Long-focus low-cost lens deigned for biomedical hyperspectral camera

Abstract In this work a design of 250 mm F/20 lens for hyperspectral imaging of biomedical micro objects is presented. The designed lens consists of only standard optical elements and does not contain any newly developed component. Its low aperture and small field of view causes that image quality is limited only by diffraction and two optical aberrations – field curvature and chromatic focal shift. That is why an achromatic doublet is utilized as a basic lens component. Its residual field curvature is corrected by a Smith lens – a single plane-concave lens located near the image plane. The components are selected from commercially available ones. A distance between components was the only optimized parameter. Such layout makes the lens cheap and easy to manufacture.