Broadband Laser Filter.
Abstract
There is a need to provide eye protection to military personnel at risk from laser beams, An advanced concept in laser-protective eyewear consists of an optical interference filter that transmits only three narrow spectral bands one red, one green and one blue, and blocks all the rest of the visible spectrum including the wavelengths of all currently popular- lasers. Vision through this filter is excellent. Outdoor scenes are bright and clear and in full natural color. The effect is like that of a pair of fine sunglasses but without the sunglasses' color distortion. This program optimized the placement of the three transmission bands for best color rendition and maximum laser coverage. Two versions were developed one with narrow transmission bands for daylight use, and one with wider bands for twilight use; and 24 pairs of eyewear of each version were delivered to the Army. In addition, one goggle with transmission bands only two nanometers wide at half-height was fabricated as an experiment to see how far the concept could be pushed. The view through this goggle was far too dark for indoor use, but the view outdoors in the sunlight was astonishingly good - again like a pair of fine sunglasses. The above filters were all fabricated on flat glass lenses. The major effort on this program consisted of developing technology for fabricating them on curved plastics such as polycarbonate for use in goggles such as the Army's Sun, Wind and Dust,(SWD) goggles. Fabrication of interference filters as complex as the Tristimulus filter on plastics has never heretofore been successful because the finished filters would always self-destruct as they cooled.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 29, 1992
- Accession Number
- ADB166659
Entities
People
- John A. Brown