# Optics problem

1. Dec 12, 2009

### BoundByAxioms

1. The problem statement, all variables and given/known data
A thin layer of a transparent material with an index of refraction of 1.27 is used a nonreflective coating on the surface of glass with index of refraction of 1.51. What should the thickness of the material be for it to be nonreflecting for light of wavelength 510nm?

2. Relevant equations
$$\Delta\phi$$=$$\pi$$($$\frac{4t}{\lambda}$$-1).

3. The attempt at a solution

Plugging in $$\pi$$ for $$\Delta\phi$$, and plugging in 510 for $$\lambda$$, I solved for t to get 127.5nm.

I think that my method of solving this problem needs considerable help. Any hints (not answers, please) would be much appreciated.$$\Lambda$$