Thin film interference optics for imaging the O II 834-A airglow.
Normal incidence thin film interference mirrors and filters have been designed to image the O II 834-A airglow. It is shown that MgF(2) is a useful spacer material for this wavelength region. The mirrors consist of thin layers of MgF(2) in combination with other materials that are chosen to reflect efficiently in a narrow band centered at 834 A. Peak reflectance of 60% can be obtained with a passband 200 A wide. Al/MgF(2)/Si and Al/MgF(2)/SiC interference coatings have been designed to reflect 834 A and to absorbe the intense H I 1216 A airglow. An In/MgF(2)/In interference filter is designed to transmit 834 A and attenuate 1216 A radiation. Interference photocathode coatings for rejecting 1216 A radiation are also discussed.
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Hunter
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