Optimisation is used to improve the performance of an optical system. The ZEMAX Optical Design Program represents the state of the art in optimisation power, flexibility and ease of use.

ZEMAX uses a powerful actively damped least squares optimisation algorithm. Any number of variables may be simultaneously optimised, using either a user defined or one of the default merit functions. An unlimited number of  independent optimisation goals or targets may be simultaneously defined, using any combination of different predefined targets.

The 20 default merit functions include RMS spot size and RMS wavefront error, referenced to either the chief ray or the centroid, peak-to-valley spot size and wavefront error. Other physically significant merit functions are available such as best MTF response or encircled energy. Frequently used merit functions can be stored separately for use with multiple designs.

The default merit function dialog box

The predefined targets include ray and construction data, as well as detailed boundary controls on lens and system data. An infinite number of different user defined targets may be created using any of the hundreds of predefined controls. The merit function may be easily edited and customised.

Optimisation over multiple configurations is simple and transparent. Equality, inequality, and Lagrange multiplier constraints are all supported with arbitrary weighting.

ZEMAX can optimise virtually any parameter in the system, including radii, thicknesses, glasses, conics, aspheric coefficients, grating spacings, apertures, wavelengths, field positions, and more.

Easy to Use

Optimisation is very simple to use. Simply define which variables ZEMAX is free to optimise. Then define a merit function using the default merit function dialog box. Lastly, simply click on “Automatic” and ZEMAX does the rest. ZEMAX chooses optimal derivative increments and damping factors automatically at every iteration.

The optimiser's dialog box

ZEMAX can optionally display and update other windows during optimisation, which provides valuable feedback of the evolution of the optical system.

Optimisation of complex zoom, illumination, non-imaging or other unusual systems is easy because ZEMAX allows full editing and customisation of the default merit functions to meet any requirement.

Global Optimisation

Global Optimisation refers to the capability of ZEMAX to seek out not only an improved design but the best possible design available for a given set of goals and constraints.

ZEMAX supports two global optimisation algorithms. The first algorithm, called global search, is used to seek out new design forms and then optimise them in search of the ten best design forms available. The search runs in an infinite loop until terminated by the user.

The second algorithm is called hammer optimisation and is used for exhaustively searching for a better variation of the current design form. Hammer optimisation is used in the final stages of a design effort to verify that the best possible design has indeed been selected.

Both algorithms use the same user defined or default merit function as the standard optimisation feature, and can be run as background tasks for effortless optimisation.

ZEMAX supports up to 16 CPUs per computer for automatic multiple-threaded execution.