Caution
Fill in all input cells.
Choose all parameters unit.

n can be either a numeric value or the reference of a glass from the catalog. If a reference of a glass is selected, the calculation considers the refraction index of this glass at the generic wavelength lam defined in the page accessible by the general parameters/wavelength link.

Except x which is algebraic, input parameters are strictly positive.
Positive direction is according to the sense of the horizontal arrow provided for this purpose.