A "pulsed" laser designed for overhead use only was irresponsibly aimed into the crowd at a July 5 show near Moscow, according to the International Laser Display Association (ILDA). Russian press reported that approximately 30 attendees at the Aquamarine 4 Open Air Festival were said to have eye injuries from the incident.
"From video of the event, it appears that a pulsed laser was used in a completely unapproved way," said Patrick Murphy, executive director of ILDA. "It was shocking to us—any competent laser operator should know to never direct a pulsed beam towards an audience. Our deepest sympathies go out to those who were injured. Some later press accounts indicate that the injuries may not be as severe or long-term as was first reported. Nevertheless, it never should have happened in the first place."
Pulsed lasers are most frequently used for medical and industrial applications. While the beam may look continuous to the eye, it actually consists of light emitted in short, rapid and powerful bursts. Each 250 billionth of a second burst contains about 100 times more energy than light from an equivalent continuous wave laser.
Press accounts stated that the show was originally to have been over the attendees' heads. Due to rain at the festival, someone—names are not yet known—decided to rotate the lasers downwards under a tent. "Video shows that the scanning beams went directly into the audience," said ILDA Safety Committee chair Greg Makhov. "This type of laser show is known as audience scanning. This would be OK if continuous wave lasers were used, under conditions specified by international safety standards. But the laser operator at this show apparently did not know or ignored the fact that pulsed lasers must not be used like this."
Laser shows have been popular entertainment for over 40 years. In that time, there have only been two other reported incidents like the one in Moscow; both were also due to gross misuse of pulsed lasers. "Every day, lasers are safely used to create beautiful and artistic shows for hundreds of thousands of people around the world," said Makhov, who has helped write some of US laser safety regulations. "Laser shows like this are covered by laws and engineering standards from groups such as American National Standards Institute and International Electrotechnical Commission. None of these standards would allow use of a pulsed laser in this fashion."
"The safety record of ILDA and our industry is outstanding," said Murphy. "We have one Russian ILDA member, and that firm was not involved in any way with the Aquamarine show." To help reassure the public that professionally created shows are safe, ILDA is taking additional steps to further increase safety.
Effective immediately, ILDA is requiring its 150 members in 34 countries to reaffirm their knowledge and commitment to laser safety. Every member will sign a document saying they have read an ILDA-prepared safety summary, and that they will not use pulsed lasers for audience scanning. Members must also sign to reaffirm the ILDA Code of Ethics, which includes provisions for safe shows and requiring all applicable laws to be followed. Any member not signing the document will be removed from the association.
In addition, ILDA is making available safety documents on its website for laserists and anyone who wants to learn more. "Previously this was a benefit only for members; now anyone can get a good overview of laser and audience-scanning guidelines from ILDA," says Murphy.
The safety documents are at ILDA's website.
In addition, a web page has been set up with "Frequently Asked Questions" about the Aquamarine show and laser safety in general. "Anyone with questions or concerns can email or call us," adds Murphy. “We want to let people know that safe shows are common and legal, and that the Moscow show was an unconscionable use of the wrong type of laser."