A thin film of MgF2 with n = 1.38 coats a piece of glass. Constructive interference is observed for the reflection of light with wavelengths of 500 nm and 625 nm.
Part A -
What is the thinnest film for which this can occur?
t = lambda/2n *(m + .5)
The Attempt at a Solution
Not sure what I am supposed to do, because of the two wavelengths. I know what to do for a single wavelength...
So this is my work for solving the problem with each wavelength
500 = 2(1.38)(t)/(m+.5)
500(0+.5) = 2.76(t)
t = 90.6
625(0+.5) = 2.76(t)
t = 113
Now that I have done this, I am not sure how to proceed. Any help is appreciated.