Polychromats

Polychromatic systems extend optical correction beyond the visual spectral range normally associated with conventional apochromats.

Development Objective

With broadband electronic detectors, longitudinal chromatic aberration and the chromatic variation of spherical aberration become relevant over a much wider wavelength range. Multi-element designs provide additional degrees of freedom to control these errors simultaneously.

Published Design Example

The public DGE archive documents a four-element CaF₂ system with a 150 mm aperture and 1200 mm focal length. Published analyses demonstrate broadband optimization across the UBVRI range and beyond.

Published analysis of a CaF₂ quadruplet polychromat.

Published chromatic focal-shift analysis.