Freeform based focusing attachment for fixed focus thermal LWIR objectives (Conference Presentation)

Viktor P. Syvokin; Stan Szapiel

doi:10.1117/12.2561592

27 April 2020 Freeform based focusing attachment for fixed focus thermal LWIR objectives (Conference Presentation)

Viktor P. Syvokin, Stan Szapiel

Proceedings Volume 11403, Advanced Optics for Imaging Applications: UV through LWIR V; 1140304 (2020) https://doi.org/10.1117/12.2561592
Event: SPIE Defense + Commercial Sensing, 2020, Online Only

Abstract

Many fixed focus lenses for uncooled state of the art LWIR cameras are frequently factory set at large distance and therefore produce blurred thermal imagery when targets are closer than 80 m. To solve this issue, we propose a freeform based varifocal attachment that consists of two thin Germanium plates and is derived from Alvarez-Lohmann concept. When implemented together with our low-cost f/1.1 65 mm LWIR lens, the varifocal attachment enables sharp thermal imagery from 2 m to infinity. Extensive tolerancing study supports feasibility of this freeform device for future manufacturing.

Conference Presentation

Citation Download Citation

Viktor P. Syvokin and Stan Szapiel "Freeform based focusing attachment for fixed focus thermal LWIR objectives (Conference Presentation)", Proc. SPIE 11403, Advanced Optics for Imaging Applications: UV through LWIR V, 1140304 (27 April 2020); https://doi.org/10.1117/12.2561592

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