These hazards are primarily to the eyes and skin, since the absorption in tissue of these frequencies of NIR is very superficial. There is a large body of existing literature and control technology expertise and practice in dealing with optical regions of the NIR spectrum, and effective procedures and personal protective equipment, e.g., eyewear, for many sources exist. There are, however, some technology developments that present new challenges and questions for optical frequency sources as well. The general problem of dealing with exposure to such pulsed lasers is an area for further research. Improvements in laser eyewear are needed for multiple wavelength lasers, such as frequency-multiplied lasers.
Current options are often either heavy or have poor visible light transmission.
Improved eyewear is also needed for UV-A lasers where Maximum Permissible Exposures drop dramatically below 400 nm while the absorption of common filter materials does not decrease as rapidly. The result can be impractical filter thicknesses. Research is also needed to determine the actual performance of laser eyewear and filter materials against pulsed lasers down to fsec pulse durations. It is noted that this research may disclose an urgent need for improved filter materials. These are a factor in medical and industrial laser uses, and have overlap with control technology to deal with other soots and fumes, e.g., welding fumes, which is a topic of interest to one or more other breakout groups at this Workshop.