25 May 2007
Colin Sheppard of the National University of Singapore reviews the latest developments in the theory of microscope optics of the microscope, and addresses various shortcomings in the traditional theory.
Even though the optical microscope is a standard optical instrument, often used as an example to introduce the principles of optics, some of the assumptions that are used to describe image formation are highly suspect (J. Opt. A: Pure Appl. Opt. 9 S1-S6).
Sheppard discusses some of the assumptions and approximations that form part of the traditional theory, and how they can be far from justified in practice.
The review also describes how advances in new microscope techniques, as well as in understanding the image formation process, have led to investigations in various fields of optics. These incude diffraction theory, pupil filters, non-paraxial focusing, vectorial effects, finite Fresnel number, partial coherence, three-dimensional image formation, beam propagation, ultrashort pulse propagation and scattering theory.
Sheppard also comments on some of the areas that have yet to be investigated in depth, which include the effects of polarization in 3D imaging of thick objects and 3D partially coherent imaging.
This paper is based on a plenary presentation at Photonics06, held in Manchester, UK, on the award of the 2006 Institute of Physics Optics and Photonics Division Prize.
This forms the abstract of an article published in Journal of Optics A: Pure and Applied Optics. The full article is available here.