Does the Fabry Perot spectrometer's free spectral range change with distance?

  • Thread starter Thread starter Niles
  • Start date Start date
  • Tags Tags
    Spectrometer
AI Thread Summary
The discussion focuses on the use of a Fabry-Pérot (FP) cavity for spectrometry, specifically regarding the relationship between cavity distance and the free spectral range (FSR). It is noted that the maxima of the FP cavity occur at intervals of λ/2, and the FSR, defined as c/2d, varies with the cavity distance d. The participant expresses concern about whether this variation affects the spacing between the maxima during spectroscopy. Ultimately, the participant confirms their understanding and successfully derives the relevant concepts. The conversation highlights the complexities of using FP cavities in spectrometry and the importance of understanding FSR dynamics.
Niles
Messages
1,834
Reaction score
0
Hi

I have a question regarding doing spectrometry using a FP-cavity. For a fixed wavelength, the successive maxima of the FP-cavity occur when the distance of the cavity is changed by a multiple of λ/2. This we can use to look at the spectrum of light in the cavity by changing the distance. In my book it is stated that these maxima are separated by the free spectral range (FSR), which in frequency is given by c/2d.

However, the FSR naturally changes with the distance d of the cavity. Does that mean that the spacing between the maxima changes when doing spectroscopy? The reason why I ask is because I have not seen a reference mentioning this, so I am worried that I might be wrong.Niles.
 
Physics news on Phys.org
I understand it now, I figured out how to derive it. Finally some success.
 
Thread 'Question about pressure of a liquid'

Thread 'Question about pressure of a liquid'

I am looking at pressure in liquids and I am testing my idea. The vertical tube is 100m, the contraption is filled with water. The vertical tube is very thin(maybe 1mm^2 cross section). The area of the base is ~100m^2. Will he top half be launched in the air if suddenly it cracked?- assuming its light enough. I want to test my idea that if I had a thin long ruber tube that I lifted up, then the pressure at "red lines" will be high and that the $force = pressure * area$ would be massive...
View full post »

Thread 'Why is the 3 body problem unsolvable? And what will happen if someone solves it?'

I feel it should be solvable we just need to find a perfect pattern, and there will be a general pattern since the forces acting are based on a single function, so..... you can't actually say it is unsolvable right? Cause imaging 3 bodies actually existed somwhere in this universe then nature isn't gonna wait till we predict it! And yea I have checked in many places that tiny changes cause large changes so it becomes chaos........ but still I just can't accept that it is impossible to solve...
View full post »

Similar threads

Fabry Perot Free Spectral Range
Replies
4
Views
3K
I Does a Fabry Perot cavity charge in discrete steps?
Replies
12
Views
3K
Is the Fabry-Perot Interference Dependent on Pulse Duration?
Replies
2
Views
2K
I How to couple light from a very small source into spectrometer?
Replies
10
Views
1K
How Does Changing Distance Affect Microwave Path Difference?
Replies
7
Views
870
Why is a laser considered monochromatic due to Fabry-Perot cavities?
Replies
11
Views
5K
Archived Spectrometer CCD Homework: Calculate Spectral Range for m=4
Replies
1
Views
2K
A In light of new evidence, what might be behind the Casimir Effect?
Replies
46
Views
4K
Finding the Distance Between Sound and Wave Maxima at a Train Station
Replies
8
Views
2K
What is the Type of Laser Used in My Wine Raman Spectrometer?
Replies
7
Views
2K

Hot Threads

Recent Insights

Back
Top