Uncooled infrared imaging using thin film ferroelectrics

Uncooled infrared imaging is growing into a large business for several companies. With hybrid barium strontium titanate (BST) ferroelectric detectors leading the way in lowering cost, the markets are exploding. Rapid advances in VOx bolometers in the last few years have improved NETDs below those achieved to date with BST, and VOx system prices have approached those for BST systems. When these factors are coupled with the inherently superior MTF of monolithic sensors, one would expect the market for BST sensors to be waning. However, such is not the case for two reasons. First, the markets for uncooled IR imaging sensors are critically cost sensitive, and small price differences create large sales differences. Second, the laboratory performance advantage of VOx is often not realized in the fielded systems, because of the `fixed pattern' noise characteristic of DC-coupled systems. Thus, MRTs for BST systems are often better than those of VOx systems having better NETDs. Another technology looms on the horizon, poised to offer a new option for applications with stringent stability requirements coupled with high performance. Recently written off by many because of lack of progress, TFFE technology is now beginning to show why it is such a good idea.