Question
I would like to use custom materials for my lens design. What data do I need from the glass manufacturer in order to model it like the usual glass in the "GLASS" column of the surface data spreadsheet?
Synopsis
How to add custom or specialized materials (glasses) to a design
Solution
There are three ways to add custom material to your design:
- If you have refractive index data from the manufacturer at three different wavelengths, you can enter this data explicitly by choosing the "direct" option from the "GLASS" column for the appropriate surface.
- If you have refractive index information for the primary wavelength and information about the dispersion, you can enter this data by choosing the "Model" option from the "GLASS" column for the appropriate surface.*** Note that both options #1 and #2 allow you to define a custom glass for that particular surface. This glass can then be used on a later surface in the same design by using a glass pickup. However, these two options do not allow the defined glass to be used in an entirely different design.
- This 3rd option allows you to store a glass in your private catalog so that you have access to it in later designs: Choose "Lens>>Glass Catalog>>Update Private Catalog" from the OSLO menu. The resulting dialog allows you to enter:
- Index of refraction data using direct entry (at 3 wavelengths), or Sellmeier series or Laurent series coefficients (for index data at more than 3 wavelengths). For more information about fitting data to the Sellmeier and Laurent series coefficients, please refer to the OSLO on-line help and the command: "*glassman" (Type the command in the command line without the quotes).
- Thermal coefficient of expansion data
- Change of index vs. refraction data (Sellmeier index vs. temperature coefficients)
