Caution
Fill in all input cells.
Choose all parameters unit.
z is algebraic. R1 and R2 are infinite (if they are plane) or algebraic. Enter "infinite" for a plane surface. Other input parameters are positive.
Positive direction is according to the sense of the horizontal arrow provided for this purpose..

n0, n1 and n2 can be either numeric values (larger than or equal to 1) or references of glasses from the catalog. If references of glasses are selected, the calculation considers the refraction indexes of these glasses at the wavelength lam defined in the current page.