Low-Cost, Multi-Spectral Windows For Tactical Reconnaissance

Technology Assessment and Transfer will fabricate a low cost targeting pod window from two pieces of polycrystalline transparent spinel optically bonded at a polished interface. Several commercially available bonding technologies will be evaluated on the basis of strength, optical transparency, and cost. Leading candidate technologies are based on hydroxide bonding, modifications to the same, and diffusion bonding. The former is a room temperature process with the latter requiring elevated temperatures. None of the existing technologies have been used to bond spinel although many have been used successfully to join other similar material. All the techniques will be developed specifically for spinel at the coupon scale. After the first year development and evaluation, down-select criteria will be evaluated and all but one vendor will be eliminated. Simultaneously, the process conditions to produce the spinel blank by hot-pressing will be optimized. At the conclusion of the two year effort, a technique will exist to bond two panels large enough to create the full-scale deliverable. Fabrication and delivery of a spinel pod window is scheduled for the option period.