L
d
Adjust wavelength in Vacuum (380 nm - 780 nm)
L =
d =
λ =
δx =
Choose material
Vacuum(1)
Water(1.33)
Sulphuric acid(1.43)
Crown glass(1.52)
Heavy flint glass(1.65)
Diamond(2.42)
Other
Or adjust the refractive index(n) (1 - 2.42)
n =
λ
n
=