Question
I have a lens system that will be altered when subjected to the environment where it will be used. This environment will cause thermal and mechanical stress resulting in lens surfaces deforming to asymmetric surface shapes and glass materials changing refractive index as a function of volume. How do I model this in OSLO?
Synopsis
Modeling an optical system perturbed or altered by a working environment
Solution
The surface deformations can be modeled by using three different options:
- Fit the surface perturbations to (asymmetric*) Zernike polynomials and model the surface as a Zernike-type surface
- Sample the surface deformation at a series of points and enter these surface points (x,y & z locations) using a bicubic* spline surface
- Instead of changing the way the surface itself is defined, define the surface deformation in an add-on "interferogram" (*.INT) file which can be attached to any surface. Note that the *.INT file can contain either Zernike polynomial data or surface sag data in a rectilinear grid.
The refractive index changes can be modeled by defining the materials as gradient index materials where the index of refraction changes as a function of position throughout the volume of a material:
- OSLO allows the user to model materials as gradient index using a wide formulaic option. A user can choose from gradient index materials where the surfaces of constant index form planes, cylinders, spheres or combinations thereof.
- If for some reason OSLO's formulas for representing gradient index materials is not sufficient (or a more general gradient index shape is required), OSLO allows you to represent your particular gradient as a specially written program* using either CCL (OSLO's internal programming or macro language) or DLL (Dynamic Linked Libraries - programs written and compiled outside of OSLO that are linked to OSLO and control some aspect of OSLO's operation).
*Note that asymmetric aspheric surfaces and user-defined gradient surfaces are only available in OSLO Premium.
