TCE

The TCE value is the thermal coefficient of expansion in 1e-6/K. For example, the expansion of a 10 mm thick piece of material over 10K can be calculated as TCE * 1e-6 * 10 K * 10 mm.

OpticStudio currently uses the TCE value to model linear thermal expansion independent of the temperature range being used. The catalogs values supplied by the glass vendor are usually the TCE for the temperature range from -30 to +70 degrees Celsius, but OpticStudio will use the TCE value for any temperature range.

Once a material is defined in the glass catalog, OpticStudio uses the TCE specified for that material to determine the thermal expansion of the radius, center thickness, and other data for the surfaces using the material. However, if the material is not a solid, but is instead a gas or a liquid, then generally the thermal expansion is not governed by the material properties, but is instead determined by the edge thickness of the mounting material.

In this special case, OpticStudio needs to use the TCE supplied in the Lens Data Editor to define the mounting material properties, rather than the TCE supplied in the glass catalog. This can be accomplished by setting the "Ignore Thermal Expansion" switch for the material in the glass catalog.

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• Other Parameters