Design and fabrication of low-cost thermal imaging optics using precision chalcogenide glass molding

In the past years, developments in microbolometer fabrication technology reduced the pixel size and cost of uncooled focal plane arrays. Arrays with smaller pixels are driving thermal imaging applications towards more compact, faster (low F/#) lenses, with better image quality. Also, the lower cost of uncooled detector arrays is driving down the cost of the infrared (IR) optics, making thermal imaging more accessible to high-volume commercial applications.

Usually, the image quality of a lens can be improved by a more complex design, with more elements. However, in most commercial applications, where cost, size, and weight are important factors, compact lenses with minimal number of elements are preferred. Another important aspect in IR imaging applications is maximizing the amount of light falling onto the detector. Designs with a smaller number of elements will reduce transmission loss due to surface reflections and bulk absorption.