Journal of the Optical Society of Korea

Optical Society of Korea (한국광학회)
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Design and Analysis of a 10× Optical Zoom System for an LWIR Camera

  • Received : 2014.08.26
  • Accepted : 2014.09.02
  • Published : 2014.10.25
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Abstract

This paper presents the design and evaluation of the optical zoom system for an LWIR camera. The 12.8operating wavelength range of this system is from $7.7{\mu}m$ to $12.8{\mu}m$. Through a paraxial design and optimization process, we have obtained the extended four-group inner-focus zoom system with focal lengths of 10 to 100 mm, which consists of the six lenses including four aspheric surfaces and two diffractive surfaces. The diffractive lenses were used to balance the higher-order aberrations, and its diffraction properties were evaluated by scalar diffraction theory. We have calculated the polychromatic integrated diffraction efficiency and the MTF drop generated by background noise. The f-number of the zoom system is F/1.4 at all positions. Fields of view are given by $51.28^{\circ}{\times}38.46^{\circ}$ at wide field and $5.50^{\circ}{\times}4.12^{\circ}$ at narrow field positions. In conclusion, this design procedure results in a $10{\times}$ compact zoom lens system useful for an LWIR camera.

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References

  1. J. M. Loyd, Thermal Imaging System (Plenum Press, New York, USA, 1975).
  2. G. C. Holst, "Imaging system performance based upon $F{\lambda}/d$," Opt. Eng. 46, 103204 (2007). https://doi.org/10.1117/1.2790066
  3. J. A. Ratches, R. H. Vollmerhausen, and R. G. Driggers. "Target acquisition performance modeling of infrared imaging systems: Past, present, and future," IEEE Sensors J. 1, 31-40 (2001). https://doi.org/10.1109/JSEN.2001.923585
  4. G. C. Holst, Testing and Evaluation of Infrared Imaging Systems (JCD Publishing, Winter Park, USA, 2008).
  5. NVESD Manual and Reference Guide, Rev 7.0 (U.S. Army Night Vision and Electronic Sensors Directorate, USA, 2002).
  6. D. A. Buralli and G. M. Morris, "Effects of diffraction efficiency on the modulation transfer function of diffractive lenses," Appl. Opt. 31, 4389-4396 (1992). https://doi.org/10.1364/AO.31.004389
  7. C. M. Ok, H. J. Lee, and H. K. Kim, "Optimization of a middle infrared optical system with double magnification," in Proc. OSK Summer Meeting (Phoenix Park, Korea, Jul. 2008), pp. 397-398.
  8. A. Daniels, Field Guide to Infrared Systems, Detectors, and FPAs (SPIE Press, Bellingham, Washington, USA, 2010).
  9. R. K. Bhan, R. S. Saxena, C. R. Jalwania, and S. K. Lomash, "Uncooled infrared microbolometer arrays and their characterisation techniques," Defense Science J. 59, 580-589 (2009). https://doi.org/10.14429/dsj.59.1562
  10. S. C. Park and J. U. Lee, "Rapid optical zoom system design using optimized lens module," J. Korean Phys. Soc. 32, 815-822 (1998).
  11. K. Tanaka, "Paraxial theory in optical design in terms of Gaussian brackets," in Process in Optics XXIII, E. Wolf ed. (North-Holland, Amsterdam, The Netherlands, 1986), pp. 63-111.
  12. K. Tanaka, "Paraxial analysis of mechanically compensated zoom lenses. 1: Four-component types," Appl. Opt. 21, 2174-2183 (1982). https://doi.org/10.1364/AO.21.002174
  13. S. C. Park and R. R. Shannon, "Zoom lens design using lens module," Opt. Eng. 35, 1668-1676 (1996). https://doi.org/10.1117/1.600742
  14. S. C. Park and S. H. Lee, "Zoom lens design for a 10x slim camera using successive procedures," J. Opt. Soc. Korea 17, 518-524 (2013). https://doi.org/10.3807/JOSK.2013.17.6.518
  15. D. A. Buralli, G. M. Morris, and J. R. Rogers, "Optical performance of holographic kinoforms," Appl. Opt. 28, 976-983 (1989). https://doi.org/10.1364/AO.28.000976