Manufacturers will often provide discrete refractive index data for a glass, i.e. index as a function of wavelength and temperature. This data may be used to define a new glass in ZEMAX.

If the refractive index of the glass exhibits no temperature variation, the (n,l) data can be used to define a new glass in 1 of 2 ways: either by inputting the data into a glass catalog using the Glass Fitting Tool – as described in the Knowledge Base article “Fitting Index Data in ZEMAX” – or by using the data to define a Table Glass, as described in the Knowledge Base article “How To Enter Glass Data at Specific Wavelengths”.

If the index data exhibit temperature variation, this can be addressed in ZEMAX using a multi-configuration system, as described in the Knowledge Base article “How to Model Thermal Effects using ZEMAX”. If separate Table Glass files can be used to describe the dispersion of the material at each temperature, the thermal variation of the glass can be modeled in ZEMAX by specifying the appropriate file in each configuration.

However, if the wavelength variation of the data is to be described by one of the ZEMAX dispersion models, the data must also be fit to the thermal model employed by ZEMAX. This can be also done using the ZEMAX Glass Fitting Tool, located under Tools > Catalogs > Glass Fitting.