Correction of chromatism of dual-infrared zoom lenses

Abstract

Using the example of a simple-by-design mid-wave and long-wave dual-band infrared zoom lens consisting of three two-lens components made of silicone and germanium, the possibility of reducing chromatic and monochromatic aberrations to a level that ensures sufficiently high quality of the formed image is demonstrated at spatial frequencies of up to 25 inverse millime-ters. As one of the possible ways to modify the zoom lens, it is proposed to place a two-layer two-relief diffractive microstructure on the flat surface of the refractive lens closest to the aperture stop. The efficiency of the transition to the refractive-diffraction scheme is confirmed by the results of calculation and optimization of a zoom lens, the two-lens components of which are made of silicone and amorphous glass of the IRG26 brand..

Keywords

• dual-infrared range
• chromatism
• two-lens component
• refractive and refractive-diffractive zoom lens