Some green laser pointers may be emitting dangerous levels of invisible infrared light, in addition to the visible green light, according to a U.S. government agency. The National Institute of Standards and Technology purchased three low-cost 10 mW pointers and found that “one unit emitted dim green light but delivered infrared levels of nearly 20 mW -- powerful enough to cause retinal damage”. Tests by a second NIST team “found similarly intense infrared emissions in some but not all units.”

The NIST team came up with a simple “home test” so that interested persons can test their own laser pointers. The test requires a digital or cellphone camera, a compact disc used to spread out the wavelengths, a webcam to view infrared light, and an infrared TV remote control.

At top, light from a green laser pointer is diffracted (spread out) by a compact disc and viewed with a digital camera that can see only visible light. At bottom, a webcam with no infrared-blocking filter shows this laser also emits infrared laser light (white dots). For this unit, the invisible infrared light is more powerful than the visible green light. (NIST photo)

The unwanted and potentially hazardous infrared light is due to misaligned or missing filters in laser pointers that use infrared to generate visible green light. Low-cost pointers are at special risk, due to cutting corners in design, materials or manufacture to reduce costs.

The team warns that, whether or not a laser pointer emits dangerous levels of infrared, users should “never point the lasers at the eyes or aim them at surfaces such as windows which can reflect infrared light [as well as visible light] back to the user” or others in the area.

For more information:

• NIST press release summarizing the issue

• NIST technical note A Green Laser Pointer Hazard which includes instructions on how to test to see if a green laser pointer has unwanted or excess infrared light emission (PDF format)

Tags: NIST, Infrared laser

A 250mW laser device is being marketed to police departments as a tool that can blind and disorient a subject “with a large modulating pool of green light”. The Dazer Laser from Laser Energetics is said to not cause permanent eye damage, at ranges from 3 to up to 8000 feet. The company says police, SWAT teams, prisons and military units worldwide are “ready to deploy them”. Read More...

Tags: Police, Dazzler, Dazer Laser

A teenager suffered burns and retinal damage, according to doctors writing in the British Medical Journal. The youth aimed a “high powered” green diode laser pointer into his own eyes. Both eyes were damaged with 20/35 vision, although six months later vision had returned to 20/20.

The burn site on the youth’s right eye

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Tags: UK

In early September 2009, an air ambulance pilot was illuminated by a laser while transferring a patient to an Ottawa hospital. A news report in early November said that he "suffered retinal damage ... is still off work nearly two months later .... [and] could remain off work for another three months."

It was not clear from the story what type of aircraft -- fixed wing or helicopter -- the pilot was flying at the time.

Captain Barry Wiszniowski of the Air Canada Pilots Association, stated "Our judicial system has to understand the severity of the consequences. It would be catastrophic if a pilot was impaired by a laser and lost all situational awareness."

More statistics and information from Canadian OH&S News.

Tags: Canada, Ottawa

The UK Home Secretary, Jack Straw, has warned that people found guilty of using laser pens to cause injury, can expect up to five years in prison. His statement comes after three Hampshire police officers were seriously injured when a beam temporarily blinded them.

They join many others who have fallen victim to a device that experts say is too dangerous to be used by the untrained.

At the Paris Indoor Tennis Open two weeks ago, the Australian Patrick Rafter became a victim. A laser beam shone by a spectator was directed at the player's face. The game had to be halted while he recovered. Other sportsmen and pop stars have been targetted too.

In South Yorkshire one bus company has recorded 32 separate incidents in the past month. Drivers say they have been picked out by people intent on causing an accident. Read More...

Tags: Car, Laser lout, Tennis, Bus, UK