NIST Researchers Measure High Infrared Power Levels from Some Green Lasers
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