•
|
If Specify absolute refractive index (the default) is selected, the Refractive index, real part can be taken From material, or it can be entered directly. The default value is 1. This index is considered absolute, i.e. relative to vacuum.
|
•
|
If Specify relative refractive index is selected, the Refractive index, real part can be taken From material, or it can be entered directly. The default value is 1. Then enter the Reference temperature Tref,rel (SI unit: K, default 293.15 K) and the Reference pressure Pref,rel (SI unit: Pa, default 0). The given refractive index is understood to be relative to air; that is, the absolute refractive index is the product of the specified value with the refractive index of air at the reference temperature and pressure.
|
•
|
If Get dispersion model from list is selected, choose an option from the Optical dispersion model list. The following options are available:
|
-
|
-
|
-
|
-
|
-
|
-
|
•
|
If Get dispersion model from material is selected, the dispersion model in each domain is automatically deduced from the Material nodes and their selections. This allows different optical dispersion models to be used in different domains in the geometry, using only a single Medium Properties node.
|
For the built-in optical dispersion models, the wavelength is always assumed to be in units of microns (μm). For example, in the Schott (polynomial) model, the coefficients A0, A1, A2, A3, etc. have units of 1, μm, μm2, μm3, and so on. If another source were to provide these coefficients using nanometers instead of microns, then some manual conversion would be required.
|
2
|
Locate the default Medium Properties node.
|
3
|
From the Optical dispersion model list, select Get dispersion model from material. If the glasses loaded in step 1 also provide thermo-optic coefficients, it is important to specify an accurate value of the Temperature as well.
|
•
|
None (the default): no offset will be applied.
|
•
|
Schott thermo-optic: this is the only built-in thermo-optic dispersion model available. The coefficients used to compute a temperature dependent offset in the refractive index can either be taken From material (the default), or User defined. A reference temperature is also required. This may also be taken From material (the default), or User defined.
|