Using Material Catalogs

The index of refraction for refractive surfaces and solids in OpticStudio may be defined several different ways. Most of this section is related to dispersion data as defined in the glass catalogs. For alternate means of defining index data, see "Alternate methods of defining dispersion data" later in this reference file. There are several standard catalogs supplied with OpticStudio, and custom catalogs may be created.

OpticStudio computes indices of refraction from formulas and coefficients entered into the glass catalogs. When you specify a glass name such as "BK7" in the glass column of the LDE, OpticStudio looks for the name in each of the currently loaded glass catalogs. If the glass is found, OpticStudio uses the coefficients for that glass, and then using the formula for the glass selected in the catalog, computes the indices at each of the defined wavelengths.

It is important to note that all OpticStudio glass catalogs assume that the index computed by the dispersion formulas is the relative index of refraction computed as a function of the relative wavelength. Relative means relative to air at 1.0 atmosphere and a reference temperature defined in the glass catalog.

For details on how OpticStudio considers temperature, pressure, and the index of air see Index of refraction computation

OpticStudio assumes that the index computed by the dispersion formulas is the relative index of refraction computed as a function of the relative wavelength.

This method may seem more complex than directly entering in the indices of refraction, but the advantages are numerous. For one, the formulas are generally more accurate than user-entered data. Catalog data is more convenient as well, requiring the user to only supply the glass name. This is a particular advantage during the glass selection phase of the design. Additionally, any wavelength may be used, even if no explicit index data at that wavelength is available. The primary disadvantage is that the coefficients must be calculated, although this data is either readily available in catalogs or easily calculated. If you have the index data for some material not in the catalog, or if you feel your data is better than the catalog data, OpticStudio will compute the coefficients for you automatically; see "Fitting index data" later in this reference file.

Next:

• Specifying Which Glass Catalogs to Use
• Editing & Reviewing Glass Catalogs
• Description of Catalog Data
• Creating a New Catalog
• Copying or Moving Glass Catalog Files
• The Glass Dispersion Formulas
• Fitting Index Data
• Fitting Melt Data
• Defining Transmission Data
• Defining Stress Optical Coefficients
• Displaying Mechanical Data
• Modeling Gases and Liquids (using material catalogs)
• Finding a Glass Quickly
• Glass Catalog Sources
• Obsolete Catalog Data
• The AGF & BGF File Formats
• Alternate Methods of Defining Dispersion Data