Tags: IR optics, polymer optics, plastic optics, infrared optics, security

Low-cost polymer infrared imaging lens

FTI was honored to present their paper, “Low-cost polymer infrared imaging lens” at SPIE proceedings, available in the SPIE Digital Library. FTI was an early pioneer in the development of IR polymer lenses, and continues to innovate in optical designs that optimize SWaP-C in thermal imaging applications.

Today’s engineers can benefit from an introduction to polymer optics, Fresnel lenses and IR materials and their use in optimizing SWaP-C for military and security applications.

FTI presents this case study on alternatives to traditional IR lenses in the 8 to 14 μm region with a focal length of 25mm, to explore how IR polymer optics can overcome traditional cost and weight drivers inherent in traditional glass optics. Common IR materials, germanium, zinc selenide, and chalcogenides, are heavy in comparison to polymers, are not readily molded for these applications, and require an expensive anti-reflective coating due to their high refractive index. This paper lays out the optical design of a polymer IR lens made with FTI proprietary POLY IR® infrared transmitting materials, and the results of an experiment comparing the images captured with a 8-14 μm camera using both a polymer lens and a multielement antireflection coated germanium lens.

Schematic of the transition from continuous asphere to Fresnel surface. 

Arrangement of optical elements in the plastics thermal imaging lens.

Since the publication of this paper, FTI has continuously innovated and improved in the design and manufacture IR polymer lenses for a vast number of thermal imaging applications, optimizing for cost, weight and performance. Polymer optics for thermal imaging can be produced at a factor of approximately 100x cheaper and 5-10x lighter, offering potential for high-volume commercial imaging applications that must scale to high volume. Download the full paper to explore material and design considerations for thermal imaging systems. 

Read the paper or contact us to discuss your optical challenge.