System components measure physical properties of the lens such as curvature, thickness, aspheric and GRIN coefficients, etc. Any quantity that can be specified as an optimization variable can also be used as a system operand component. Additionally, surface sag, edge thickness, power, and axial length can be specified.
Aberration and paraxial data components represent the values of third- and fifth-order aberration coefficients, seventh-order spherical aberration, paraxial chief- and axial-ray heights and slopes, and primary and secondary chromatic aberrations.
Ray components are computed by tracing exact rays from specified field points through specified points on a reference surface (usually the pupil). Data for the field points are contained in the field points set and data for the reference surface points are contained in the ray set, each of which is described below. A wide variety of ray components can be used, including ray coordinates, displacements, path lengths, etc.
Spot diagram components (in OSLO SIX) are the values of the MTF or RMS wavefront error, computed by tracing a spot diagram from specified field points. The field point values are taken from the field points set, and the grid size (aperture divisions) and wavelengths for the spot diagrams are taken from the spot diagram set.
CCL and SCP components are values computed by CCL or SCP operand functions. These components allow the computation of quantities not easily specified by the built-in component types.
External components (in OSLO SIX) are values computed in functions in dynamic-link libraries written in compiled, high-level languages such as C. These functions are much faster than the equivalent CCL or SCP functions, but require more effort to develop.
Cross-reference components are the values of other operands in the operands set. These components allow the effective construction of operands with more than two components.
Statistical components are the mean (average) or root-mean-square (RMS) values of one or more operands. They are typically used in computing RMS spot size or RMS wavefront error.
Constant components are simply components with constant numeric values, and are typically used to set non-zero targets for operands.