Infrared Coating Process Improvements for Detectors

The objective of this program is to improve the manufacturing processes and production yields of high- performance thin film coatings used in infrared imaging systems. The improvement effort will concentrate on reducing coating absorption and scatter caused by internal and surface defects. The required improvements specifically apply to IR filter coatings positioned in proximity to focal plane arrays. Our approach is to: Concentrate on 3 to 5 um and 8 to 12 um wavelength regions Employ Taguchi Methodology and Design of Experiments to improve coating quality Pulsed DC Magnetron Sputtering (PDCMS); 1 or 2 materials pairs (TBD) Electron-beam or Resistive Heat w/ and w/out IAD to develop the optimum deposition technique for 1 or 2 selected materials pairs (TBD) Diagnose and mitigate coating stress and scatter using thin film analysis tools Develop IR metrology instruments for the evaluation of scatter; This entails design and construction of an IR imaging microscope and IR angle-resolved scatter instrument. These instruments will quantify film progressive the improvements as influenced by the exercise of process and materials variables. Assemble a visible surface inspection system to quantify substrate and thin film surface roughness and surface defect densities. Demonstrate partial and complete band-pass filters with low absorption and low scatter and assess process yield and repeatability Optical Coating Solutions, Inc. and our commercial partner LohnStar Optics, Inc. have a successful history of demonstrated and commercialized sputtered MWIR and thermally evaporated MWIR and LWIR coatings and filters.  While current coating quality is very good, improvements are needed to meet the demanding requirements for IR detector systems. Once demonstrated, this improved technology will be made available immediately for all applications through our commercial partner LohnStar Optics, Inc. at www.LohnStarOptics.com.