Precision Optics Manufacturing of Large Hemispherical Domes

There are currently three different approaches under consideration for construction of multi-layer hemispherical multi-mode domes: (1) The bonded shell method using a transparent adhesive, (2) The alternate dielectric method in which a glass material is directly bonded to a hard outer dome shell with a grid at the interface, and (3) The Co-fired ceramic method- in which the metal grid is applied to green ceramics, and fired in such a way as to create the multi-layer structure within the as fired blank. The ability to perform the final optical finishing of the dome surfaces to achieve the desired ¼ wave transmitted wavefront uniformity is a significant driver in the manufacture of these domes and the focus of this effort. Under the Phase I effort deterministic finishing techniques potentially capable of producing a 7-in hemispherical dome with ¼ wave transmitted wavefront uniformity over any 4-in aperture were investigated. The Phase II effort will continue the evaluation of candidate technologies for the initial 9 month period, then downselect to the most promising method(s), further optimize the selected method and conclude with the finishing of a full scale dome demonstrating feasibility for producing up to 250 domes per month.