Refractive Index at Common Spectral Lines
Predefined postprocessing variables are available for the refractive index at frequently used spectral lines (
Ref. 6
):
•
n
d
is the d-line refractive index (yellow helium spectral line, 587.56
μ
m)
•
n
F
is the F-line refractive index (blue hydrogen spectral line, 486.13
μ
m)
•
n
C
is the C-line refractive index (red hydrogen spectral line, 656.28
μ
m)
In addition, the dimensionless Abbe number
V
d
is automatically defined,
The Abbe number indicates the sensitivity of the glass refractive index to changes in wavelength across the visible part of the electromagnetic spectrum. A greater Abbe number means that a singlet lens of the material would exhibit less chromatic aberration, while a singlet lens of a lower Abbe number would be more susceptible to chromatic aberration.
For more instructions on postprocessing of the refractive index in Geometrical Optics models, see
Plotting Refractive Index and Abbe Number
in the
Ray Optics Modeling
chapter.
