Development of Sintered ZnS Lenses for FIR Cameras

Abstract

In recent years, far-infrared ray camera (8 to 12 μm in wavelength) have been used in security & protection fields for pedestrians and vehicles. Zinc sulfide (ZnS) is a candidate material due to its excellent optical transmittance in the wavelength regions. We developed new net-shaped lenses based on powder metallurgical processing. The resulting sintered ZnS ceramics have high-accuracy dimensions and optical surface roughness. This process enables both forming and sintering simultaneously to be done, leading to high definition image and low cost.