Joel Leleve

Low cost uncooled IRFPA and molded IR lenses for enhanced driver vision

Uncooled infrared focal plane arrays are being developed for a wide range of thermal imaging applications. CEA / LETI developments are focused on the improvement of their sensitivity enabling the possibility to reduce the pixel pitch and the decrease of the system cost by using smaller optics. We present the characterization of a 160 x 120 infrared focal plane array with a pixel pitch of 35 μm. The amorphous silicon based technology is using recent process enhancement developed by CEA / LETI and transferred to ULIS. ULIS developed for this device a low cost package. The readout integrated circuit structure is using an advanced skimming function to enhance the pixel signal exploitation. This device is well adapted to high volume infrared imaging applications where spatial resolution (in term of pixel number) is less important than cost. The electro-optical characterization is presented. Besides, A unique and high precision molding technology has been developed by Umicore IR Glass to produce low cost chalcogenide infrared glass lenses with a high performance level. Spherical, aspherical and asphero-diffractive lenses have been manufactured with very accurate surface precision. The performances are comparable to those of an optic made with aspherical germanium. This new glass named GASIR offers an alternative solution to germanium for thermal imaging, especially for medium and high volumes applications. These two key technologies are well adapted to develop infrared driver vision enhancement (DVE) system for commercial application. A European project named ICAR has been setting up to exploit these advantages. An overview of the project will be given.