DESIGN AND FABRICATION OF OPTICAL FILTERS FOR LASER FREQUENCY.
Abstract
In approaching the task of fabricating very narrow band interference filters, Spectrolab has directed its efforts during the past quarter towards the understanding of the causes and effects of film inhomogenities. For many mate rials, the conditions under which a vacuum de posited film is prepared have been found to have a pronounced effect on its optical properties. Therefore, the effects of pressure and deposi tion rates were studied. Uniform films over a relatively large area have been obtained for con stant pressure at 5 x 1/100,000 mm Hg. However, it is felt that even better uniformity could be obtained at pressures below 1 x 1/100,000 mm Hg. Also, because the amount of absorption in zinc sulfide films varies with the rate of deposition, some effort was devoted to find an optimum rate at which to deposit the films having the smallest amount of absorption. Preliminary results have proven that a rate of approximately 20 ang stroms/sec. will produce films which are non-ab sorbing in the visible. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 24, 1963
- Accession Number
- AD0412546
Entities
People
- Noel Bowman
- Samuel J. Holmes