Optics Equation: What Assumptions Lead to n1f1=-n2f2?

  • Thread starter Thread starter Prologue
  • Start date Start date
  • Tags Tags
    Optics
Click For Summary
The equation n1f1 = -n2f2 is derived from Snell's Law under specific assumptions related to lens optics and field curvature. It highlights the relationship between the focal lengths of two media with different refractive indices. The discussion emphasizes the need to understand the context of optical aberrations when applying this equation. Key assumptions include paraxial approximation and thin lens behavior. Understanding these principles is crucial for accurate optical analysis.
Prologue
Messages
183
Reaction score
1
I keep seeing this equation pop up and I have no idea what it is or where it comes from.

n_{1}f_{1}= -n_{2}f_{2}

It looks like a take on snell's law, but what assumptions have to be made to get to this equation from snell's?
 
Last edited:
Science news on Phys.org
The formula is related to an optical aberration called field curvature. See attachment.
 

Attachments

  • Curvature aberration.jpg
    Curvature aberration.jpg
    49.2 KB · Views: 451
Last edited:
Thank you.
 

Similar threads

Undergrad Snell's law from a mechanical model
  • · Replies 12 ·
Replies
12
Views
2K
Graduate How to compute phase gradient from Snell's law?
  • · Replies 1 ·
Replies
1
Views
3K
Undergrad Prism Spectrometer Objective: Optics Question
  • · Replies 9 ·
Replies
9
Views
3K
Birefringence in in uniaxial optical media and Snell's law
  • · Replies 6 ·
Replies
6
Views
4K
Graduate Calculating the optical depth of an inhomogeous gas
  • · Replies 1 ·
Replies
1
Views
2K
Undergrad How to couple light from a very small source into spectrometer?
  • · Replies 10 ·
Replies
10
Views
2K
Understanding a Generalization of Snell's Law
  • · Replies 19 ·
Replies
19
Views
6K
Undergrad Optics: infinite light source illusion question - can you help?
  • · Replies 8 ·
Replies
8
Views
3K
Undergrad How Can I Build an Effective DIY Helmet-Mounted HUD?
  • · Replies 19 ·
Replies
19
Views
5K
Graduate The coherence length is much longer than the manufacturer claims
  • · Replies 10 ·
Replies
10
Views
2K