Caution
Fill in all input cells.
Choose all parameters unit.
Except x and y which are algebraic, all arameters are positive. Tl is smaller than "1".

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.