Optimization

OSLO provides the most flexible and powerful optimization tools available, including built-in merit function generators and a choice of DLS or Lagrange-multiplier boundary constraints. OSLO Standard provides optimization of basic zoom systems. OSLO Premium has general multiconfiguration optimization for many types of complex systems .

METHODS

• Damped least squares
  • Adaptive or user defined damping
  • Derivative increment
  • Upper, lower limit and scaling of damping
• Powell's method
• Simplex method
• Global explorer
• Adaptive simulated annealing
  • Auto save the current best ASA solution
  • Evaluate the progress of ASA optimization while ASA performs background search (NT and Unix)
  • ASA cooling rate and termination level
In addition to those advanced optimization tools, OSLO's interactive design allows you to easily link any one or more system parameters (thickness, curvature, index, tilt…) to one or more analysis tools (spot diagram plot, wavefront plot, reports graphics…) through a slider .
An autofocus function is available to choose an image location to minimize spot size.

VARIABLES

There are no explicit limits on the number of variables you can define. All variables can have minimum and maximum boundary values, with independent weighting and choice of derivative increments. Available variable types include:

• Radii
• Thicknesses
• Apertures
• Glasses
• Tilts
• Decenters
• Special data coefficients (aspherics, gradient indices…)

 

MERIT FUNCTION

Each operand is defined as a weighted combination of 2 components (A > B, A + B, A*B….). Operands can be given a name, and have a show/hide output switch for display. Complicated operands can be built-up in stages, since a component can be a previously-defined operand. Operands can be assigned either constraint (Lagrange multiplier) or mimimize mode.

Component types

• Paraxial ray data
• Lens data (radii, thicknesses, etc.)
• Aberrations (chromatic, third, fifth order)
• Exact ray coordinates, angles, path length
• Reference ray derivatives, field sags
• Ray displacements, OPD, D-d
• Previous operand in list
• Average or RMS value of component group
• Spot size
• Wavefront
• Zernike Wavefront Coefficients
• MTF
• Polarization Operands
• Multi-layer thickness, refractive index, and extinction coefficients
• Compiled, full-precision user-defined operands using a CCL routine or a DLL

 

AUTOMATIC MERIT FUNCTION GENERATOR

The OSLO error function automatically generates a real-ray based error function that minimizes RMS spot size or RMS wavefront. It lets you define and weight field and pupil points or generate them automatically. It also gives you choices on monochromatic/polychromatic and single/multiconfiguration optimization.

• Field points by quadrature or user defined
• Rays by quadrature or square grid pattern
• Quadrature for both symmetric and asymmetric systems
• Check Edge thickness option
• Exact-ray distortion
• Chromatic operands by ray trace or D-d
• Append to/Replace existing error function

 

The GENII error function is based on a more optical approach to optimization. It is based on fewer rays and utilizes the maximum information from each ray traced.