Polarization, minimum thickness of a quarter wave plate

[ProPatto16]

Homework Statement

show that minimum thickness of quarter wave plate is d=$\lambda$₀/4(n₁-n₂

Homework Equations

$\lambda$₁=$\lambda$₀/n₁
$\lambda$₂=$\lambda$₀/n₂

The Attempt at a Solution

for quater wave plates wavelengths must differ by 1/4
i can see its simple but i just can't see what i do

 

[ProPatto16]

no ideas?

 

[Charles_Chen]

We do have software to calculate the thickness for wave plate, different wavelength design.

charles.chen@photonik.com.sg