US Patent # 6,918,673
Granted July 19, 2005
Inventors: Robert L. Johnson, Natalia Gorawski, Barry O'Dwyer
A hermetic filter assembly which improves filter life and environmental stability. The elimination of optical epoxies in this air-spaced filter results in reduced auto-fluorescence, improved parallelism and flatness, and improved heat tolerance. 3rd Millennium filters were originally based on this technology- currently RapidBand filters are made with a similar technique.