Home > eBooks > Optical Design: Applying the Fundamentals > Transition from a Thin Lens to a Thick Lens
Access to eBooks is limited to institutions that have purchased or currently subscribe to the SPIE eBooks program. eBooks are not available via an individual subscription. SPIE books (print and digital) may be purchased individually on SPIE.Org.

Chapter 4:
Transition from a Thin Lens to a Thick Lens
Abstract
4.1 Introduction It was shown under Chapters 2 and 3 that the âthin lensâ concept is an extremely useful one for preliminary calculations and analysis as well as a general design tool. Determining the difference in performance between that fictitious thin lens and a realistic thick lens is an interesting exercise which confirms the statement above. We begin our exercise with a thin lens shaped for minimum spherical aberration, add a reasonable thickness, and modify only the rear surface radius to maintain the focal length of the lens. We then calculate the spherical aberration for both cases and compare the results for three fâ2, 100-mm-focal-length lenses. The first lens is made from glass with an index of refraction of n=1.5 for the visible spectrum (VIS). The second is for the infrared mid-wave region (MWIR, 3â5 Î¼m), made from silicon with n=3.4. The third singlet is made from germanium, n=4, for the application in the infrared long-wave region (LWIR, 8â12 Î¼m). 4.2 Adding a Thickness and Changing the Second Surface Radius The focal length for a thin lens (one for which its thickness is assumed to be zero) is expressed by 1 f =(nâ1)(1 R 1 â1 R 2 ).
CHAPTER 4

SHARE
KEYWORDS