrared light from green lasers.  Read more