Modules are conceived as building blocks in formulating optical designs with certain useful properties. This paper provides necessary and sufficient conditions for successfully combining (coupling) modules to form such a design system. Canonical ray tracing is defined, and canonical versions of aberration coefficients are derived. These are used to obtain equations for zero values of third-order-monochromatic and primary-chromatic-aberration coefficients. Their utilization in practical problems in optical design is illustrated.
O. N. Stavroudis and R. I. Mercado, "Canonical properties of optical-design modules," J. Opt. Soc. Am. 65, 509-517 (1975)