How Thin Must the Oil Film Be to Appear Red?

  • Thread starter Thread starter matt85
  • Start date Start date
Click For Summary
SUMMARY

The discussion focuses on determining the minimum thickness of an oil film (n = 1.49) over water (n = 1.33) that appears red due to thin film interference at a wavelength of 629 nm. The key condition for the reflections from the air/oil interface and the oil/water interface to be in phase is that the film thickness must satisfy the equation for constructive interference. Specifically, the minimum thickness can be calculated using the formula: t = (m * λ) / (2 * n), where m is an integer representing the order of interference.

PREREQUISITES
  • Understanding of thin film interference principles
  • Familiarity with the refractive indices of materials
  • Knowledge of constructive interference conditions
  • Basic proficiency in optics and wavelength calculations
NEXT STEPS
  • Research the formula for thin film interference and its applications
  • Learn about the impact of refractive indices on light behavior
  • Explore examples of thin film interference in real-world scenarios
  • Study the effects of varying film thickness on color appearance
USEFUL FOR

Students and professionals in physics, optics researchers, and anyone interested in the principles of light interference and its applications in materials science.

matt85
Messages
25
Reaction score
0
A thin film of oil (n = 1.49 is spread over a puddle of water (n = 1.33). In a region where the film looks red from directly above (lambda = 629 nm), what is the minimum possible thickness of the film?

______nm

Could someone please help me with this? I have no clue on this one, it was the only of the assignment I couldn't solve...

Thanks!
 
Physics news on Phys.org
thin film interference

What conditions must be met so that the reflection from the top surface (air/oil interface) is exactly in phase with the reflection from the bottom surface (oil/water interface)?
 

Similar threads

  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 13 ·
Replies
13
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
Replies
7
Views
6K
Replies
3
Views
2K
Replies
2
Views
2K
Replies
5
Views
8K
Replies
2
Views
4K
  • · Replies 3 ·
Replies
3
Views
4K
Replies
4
Views
8K