Zinc Sulfide Thermal Imaging Lenses

Zinc Sulfide Thermal Imaging Lenses Demand for far infrared thermal cameras is growing and one of the most expensive parts of the camera is the current germanium lens. To address this feature, and to supply more affordable lenses, developments have been made with a sintered Zinc sulfide (ZnS) lens. This is not manufactured by the traditional method of vapour deposition (CVD) which is expensive and slow, but a precise sintering and moulding forming process utilising powdered material in a heated press. This process provides a perfect lens shape every time. Material, time and labour are reduced and the resulting lenses are all around the F# 1.0 to1.1 aperture providing high quality thermal imaging. The ZnS lens has excellent characteristics including high-purity FIR transmission from 8 to 12μm in wavelength, optical surface roughness of less than 0.020 μm on average and profile errors within 3 μm. In addition, a ZnS lens of this type has remarkable modulation transfer function (MTF) performance to make images clearer in detail. All the lenses are athermalised from -40deg C to +80deg C. Available focal lengths are 8.6,13, 18.8, 35mm Main features Made of materials that are low cost and easy to obtain. New forming process allows the cost of mass-production to be lower than those for germanium lenses. Proprietary optical design technology provides lens performance equal to those of germanium lenses. Temperature dispersion is low, thus ensuring good optical characteristics.