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1 January 1991 Importance of dispersion tolerances in infrared lens design
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Proceedings Volume 1354, 1990 Intl Lens Design Conf; (1991)
Event: 1990 International Lens Design Conference, 1990, Monterey, CA, United States
The sensitivity of infrared optical designs to errors in dispersion is explored through the use of examples. The main cause for a high sensitivity to dispersion tolerances in achromatic designs is explained. Conditions for alerting the optical designer to the need for including dispersion tolerances in the design process as well as to suspect raw refractive-index data for an infrared material are provided. 2. OVERVIEW OF CONCEPTS Dispersion tolerances (dV) rarely limit the performance of optical systems used in the visible spectral band. An optical designer might consider dispersion tolerances on the glasses in a visible-band design when the design has a very high-performance specification and/or when there is very little performance margin for tolerances. In infrared (IR) designs dispersion tolerances are even more rarely considered for the materials. It is also unusual to tolerance the bulk refractive index change (index tolerance dn) for an IR design. The need for dispersion tolerances are analyzed in this paper to highlight for the optical designer the situations and motivations for including dispersion tolerances in the evaluations of optical designs especially in the infrared. Achromatic optical systems in the infrared show a wide range of sensitivity to changes in dispersion. The sensitivity is driven by V-number difference (LV) of the materials used to achieve achromatization and to some extent by aperture diameter and f-number. Therefore the sensitivity to change in dispersion of the materials
© (1991) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Ronald J. Korniski and Kevin P. Thompson "Importance of dispersion tolerances in infrared lens design", Proc. SPIE 1354, 1990 Intl Lens Design Conf, (1 January 1991);

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