Design of a Passive Heat-Rejecting Thermal ImagingLens for Long-Wave Infrared (LWIR)

The paper presents a method for calculating a thermal imaging objective lens working with an uncooled detector in the long-wave infrared (LWIR) spectral region with the ability to passively remove optical heat based on the selection of appropriate materials. The objective lens optical system consists of only 3 spherical lenses made from three types of infrared materials with different refractive indices and dispersions. The simulation results show that the thermal imaging objective lens optical system has good quality, fully meeting the requirements for image quality, with the ability to completely passively remove heat.